GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Jim Holmgren on June 12, 2019, 12:36:17 PM
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Hi all!
I have been speculation a bit and I think that the .223 may be the easiest and cheapest option for someone who whant to get into bullet shooting!
So here are a list of advantages!
1. There are plenty of cheap .22lr liners in lenghts up to 28" for some tens$
2. The twist rate is commonly 1-16 which is good for bullets in 30-40gr range.
3. The grove dia is commonly .223 (some are .222) and there are cheap ammo available and some bullets molds exist too and sizing bigger .224 bullets should not be a problem if needed.
(Link 250 bullets for 8$ https://northamericanarms.com/shop/parts/cbb3/)
4. Full bore porting in .22 is easy and possible in almost all production airguns!
5. The hammer energy need to open the valve should be possible to get easily in production airguns.
6. Most stock parts will work fine, as example the bolt probe and some magazines from .22 airguns.
7. The lower Fpe level needs a smaller plenum, which is common on cheap pcp guns and it also simplifies the construction in a regulated setup.
Start with airrifle with 200bar/3000 psi fill pressure or a cheap co2 rifle with a pcp conversion.
So for a airrifle in the 60-100fpe range, the .222/.223 cal whould be great choice for a minium of head scratching and weight reduction of you wallet ;).
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Test your hypothesis and build one.
I think everyone would learn a lot.
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Jim, I have long been a proponent of .224 as the caliber of choice for long range airgunning where over 100 FPE is not needed.... The SD of a .224 cal bullet is lower than the same shape bullet in .257 cal, so less pressure is needed to achieve the same velocity.... Conversely, for the same pressure and SD, a .224 cal bullet is proportionately longer and slimmer, so can have a better BC.... Since wind drift is proportional to BC, what's not to like?....
I haven't played around with .22LR barrels, the only .224 cal I have used is the 14" TJ's barrel (and more recently I had Mike make me a 9" twist for long, heavy bullets)…. However, what you say makes sense, and most of the .224/.225 bullets can be sized down to .222/.223 without issue.... The venerable Lyman 225107 is a wonderful bullet, and NOE make them under the number 225-39 (formerly #225-37) and they have some moulds with a Lyman HP pin in one cavity, and it weighs 37 gr....
(http://noebulletmolds.com/NV/images/N.O.E._Bullet_Moulds_225-39-FN_GC_B2__Cust.Jpg)
http://noebulletmolds.com/NV/index.php?cPath=24_117 (http://noebulletmolds.com/NV/index.php?cPath=24_117)
I am trying to convince Al that he need to make them in RG2 and RG4 moulds with (optional) HPs in all cavities.... They work perfectly in a 14-16" twist, and should even be OK in an 18".... All your points in your post are right on the money, IMO....
Bob
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.222 Rem and .223 Rem barrels are also reasonably priced while providing faster twist rates needed for longer bullets. Here's my build, a 2003 BSA Hornet heavily modified with LW .222 Rem barrel. Makes 100 fpe with 47 grain 225420s when all wound up:
(https://live.staticflickr.com/65535/48035435632_18e08291d8_b.jpg) (https://flic.kr/p/2gbJau5)224-br (https://flic.kr/p/2gbJau5) by abbababbaccc (https://www.flickr.com/photos/11843711@N08/), on Flickr
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Thanks for you opions!
I did this post as there seems to be a great interest in bullet-shooters these days and this is the easiest diy setup that I could come up with.
I'm actually doing a .224 build with 1-12"twist as I want to test bullets up to 55grains, I will post the results when it's done.
Beautiful rifle RKR!! Looks great in that benchrest stock!
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That Rifle looks good Ric!
Tofazfou and I discussed and played with the idea of a .224 years ago. He and i went in different directions. While both went with the .257, I still want to go .22. Tof. Went with the 172 HmAir, and man, what a shooter it is!
I've long been a proponent of the North American Arms black powder .22 bullets. It's a deal that can't be beat! ;)
Knife
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This is an old topic but one that I’m sure lots of people are interested in. I’ve been interested in having a .223- .224 build and those slugs from northamericanarms are are indeed very well priced. Has anyone had anything feed back on a build that sings those slugs?
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My suggestion is start out with a PCP and not a conversion. There's enough entry level guns out there, that you will be many $$ ahead. It's also going to take a lot of power to push the 55 grain bullet that hard in a .22. Your probably looking at a single shot for a 55 grain bullet. You must make sure the magazine will handle the length of the bullet, 55 grain that is, if going .22. I know Bob has made some beast's out of a Discovery platform, and they have aftermarket parts to make them howl.
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I have more PCPs right now than under wear. Was just wondering on a .223/.224 build if anyone has had luck with the Northamerican arms slugs. They are .224 and weigh 30 gr. I have shot them out of a steroid AR6 that Will Piatt tuned for me. Don’t remember how they did but with the 32 grain EunJins it’s a 70 FPE beast (and very accurate with the EunJins). I like to take things to the next level.
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It's not that difficult to get into the 80 FPE range in .224 cal, which means up to 40 gr. slugs.... and they are short enough to function in many mags.... If you make that next step up to the 47 gr. 225420 or heavier, the slugs are over 0.500" long, and you need more pressure and/or a longer barrel to get decent velocity with them.... It can certainly be done, but you need to think about the entire process and requirements before you commit to that next level of bullet weight and FPE....
Bob
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One of the slug barrels in my Little Mini Raptor is a .223. It acutally mic's to .2213 and is deadly accurate.
I have some of the NNA bullets here, but have not used them in this build yet. so far, I hve been using slugs from two different molds from NOE that I decked to get te weight I wanted.
One is 29 gr. and one is 39 gr's. Both are accurate.
Odd thing happened in testing. I bought these barrels from Brownells. the are Liners that I pressed into heavy walled CF tubing.
One is 1 in 16, the other 1 in 20. The one in 16 is supposed to be the best for the slugs Iam using. Oddly enough, the 1 in 20 out shoots two different 1 in 16's regardless of the length or weight of the slug. Odd!
Odd indeed!!!
Knife
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Maybe in the future a .223 Raptor will be added to the heard. From what it looks like, everyone and their grandmas are trying to unload their PCPs, most likely to collect enough bubble gum money for a Raptor. Hence, the lower than expected resale value of ones’ beloved AGs. Knife, have you tried the .224 Northamericanarms bullet in your .223 Raptor? If you’d like, I’ll send you some from my pile for you to try out. N/C. Just curious to see how they would do.
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hey-Hey!!!,
The TJ 1 in 14" .224 barrel shoots the NAA swagings very well. I built a marauder around that barrel, and ran it well over 100 FPE with 46 gr cast from a 225353. What I discovered I want is a '353 with a gas check shank. The flat base does not leave cleanly, and thus accurately.
That rifle is now 30 cal, and it does 1000 fps with 50 gr JSB quite easily. The .224 was more fun to play with, as there were more issues to solve...:)
When casting .22 and other small stuff, you will need new sprue plates for Lyman molds; their hole is too big, and it deforms the back of the bullet when it cuts. More like bend and tear. I found some folk on CastBoolits who made me some new ones from 3/16" 4140 and man are they nice.
cheers,
Douglas
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Thanks PakProtector. V
hey-Hey!!!,
The TJ 1 in 14" .224 barrel shoots the NAA swagings very well. I built a marauder around that barrel, and ran it well over 100 FPE with 46 gr cast from a 225353. What I discovered I want is a '353 with a gas check shank. The flat base does not leave cleanly, and thus accurately.
That rifle is now 30 cal, and it does 1000 fps with 50 gr JSB quite easily. The .224 was more fun to play with, as there were more issues to solve...:)
When casting .22 and other small stuff, you will need new sprue plates for Lyman molds; their hole is too big, and it deforms the back of the bullet when it cuts. More like bend and tear. I found some folk on CastBoolits who made me some new ones from 3/16" 4140 and man are they nice.
cheers,
Douglas
ery
Thanks for the info. What internals did you use for that monstrous .224 MRod you had? (or still have as a .30).
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I made a .224 sentry. It has a 1:14 TJ's barrel, it shoots everything from 39gr to 62gr cast slugs very accurately. I haven't found a round it doesn't like yet, very forgiving barrel
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Maybe in the future a .223 Raptor will be added to the heard. From what it looks like, everyone and their grandmas are trying to unload their PCPs, most likely to collect enough bubble gum money for a Raptor. Hence, the lower than expected resale value of ones’ beloved AGs. Knife, have you tried the .224 Northamericanarms bullet in your .223 Raptor? If you’d like, I’ll send you some from my pile for you to try out. N/C. Just curious to see how they would do.
I appreciate it! I do have some on hand. If it will ever stop poring down rain, I will test them in this new barrel. ;)
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To make an easy .224 bullet shooter conversion, I would suggest starting with a Winchester 70/35. It can make the power needed and magazines are long enough for almost all cast bullets. It also has airtube that matches medium size bottles. It's just a matter of rebarreling, new bullet probe + sleeving the magazine.
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If I were to do it again I would start with a M10, its pretty much ready to go with all the hammer energy you'll need and still a pretty cheap starter gun
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If I were to do it again I would start with a M10, its pretty much ready to go with all the hammer energy you'll need and still a pretty cheap starter gun
Can you fit .52" bullets in the magazine? http://arsenalmolds.com/bullet-molds?product_id=165 (http://arsenalmolds.com/bullet-molds?product_id=165)
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If I were to do it again I would start with a M10, its pretty much ready to go with all the hammer energy you'll need and still a pretty cheap starter gun
I remember when MRod Air had the M10s for dirt cheap once upon a time. To this day I still kick myself in the butt for not pulling the trigger. Duy here in the GRT currently has one of my RSII in .25, for a .257 conversion. Will start a post once I get it back. Going to finally pull the trigger this week, or maybe next, to start thinning the heard. Will start with a Travis tuned Kral Puncher breaker, maybe some Hatsans. Once the heard thins out, then the wife won't notice new additions ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
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M10 single shot had a lot of things going for it as a slug shooter. Still had the need for skinny slugs (.222ish) and the standard twist would work with slugs to about .415" length (weight would depend on shape). Would have been an easier conversion to a .224"faster twist barrel because of the thimble system(which wouldn't require an in-the-barrel o-ring).
Never had a chance to sit down side by side with a repeater type M10 ...somewhere in faulty memory, thinking they didn't change the M10 desgination for rhe first repeater versions...visually, there seems some differences that would hint at internal differences. Just never had the chance to do a side-by-side.
Will read the slug-posts,at least the ones that seem practical for a sporter type rifle, and dabble in it now and again,but just not really ready make one dedicated to fast twists and slug use.
If I do....would be a .224"barrel and likely a 1:9 or 1:10 twist....until that (if ever) happens, will just continue to adapt the slugs to the barrel rather than adapt the barrel to the slugs.
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this concept intrigues me. where would one get a barrel blank in this sizing and not break the bank? what would be a decent twist rate? the platform i would put this on is the .25 gauntlet. i think going to a smaller cal projectile would definitely increase fps for slugs. slug use would be the intended purpose here. the gauntlet has a 24" long barrel. So would the said barrel blank also need to be 24". this is all new to me and trying to absorb as much as i can so i'm within safe pressure limits. plus being able to still retain the .25 barrel for pellet use is a must. gauntlet barrel would be super easy to get machined. not much to them. neck down the barrel to fit receiver,cut 3 external o'ring grooves, and drill a transfer port opening. and taper the leade in the chamber. crown both ends and make a new probe.
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this concept intrigues me. where would one get a barrel blank in this sizing and not break the bank? what would be a decent twist rate? the platform i would put this on is the .25 gauntlet. i think going to a smaller cal projectile would definitely increase fps for slugs. slug use would be the intended purpose here. the gauntlet has a 24" long barrel. So would the said barrel blank also need to be 24". this is all new to me and trying to absorb as much as i can so i'm within safe pressure limits. plus being able to still retain the .25 barrel for pellet use is a must. gauntlet barrel would be super easy to get machined. not much to them. neck down the barrel to fit receiver,cut 3 external o'ring grooves, and drill a transfer port opening. and taper the leade in the chamber. crown both ends and make a new probe.
TJ Barrel liners. I believe they go by TJ Enterprises. The person to talk to is Todd. I’ve dealt with them via email. No problems at all.
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Here's one example, might actually be cheaper than TJs. https://www.lothar-walther.com/gun-barrel-blanks/rifle-barrels/standard-european/434/barrel-blank-twist-12.6.222rem/5-6x50mag/5-6x50rmag-od.39-l-29.72-cr-moly-steel?c=34 (https://www.lothar-walther.com/gun-barrel-blanks/rifle-barrels/standard-european/434/barrel-blank-twist-12.6.222rem/5-6x50mag/5-6x50rmag-od.39-l-29.72-cr-moly-steel?c=34)
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I never knew that LW had smaller diameter PB barrels available.... I looked through their "Standard European" blanks, which is where they are hiding (and in the Rimfire section), and found the following.... All are available for only $120 in CrMoly…. 8)
.224 cal 12" twist in 0.39" OD x 29.72" long, and 0.67" x 24.41" long.... (.223 Rem)
.224 cal 12.6" twist in 0.39" OD x 29.72" long, and 0.67" OD x 26.18" long.... (.222 Rem. 5.6mm)
.222 cal 15.4" twist in 0.39" OD x 29.72" long, also 0.47" OD x 25.79" long, and 0.67" OD x 24.41" long.... (.22 Hornet)
.221 cal 16.4" twist in 0.39" OD x 29.72" long, also 0.47" OD x 27.17" long, and 0.59" OD x 24.41" long, or 0.67" OD x 26.18" long.... (.22LR)
.224 cal 17.7" twist in 0.39" OD x 29.72" long, and 0.67" OD x 24.41" long, both $120.... (.22 Mag)
There are, of course, tons of barrels made in larger diameters (up to 1.5"), but they are very heavy, and a LOT more expensive.... The ones above do appear to be worth considering for airgun use.... You can get CF sleeves in many Metric IDs to match the diameters listed above.... I would definitely sleeve the 10mm (0.39") and 12mm (0.47") barrels.... The 15 mm (0.59") could also be used without sleeving…. and the 17 mm (0.67") I wouldn't bother sleeving, it is already pretty stout....
Bob
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I should have read a few more posts, the m10 (at least the one I have) is a single shot. My person preference is single shot only and I forget that everyone thinks they need a magazine fed bullet shooter. I wouldn't go faster than a 1:14 twist, it will stabilize a really long .22 round and is on the borderline of just being slightly to fast for the sub 40gr bullets out there.
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I think anything heavier than about 50 gr. you will need a 12" twist.... Don't forget that at the subsonic velocities we shoot, faster twist rates are necessary than what you use in a .223 PB at 3000+ fps.... According to the Kolbe twist calculator, the 14" twist is perfect for the 47 gr. 225420 Bowman by Arsenal....
Bob
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
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1:14 twist will stabilize 60gr bullets perfectly fine. Faster twist is never more accurate than a slower twist that is still adequate. If you want to shoot 60+ grain lead you will be better off going to .257
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
what if i go lighter than 47gr? will the twist still be ok? should i go with a slower twist rate? Or should i just make sure i can get my power level up to push them. Mind you that i'm basing this off a .25 gauntlet. 3000 psi bottle reglated to maybe 2000 or 2100 psi. hope it will be enough.
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
On what platform did you use for the 47 grain 225420 bullets?
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
On what platform did you use for the 47 grain 225420 bullets?
It's BSA Scorpion, mostly. Parts bin special. I.haven't shot lighter bullets much and the few I did were undersized thus not grouping that well.
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For even lower cost, if using cf tubing for stiffness and ultra light weight is somthing you enjoy, whre is a steal in liners!
I am using both 1-16 and 1-20 twist. the slower twist is a laser in both 29 and 39 grain slugs.
Ric, I have the same mold on order. Having it made up at .223 as cast. My barrels mic. at .2213.
I don't like shooting as cast. I always want to size down a bit which gives a more consistent and more perfectly round bullet resulting in better accuracy.
I wanted to order from Swede at NOE, but have been very frustrated as NOE has not listed them in a long time now. I finally ordered it from Arsenal. the 1-20 shots the decked version of the listed Arsenal slug very well indeed.
I shoot it in both the Raptor at .2213 and the PP 700 pistol at .216.
Here are the very well finished in the bore liners from Brownells gun smithing supply.
these are button rifled and have a very smooth bore.
www.brownells.com/aspx/search/default.aspx?cid=0&k=barrel%20liners&t=P&ksubmit=y (http://www.brownells.com/aspx/search/default.aspx?cid=0&k=barrel%20liners&t=P&ksubmit=y)
Knife/Mike
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only one is stock...definitely cheap and wouldn't be out much if it doesn't work as planned.
770-100-022WB
Brownells/Redman 1-16 Twist 25" Liner, .22LR rimfire. .310" od..Hmm now to find a carbon tube. this would certainly save some weight off the heavy gauntlet.
edit: might be over thinking this but....using the liner and machining a spacer adapter for the breech that has the leade in and transfer port cut in to mate up to the liner and extend down the liner a few inches beyond receiver. then put a carbon tube on, then an adapter/spacer on the muzzle end with a nut. similar to how fx does their barrels. then shroud the assemble so that it still looks stock and retains the air stripper and ldc inside. this would then be easy to swap barrels between 1:16 twist and 1:20 twist once its available or even any other barrel. just machine barrel ends to fit said receiver breech adapter. Would this not be basically a tension barrel setup? maybe even have to orings to keep barrel centered like fx does. or is the liner way to weak to handle this?
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Dan, if you are planning on using only 2000-2100 psi and a 26" barrel, I would not recommend you build around the idea of a 47 gr. slug.... IMO you will be doing a good job to reach 80 FPE at that pressure, which would be a 40 gr. slug at 950 fps.... In my .224 Hayabusa, which was unregulated with a 29" barrel and where the smallest port was 0.206" (almost bore area), at 2100 psi I was getting 960-970 fps (85 FPE) with a 41.3 gr. slug.... At 3000 psi, I could shoot the same slug at 1077 fps, and the 47 gr. Bowman at 1035 fps.... With it tuned down for a decent shot string, filling the 460 cc reservoir to 3000 psi, I could get 5 shots at 100 FPE or 7 shots at 90 FPE.... In a regulated PCP (29"barrel, bore size porting) with a 2800 psi setpoint I was right at 100 FPE with the 47 gr. slugs....
My point is that with a given barrel length the FPE will be pretty much proportional to the pressure.... If you are going to use 2000-2100 psi, I would stick to a slug of about 40 gr.... The NOE 225-39 (Lyman 225107) would be an excellent choice.... which would be fine in a 16-16.4" twist, and likely even OK in a 17.7-18" twist....
Bob
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Great info bob. Thanks. Was think more along the NOE 225-39 round as it was. Umarex USA just notified me today that they received my gauntlet. Sent in due to a bad dent in barrel about 4 inches from muzzle end. So just looking at all options depending on what they have to say about the barrel issue. Reading through this thread got me to thinking about a down size in caliber based on the .25 figuring the ,25 setup was pushing more than what a .22 cal one was. Plus slug options are more plentiful in .22 at moment.
Still very new to Pcp world and learning a lot. Read all the hard air magazine articles on Pcp tuning and tweaking. I have not had a chance to sit down and fully measure out the stock gauntlet internals. Need to once I get it back an make sure it shooting as it should. Then I figure I can plug in the numbers to see what I could possibly manage to squeeze out of the platform without messing too much with the .25 setup. Regulator pressure changes aren't too big a deal could go up or down fairly easily. Just mainly looking to be able to make reliable and accurate shots out to 100 or so yards. Currently couldn't get over 35 yards accurately with the bad barrel and y I sent it in for repair. Others manage 50+ with no issues.
Edit. Gauntlet has 24 inch oal barrel with port at 23 1/2 inches from muzzle iirc. So was planing to keep to a 24 inch barrel length.
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I'm never one to discourage a good project, but I don't think you'll be able to get that kind of power out of a Guantlet. Especially not a regulated one with the factory setup. You will need a big plenum to make that power regulated, so it will require some modifications in that department. Then there is the question of the valve in the gun being able to flow well enough(and the porting). Granted, I'm definitely not a Gauntlet expert, but I don't recall seeing any posts of them making anywhere close to the power levels being discussed. Maybe, some of the Gauntlet gurus will chime in on that. With what I know about them, you'd probably be best off just getting a good airgun barrel and sticking to pellets, or slugs that the barrel chosen is known to shoot somewhat consistently at lower power levels. I think a "What's the most power anyone has got out of a Gauntlet?" post would point you in the right direction, and tell you if those power levels are feasible. :)
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Rallyshark : this is y all this is being discussed. The .25 cal has a plenum volume of 25 c.c. Iirc. Not sure on port differences between it and the stock .22's. I know 1100 psi is stock on .22 whereas the .25 can handle 2100. The gauntlet will get the jsar super tune kit. Then a new probe to match the .223 cal barrel. If the stock lower tube won't handle or produce the power then a new tube and drop bottle block will be needed to help increase plenum size. My thought were with dropping caliber size would allow for more push on smaller caliber. Still more research on the port sizing differences between .22 and .25 stock gauntlets. They may very well have the same porting, in which case I could be chasing what isnt there. But for a .223 liner for $35 dollars and some other odds an ends I wouldn't lose much if it don't pan out.
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Rallyshark : this is y all this is being discussed. The .25 cal has a plenum volume of 25 c.c. Iirc. Not sure on port differences between it and the stock .22's. I know 1100 psi is stock on .22 whereas the .25 can handle 2100. The gauntlet will get the jsar super tune kit. Then a new probe to match the .223 cal barrel. If the stock lower tube won't handle or produce the power then a new tube and drop bottle block will be needed to help increase plenum size. My thought were with dropping caliber size would allow for more push on smaller caliber. Still more research on the port sizing differences between .22 and .25 stock gauntlets. They may very well have the same porting, in which case I could be chasing what isnt there. But for a .223 liner for $35 dollars and some other odds an ends I wouldn't lose much if it don't pan out.
That's very true about the liner, so not a huge loss if it doesn't work out :) I don't know enough about the Gauntlet to say whether it would work or not, but I do know you'll definitely need more plenum to work with. You generally want to get as close to 1cc per fpe as you can, but upping the set point can overcome the plenum size a little(learned that one from Bob :D ) . As long as there is enough material and room, ports can always be opened up more, so that would help. Porting will need to be close to bore size I think.
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Very tru. Hence the reason for caliber down grade. I'm pretty sure ports should be a touch bigger in .25 cal I'm hoping versus the .22. which makes the .223 option a maybe. I'm thinking of trying to set the .223 barrel up to fit like an fx barrel. Basically a slightly tensioned barrel setup. Especially since is such a small od liner, and not a full barrel.
Edit: jsb 25.39 hit 45 fpe in stock form at 1900.
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Very tru. Hence the reason for caliber down grade. I'm pretty sure ports should be a touch bigger in .25 cal I'm hoping versus the .22. which makes the .223 option a maybe. I'm thinking of trying to set the .223 barrel up to fit like an fx barrel. Basically a slightly tensioned barrel setup. Especially since is such a small od liner, and not a full barrel.
Edit: jsb 25.39 hit 45 fpe in stock form at 1900.
If you want to avoid tinkering tuning and headaches, then CF tube sleeving that small liner is the "play it safe" way to go.
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Yep! Exactly the way I went. ;)
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Im not very familiar with the gauntlet, but from what has been said I dont think it will be a realistic option for you unless you can run it unregulated.
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If i could manage to get close to 70 FPE with the combo i'd be happy. I know that in modded form the gauntlet has been able to push 65 FPE with mods in .25 cal. The biggest increase is changing out the poppet in the vale which will allow it to breathe way better. That is part of what the JSAR super tune kit give.
RKR & Knifemaker. I do plan to sleeve the liner.
Knife did you make a tight fitting sleeve to liner, or is their air gap between sleeve and liner?
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If i could manage to get close to 70 FPE with the combo i'd be happy. I know that in modded form the gauntlet has been able to push 65 FPE with mods in .25 cal. The biggest increase is changing out the poppet in the vale which will allow it to breathe way better. That is part of what the JSAR super tune kit give.
RKR & Knifemaker. I do plan to sleeve the liner.
Knife did you make a tight fitting sleeve to liner, or is their air gap between sleeve and liner?
You use epoxy to attach the CF tube to the liner. If needed you can use two CF tubes to increase the diameter even further. If you can make 65 fpe with pellets you should do more with bullets, my .25 BSA was tuned for 60 fpe and I used the same basic valve system for the .224 and achieved 100 fpe - although with 5.5" longer barrel.
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thanks RKR. so my thought was to make a spacer to fit the breech come out an inch or so beyond the receiver have the o'ring slot cut and transfer hole ( basically same as factory barrel end), then bore the adapter to allow liner to sit just before barrel port. Spacer beyond the receiver sized to say 10mm. i think barrel liner is .310" (7.8 mm +/-) make a spacer/ air stripper for the muzzle end (also 10mm, but larger and ported to allow for shroud). glue 10mm od x 8mm id tube over barrel, then a 15mm od x 10mm tube over this to attach barrel to spacers and flush everything smooth. Then the factory shroud could be placed over it all. i'll try to draw a pic of this.
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I would probably make a thimble for o-rings and TP and then just do a leade in the barrel breech end and sleeve it to fit the breech.
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barrel liner is green. black outer would be shroud. yellow is inner carbon fiber core bonded to barrel. red on left is breech adapter. red on right is air stripper adapter. middle black is outer carbon core locked to adapters and inner carbon tube.
would be nice to be able to change the liner out in this assembly......
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Just because a gun will make 65 FPE in .25 cal does not mean you can reach that in .22 cal, that is a common misconception.... In fact more likely you will drop down to about 55-60 FPE, depending on the port size.... When comparing maximum possible power with the same barrel length and pressure, and with bore-area porting, a .224 cal would only give about 80% of the FPE of a wide open .25 cal.... The FPE is directly related to the bore area, which for a given pressure determines the force available to launch the slug....
Bob
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Just because a gun will make 65 FPE in .25 cal does not mean you can reach that in .22 cal, that is a common misconception.... In fact more likely you will drop down to about 55-60 FPE, depending on the port size.... When comparing maximum possible power with the same barrel length and pressure, and with bore-area porting, a .224 cal would only give about 80% of the FPE of a wide open .25 cal.... The FPE is directly related to the bore area, which for a given pressure determines the force available to launch the slug....
Bob
Pellet guns usually have 75-80% max port size while bullet shooters use 100% port size. That more than makes up the difference. In my example the .25 had 4.5 mm ports while the .224 had 5.5 mm ports.
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Absolutely, but you are then talking apples and oranges.... Had you done the same mods to your .25 cal, you would have been well over 100 FPE....
My comment was directed at the idea that a 65 FPE Gauntlet .25 cal should be able to get 70+ FPE in a smaller caliber.... Maybe it can, but not without extensive other changes....
Bob
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Just because a gun will make 65 FPE in .25 cal does not mean you can reach that in .22 cal, that is a common misconception.... In fact more likely you will drop down to about 55-60 FPE, depending on the port size.... When comparing maximum possible power with the same barrel length and pressure, and with bore-area porting, a .224 cal would only give about 80% of the FPE of a wide open .25 cal.... The FPE is directly related to the bore area, which for a given pressure determines the force available to launch the slug....
Bob
That is true. The limitation being "with the same barrel length".
FPE is force x distance.
Maximum FPE is then psi x barrel_volume. For an equal slug+air mass, the .22 would need about a 30% longer barrel in order to have the same velocity and FPE as the .25 caliber.
Since the acceleration down the barrel is lower for the .22, we'd also need a 30% longer dwell in the valve.
Up until now, all my PCP work has been to design for either 12fpe or 20fpe in .177 caliber.
I'm currently working on my .22 benchrest gun design, with no rule constraints on FPE, so I'm following threads like this.
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Absolutely correct, since the force is bore area times pressure, and the FPE is that force times barrel length, you can simplify that to pressure times barrel volume (making sure you correct the units)…. The maximum FPE is give by....
FPE = Pressure (psi) x Barrel Volume (cu.in) / 12
However that requires constant pressure (hence infinite volume), no friction, and no allowance for the mass of the air.... Very few PCPs meet even 50% of that, so a good "lofty goal" is given by....
FPE goal = pressure x barrel volume / 24
Bob
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ok. so then i would need to increase the barrel length to maintain or achieve the 65 fpe. hmmm. the next longest liner is 32" , but that one is $95.55 three times more in price over the 25" liner. so i'm guessing that with the 24" as they say the liners do need to be trimmed down, that i would be hard pressed to attain the 65 fpe. without really upping the pressure. No one is truly sure what the stock tube will handle, but sure the small plenum available is also a limiting factor. So it would look like the lower tube would need to be swapped out for a tube of a know mswp and adding in more plenum volume.
edit:getting a liner at that price would be a no go. so it would be back to a full euro LW barrel. as they are $120+ s/h. by the time the carbon tubes and adapters are made for the liner it would be over the price of getting a blank barrel and having it machine to fit breech.
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I don't know how big the plenum is in a Gauntlet, but for an 80 FPE gun you would like 80 cc, but can get away with half that (40cc) if you increase the pressure about 10%.... It may well be that the Gauntlet is a poor choice for this project.... unless you build it to shoot lighter slugs, like 25-30 gr....
Bob
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I'm just about thinking you are.correct bob. Currently I believe the gauntlet has 20-25 cc plenum. Which probably accounts for y it has a 1900 regulator set point from factory. Guess I'm gonna have to wait for my gauntlet to get back from factory service to see what I end up with. If the accuracy issue isn't fixed I'll definitely be looking for a new barrel for it. Would be nice if I could get slugs running it, as well as pellets. But may be hoping for too much from the platform. I did try avs slugs. But due to barrel issues they kinda worked. But I'm learning g that even though they were pure lead they needed to be sized down. They were .254. I should have .249's as the barrel measures out as .248.
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I don't know how big the plenum is in a Gauntlet, but for an 80 FPE gun you would like 80 cc, but can get away with half that (40cc) if you increase the pressure about 10%.... It may well be that the Gauntlet is a poor choice for this project.... unless you build it to shoot lighter slugs, like 25-30 gr....
Bob
My upcoming benchrest project is a .22 Armada (Marauder based). The plan is to get as much as I can in stock form, running at 3000psi. Shooting 18.1gr and maybe 25.4gr pellets. Then add a 450cc 4500psi bottle, regulated to 3000psi, with a 200cc plenum, then some valve work, and finally a 27.5" long tensioned liner in a CF shroud. The goal is to shoot 25gr pellets up to 60fpe. My ultimate goal for airguns using current technology is to shoot 40gr slugs at 1060fps (same as a standard velocity .22LR).
Maybe using a barrel like this:
https://www.cparifles.com/products/douglas-22lr-caliber-barrel-blank-1-in-16-twist-29-5-long?variant=7579203909 (https://www.cparifles.com/products/douglas-22lr-caliber-barrel-blank-1-in-16-twist-29-5-long?variant=7579203909)
I have a mold to make 40gr 22LR, and 25gr 22short bullets. I could modify the mold slightly to make it more suited to slug use (no cartridge):
(http://www.scotthull.us/photos/Misc/22LR-SLUG-00.JPG)
(http://www.scotthull.us/photos/Misc/22LR-SLUG-01.JPG)
(http://www.scotthull.us/photos/Misc/22LR-SLUG-02.JPG)
(http://www.scotthull.us/photos/Misc/22LR-SLUG-03.JPG)
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Not a pro here by any means, but you goal seems attainable. I have a Jkhan .22 that I ported to .201 and 24 grain swagged will hit 1000 FPS @ 3k psi. Also have an ace precision .22 that at 2400 psi shoots the huben cast 35.4 @ 940. No clue what it will hit at 3k psi, so a 70 ft lb .224 should work on the armada. Plus the .224 has a nice bc. An after market valve and porting should get you there. I’m running an older war valve in mine(.25)
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First time I have seen a mould for CB (conical ball) .22 rimfire ammo....
It is certainly possible to duplicate the performance of a .22LR target load, my .224 Hayabusa does that at 3000 psi.... 1077 fps with a 41.3 gr. swaged RWS bullet....
(https://i378.photobucket.com/albums/oo221/rsterne/224%20Long%20Range%20PCP/224cal41_5gr.jpg) (https://s378.photobucket.com/user/rsterne/media/224%20Long%20Range%20PCP/224cal41_5gr.jpg.html)
That setup is used a lot, tethered at 3000 psi, in the Netherlands for 100m benchrest…. This 17mm group at 100 metres is not untypical of their results....
(https://i378.photobucket.com/albums/oo221/rsterne/224%20Long%20Range%20PCP/17mm_at100M_DrummenSinner223.jpg) (https://s378.photobucket.com/user/rsterne/media/224%20Long%20Range%20PCP/17mm_at100M_DrummenSinner223.jpg.html)
They most often use a 15" twist Hornet barrel....
Bob
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BOb...got some more numbers:
stock gauntlet in .22 (14.3 grain) lead pellets, achieving 60 shots, 900 fps, at 1100 psi. 25.89 FPE
stock gauntlet in .25 (24.35 gr) lead pellets, achieving 24 shots, 890 fps, at 1900 psi. 45 FPE
both as far as i can determine have the same barrel length at 24"
i know there are formulas out there to figure this out, but can find it for some reason. i know with the barrel swap i don't expect to get the 60 shots off 13 cu. in. bottle filled to 3000 psi. If i could be 30 shots( 3 x 10 shot mags) would be nice. What would my power look like?
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I think I got it now.
.224______________
Barrel volume is 8.921238137 @ 24"
A= .371718255
F= 780.6083355
P= 1,561.216671
.25_______________
Barrel volume is 9.424777961 @ 24"
A= .392699081
F= 824.6680716
P= 1,649.336143
.224 port sizes
.156 =57.63
.172 =63.55
.188 =69.46
.203 =75
.25 port sizes
.156 =64.32
.172 =70.92
.188 =77.52
.203 =83.70
.25 using 1100 psi to shoot 24 shots @45 fpe is 1,080 fpe. Giving 1.0944 fpe/ci.
So my guess is the stock gauntlet has wicked small porting probably. Due to low fpe. Or is there just that much loss in the system. Once mine is back. I'll be looking at the port sizes for a more accurate picture.
Bob how did you make the drop block on your 6mm? It looks like it may be a 2 piece setup? If I increase my plenum using a new lower tube, that would be cool to turn the bottle around to give it better rearward balance.
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First time I have seen a mould for CB (conical ball) .22 rimfire ammo....
It is certainly possible to duplicate the performance of a .22LR target load, my .224 Hayabusa does that at 3000 psi.... 1077 fps with a 41.3 gr. swaged RWS bullet....
...
They most often use a 15" twist Hornet barrel....
Bob
For the first barrel I'm making to replace the factory Crossman .22 barrel, I have an FX 700mm x .22 airgun liner with a 1:15 twist.
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Tank block is made in one piece....
(https://i378.photobucket.com/albums/oo221/rsterne/6mm%20Sporter/Tank%20Block%20Rear_zpscwzynwit.jpg) (https://s378.photobucket.com/user/rsterne/media/6mm%20Sporter/Tank%20Block%20Rear_zpscwzynwit.jpg.html)
Scott, that should be a good choice for a barrel, but you will likely need to size your slugs....
Bob
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First time I have seen a mould for CB (conical ball) .22 rimfire ammo....
It is certainly possible to duplicate the performance of a .22LR target load, my .224 Hayabusa does that at 3000 psi.... 1077 fps with a 41.3 gr. swaged RWS bullet....
...
They most often use a 15" twist Hornet barrel....
Bob
For the first barrel I'm making to replace the factory Crossman .22 barrel, I have an FX 700mm x .22 airgun liner with a 1:15 twist.
I just got through building a barrel off a 700mm slug liner. It will most certainly help in the power department, and the weight will be low too ;)
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Bob that is a Beautiful piece you made. What aluminium spec was used on that?
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6061-T6.... Mounting it offset far enough in the 4-jaw to turn the spigot that fits into the tube was a bit "hairy".... definitely some pucker factor there, especially when you start....
Bob
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Scott Did you make that mold? That’s a beautiful mould! I want one.
Dan. if I remember correctly. The gauntlet 25 cal can get up to 95fpe. I haven’t done it myself but SouthernGunner has. And it doesn’t look like he added plenums. So it’s actually 24cc for the gauntlet. I don’t know how many shots he can get off at 95fpe. Or what mods he has done to get there.
I have built a .224 regulated marauder with 80cc plenum. The highest I have tested it to was 1009fps with 39grain slugs at 2700 psi. It has a Cothran valve and super strong hammer springs so its consuming air like no other.
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Duy; That's insane...95 FPE with the gauntlet. thanks for the plenum size. i was sure i read it being 25cc. gonna have to ask what souther gunner did to it.
Bob; reading you articles and doing some calculations. Barrel volume is tripping me up. (c2xPi/4xL )=V barrel volume in cubic inches.
that gives me 9.424777961 for 24" .25 barrel. and 9.47881552 for 25.5" .224 barrel. in you article you mention that a 48".25 barrel is 30cc, as well as a 12" .50 barrel, using 3000psi. How did you figure the cc's out?
so if my math is correct:
using .156 ports at 1900 psi with 24" barrel
.25 cal would get 58.60 FPE
.224 cal would get 52.15 FPE but at 2100 psi its 57.63 FPE
granted theses are theoretical numbers, but just trying to get a better understanding and make sure my numbers are on track.
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1 CI = 16.4 cc.... Do yourself a favour and don't use so many decimal points.... I don't know where you got your volumes from, 1.18 CI for the 24" .25 cal, and 1.00 CI for the 25.5" .224 cal, are the volumes in CI....
A 48" long .25 cal barrel is 2.36 CI, which is 38.6 cc (don't know where the 30 cc came from)…. and a 12" long .50 cal barrel is exactly the same volume....
Your FPE numbers look OK.... Remember, that method (multiplying the caliber by the smallest port size and then by PI/4) is only for predicting the maximum FPE, and it's only an approximation.... You can multiply that result by the pressure and then by the barrel length / 24 to find your "lofty goal".... Remember, that is almost never achieved, even for a single, maximum power shot.... I have only approached within about 10% of that goal, at a velocity of 950 fps (pellet weight is 1/2 the FPE)…. If you use a heavy pellet at lower velocity, it is easier.... However, once you drop down to a realistic tune (so it's not an air hog), you won't achieve that goal....
Bob
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very true, BOB. yes my numbers were in CI.
i got the 30CC from the article you put out. just before the end out this https://hardairmagazine.com/ham-columns/how-to-obtain-the-maximum-power-from-a-pcp-air-rifle/ (https://hardairmagazine.com/ham-columns/how-to-obtain-the-maximum-power-from-a-pcp-air-rifle/). last picture in it.
one last thing. (i hope, lol) is there a way to figure out barrel length?
basically, a 24" .25 cal barrel is 1.18 ci (19.3 cc) using its barrel volume, what would the formulae be to figure out how long a .224 barrel should be to match as closely as possible the .25 cal volume?
MAybe i messed up the barrel volume calculation V=(C2xPI/4xL) v= volume in cu in.
.25 squared x 3.14 / 4 x 24 =
.5 x 3.14 / 4 x 24 =
1.57 / 4 x 24 =
0.3925 x 24 =
9.42
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Scott Did you make that mold? That’s a beautiful mould! I want one.
Dan. if I remember correctly. The gauntlet 25 cal can get up to 95fpe. I haven’t done it myself but SouthernGunner has. And it doesn’t look like he added plenums. So it’s actually 24cc for the gauntlet. I don’t know how many shots he can get off at 95fpe. Or what mods he has done to get there.
I have built a .224 regulated marauder with 80cc plenum. The highest I have tested it to was 1009fps with 39grain slugs at 2700 psi. It has a Cothran valve and super strong hammer springs so its consuming air like no other.
I did not make the mold. And I have not tested these bullets in an airgun. They are designed to fit in a 22lr case. Yhey may not be optimal for an airgun. The middle of the body is .222" OD and the tail is .200" OD.
http://22lrreloader.com/design-details/ (http://22lrreloader.com/design-details/)
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The 30 cc was a goof.... :-[ …. I started talking about a .22 cal, 24" which was 15 cc, then I changed horses mid stream for the comparison between .25 cal and .50 cal and forgot to change the caption.... Me bad !!!
.25 squared is 0.0625, not 0.5.... ;) …. That makes us even, no?.... ;D
To get the same barrel volume in a .224 cal as a 24" barrel in .25 cal you would take 24" x (.25^2 / .224^2) = 29.9"....
Bob
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.... Remember, that method (multiplying the caliber by the smallest port size and then by PI/4) is only for predicting the maximum FPE, and it's only an approximation....
Some more to think about:
Port area directly affects power, not energy. If you cut the port area in half, you can get the same FPE by increasing the pellet mass by 16x (assuming sufficient valve dwell , 4x).
For any given pressure:
Port_area determines maximum power (horsepower, ft-lb/s, KW, etc.). Barrel_volume determines FPE (energy, ft-lb). Knowing power, you need a time multiple in order to determine FPE. For any given power, a heavy projectile takes more time to move down the barrel. More time gives more FPE.
A full port .22 caliber at 3000psi can produce about 280 horsepower. A 0.11" diameter port will produce about 70 horsepower. (assuming 100% efficiency).
A .22 caliber with a .11" diameter port should shoot a 160gr projectile with about the the same FPE as a full port .22 with a 10gr projectile.
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While that analysis may be correct, my "lofty goal" formula is intended to give some indication of what the maximum FPE you might expect when the projectile is moving at 950 fps (and hence FPE = twice the projectile weight in grains)…. The correlation to transfer port size (and hence flow rate) was only to give a rough idea of how it affects "normal" PCP operation, again with that velocity in mind....
At the limit, the maximum possible FPE is still dependent on bore volume and pressure.... The percentage of that you can achieve will depend on the ratio of projectile mass to the air mass (and other losses).... For a given barrel length and pressure, the air mass is approximately constant (though the length of time to move that mass through the port may vary with projectile mass)…. For a 24" barrel of .224 cal, full of air at 3000 psi, that is about 57 gr.... So, in fact, a 160 gr. projectile should end up with significantly more FPE than a 10 gr. one, in the real world.... How that works out if the 160 gr. projectile is operating with a 0.11" port at 3000 psi in a .22 cal, 24" barrel is beyond my ability to calculate.... and so far away from what I might actually try and build, is beyond my interest as well....
Bob
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The 30 cc was a goof.... :-[ …. I started talking about a .22 cal, 24" which was 15 cc, then I changed horses mid stream for the comparison between .25 cal and .50 cal and forgot to change the caption.... Me bad !!!
.25 squared is 0.0625, not 0.5.... ;) …. That makes us even, no?.... ;D
To get the same barrel volume in a .224 cal as a 24" barrel in .25 cal you would take 24" x (.25^2 / .224^2) = 29.9"....
Bob
Got it now Bob. No harm no foul. Plus I was using square root vs square. Numbers look way better now. Lol
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".... Remember, that method (multiplying the caliber by the smallest port size and then by PI/4) is only for predicting the maximum FPE, and it's only an approximation...."
...formula is intended to give some indication of what the maximum FPE you might expect when the projectile is moving at 950 fps...
OK - for a constant (or relatively constant) velocity (950fps in your case), that is true.
Each of these gets total FPE:
FPE = pressure x barrel_volume (this is NOT affected by port size or pellet mass)
FPE = mass_flow_rate x time (this is affected by port size and pellet mass)
Typically, my design parameters are based on desired projectile and desired velocity. With that I can design (on paper/computer) what is needed to achieve that before actually building it.
It works well with PCP powerplants.
I tried it with piston guns but it is more complicated.
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Scott, please forgive my post above, I did not mean to sound condescending.... Chalk it up to being tired.... You obviously have spent a fair amount of time working out a formula for horsepower based on port area, and the relationship to projectile weight.... We know from empirical data that the FPE is roughly proportional to the smallest port diameter (not area)…. but this should be applied at about 950 fps (ie constant velocity)…. If the velocity is constant, then the projectile weight must be proportional to the FPE, and at 950 fps, it would be 1/2 gr. per FPE.... Further, if the pressure, barrel length and caliber are all constant, then the average velocity, and hence the acceleration, must be virtually constant as well.... and since we are talking about a maximum power shot, the valve is open until the projectile leaves the barrel.... For simplicity, let us assume an infinite reservoir, so constant pressure at the valve seat....
You state that the horsepower is proportional to the port area, which is the square of the diameter.... If the air is accelerating a projectile whose weight is proportional to the port diameter, can you mathematically prove that the muzzle velocity should remain a constant?.... If you can do that, then we have our answer as to why the FPE is proportional to the port diameter, rather than the port area.... ie the math to back up the observations....
Bob
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Awesome. thanks for helping get this straight Bob. Spreadsheet looks way better now. And i reduced the decimals.
Scotchmo
FPE = mass_flow_rate x time (this is affected by port size and pellet mass)
do you have a formula for your findings with this?
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Awesome. thanks for helping get this straight Bob. Spreadsheet looks way better now. And i reduced the decimals.
Scotchmo
FPE = mass_flow_rate x time (this is affected by port size and pellet mass)
do you have a formula for your findings with this?
That's a poor example on my part. It's not "findings". This is all at a preset pressure. Maybe I should have said "proportional to" and not "=".
Knowing the pressure, you can find the density of the HPA. If you know the mass flow rate, and the density of the HPA, you can calculate the volumetric flow rate. Knowing the volumetric flow rate and pressure, you get power:
http://www.metaris.com/hp-calculator.php (http://www.metaris.com/hp-calculator.php)
Multiply power x time and you get energy, which should translate into kinetic energy of the pellet+air.
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Scott, please forgive my post above, I did not mean to sound condescending.... Chalk it up to being tired.... You obviously have spent a fair amount of time working out a formula for horsepower based on port area, and the relationship to projectile weight.... We know from empirical data that the FPE is roughly proportional to the smallest port diameter (not area)…. but this should be applied at about 950 fps (ie constant velocity)…. If the velocity is constant, then the projectile weight must be proportional to the FPE, and at 950 fps, it would be 1/2 gr. per FPE.... Further, if the pressure, barrel length and caliber are all constant, then the average velocity, and hence the acceleration, must be virtually constant as well.... and since we are talking about a maximum power shot, the valve is open until the projectile leaves the barrel.... For simplicity, let us assume an infinite reservoir, so constant pressure at the valve seat....
You state that the horsepower is proportional to the port area, which is the square of the diameter.... If the air is accelerating a projectile whose weight is proportional to the port diameter, can you mathematically prove that the muzzle velocity should remain a constant?.... If you can do that, then we have our answer as to why the FPE is proportional to the port diameter, rather than the port area.... ie the math to back up the observations....
Bob
".... Further, if the pressure, barrel length and caliber are all constant, then the average velocity, and hence the acceleration, must be virtually constant as well...."
That is only true for instance A (full port). There will be a big difference between the acceleration profiles of instance A (full port) and instance B (0.11” port).
Instance A will have a fairly constant acceleration as the slug moves down the barrel. Instance B will have a higher initial acceleration, which will remain constant only up to the choke point, and then acceleration will start to fall and then continue to fall after that.
When using the constant velocity of 950fpe, I don't know if there is a single/simple equation to show why the projectile energy (FPE) is ending up proportional to port diameter. My first guess why is because the air mass proportions are skewing it toward that result. I plan on adding a variable port restriction into my dump gun spreadsheet model and running some simulations.
The flow through the restriction (orifice) will be assumed (modeled) as a friction-less nozzle, where in practice it's not. There would need to be a flow coefficient in order to get closer to real world results. It's the difference between a transfer port that is a simple orifice and a transfer port with a perfectly tapering inlet and outlet.
A couple years back, Lloyd ran some experiments in trying to maximize the supersonic projectile velocity in a PCP airgun. My spreadsheet model seemed to match up fairly well with those results. Now that I'll be trying to maximize the projectile FPE, near sonic velocities, in a ported gun, the same choked flow constraints will apply. So I have a renewed interest.
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The average acceleration must be the same, if the barrel length and MV is the same, no? (eg. 950 fps over 24").... Yes, the profile might be different, although if the port is half the diameter and the pellet half the weight, even that might not be too different.... although I would still expect more acceleration initially and less towards the muzzle with the smaller port.... After all, initially there is very little mass flow, because the pellet is stationary or barely moving, so the pressure governs, and the lighter pellet would therefore see higher acceleration.... Choking may occur as the pellet approaches the muzzle, but as you know, it is almost impossible to predict or model.... Most attempts to include choking end up predicting too little force/acceleration and a lower than observed velocity/energy.... This is likely due to a lot of the latter stages of acceleration being the result of the expansion of the air in the barrel, rather than new air being added through the (restricted) port.... I am convinced that no choking occurs with bore-area porting and a dump shot (dwell greater than shot duration), with the MV being subsonic.... or even low supersonic, because of the elevated SoS at high pressures....
I'm sure the FPE being proportional to the port diameter is not 100% accurate.... but it does seem to be a fair estimate, even though I don't have the math to say why.... I wish you better luck.... Perhaps a new thread in the Workshop, rather than hijacking this one further?....
Bob
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1 in 7" twist 25" long .223 GM blank for $58:
http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/ (http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/)
Fast enough twist to shoot this BBT:
(http://noebulletmolds.com/photos/albums/224-75-FN-BT-/N.O.E._Bullet_Moulds_224-75-FN_-BT-__75_gr_Sketch.Jpg)
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1 in 7" twist 25" long .223 GM blank for $58:
http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/ (http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/)
Fast enough twist to shoot this BBT:
(http://noebulletmolds.com/photos/albums/224-75-FN-BT-/N.O.E._Bullet_Moulds_224-75-FN_-BT-__75_gr_Sketch.Jpg)
When you stick that barrel to a gun with 2900 psi max fill pressure, how fast will that bullet go?
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1 in 7" twist 25" long .223 GM blank for $58:
http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/ (http://www.gmriflebarrel.com/557-blank-5-56-mm-223-caliber-25-x-1-062-1-7-gunsmith-edition-raw-blank/)
Fast enough twist to shoot this BBT:
(http://noebulletmolds.com/photos/albums/224-75-FN-BT-/N.O.E._Bullet_Moulds_224-75-FN_-BT-__75_gr_Sketch.Jpg)
When you stick that barrel to a gun with 2900 psi max fill pressure, how fast will that bullet go?
It needs 3800 PSI minimum to get 950 FPS:
https://www.gatewaytoairguns.org/GTA/index.php?topic=156052.msg155724522#msg155724522 (https://www.gatewaytoairguns.org/GTA/index.php?topic=156052.msg155724522#msg155724522)
So if a 2900 PSI max fill gun is regulated at say 2500 PSI velocity will be much lower.
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There are not that many guns that can take 3800 psi fills (especially reasonably priced ones) so that 75 grain bullet is not very practical. You can make 950 fps with 2800 psi, 24" barrel and 225420 47 grain bullets. I actually got 980 fps so 950 fps should be doable with bullets in the low/mid 50 grain weights. Add barrel length and even 60 grains starts getting useful.
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How about this idea as a .224 or .223 slug slinger...... a Seneca Recluse conversion? It’s single shot so it could allow for longer bullets and if I recall correctly, it will allow for a longer barrel without looking too awkward since it currently has a 24” barrel. It’s a *(&^ if a rig and has the double tubes. Any ideas?
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Rebarreling a bigbore to smaller caliber is the easiest way to make a .224 or .257 bullet shooter. Recluse would work but the trigger is not the greatest. Evanix/Winchester .357 and .45 guns are good candidates with rather long magazines and enough power. Kral guns can be modded for power but magazine is short. Evanix AR6 would be a very nice candidate with long magazine if it wasn't for the trigger. With enough work most any gun can be made to shoot 40-50 grain .224 slugs, single shot ones being easiest to convert.
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I hoe to be testing the .222 barrel in the Mini Raptor again as soon as the weather permits and I get the valve back to optimum.
It was at 75 fpe before I switched to the .257 barrel which gave 87 fpe.
After a little maintenance, the .257 barrel went 106 fpe with no increase in HS Or Reg Pressure.
It will be interesting to see where the .222 barrel is now with no other changes other than the barrel swap. ;)
Knife
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There are not that many guns that can take 3800 psi fills (especially reasonably priced ones) so that 75 grain bullet is not very practical. You can make 950 fps with 2800 psi, 24" barrel and 225420 47 grain bullets. I actually got 980 fps so 950 fps should be doable with bullets in the low/mid 50 grain weights. Add barrel length and even 60 grains starts getting useful.
Do you have a picture of your 225420 47 grain bullet?
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There are not that many guns that can take 3800 psi fills (especially reasonably priced ones) so that 75 grain bullet is not very practical. You can make 950 fps with 2800 psi, 24" barrel and 225420 47 grain bullets. I actually got 980 fps so 950 fps should be doable with bullets in the low/mid 50 grain weights. Add barrel length and even 60 grains starts getting useful.
Do you have a picture of your 225420 47 grain bullet?
(http://arsenalmolds.com/image/cache/catalog/224%20Bob%20Sterne-500x500.JPG)
http://arsenalmolds.com/bullet-molds?product_id=165 (http://arsenalmolds.com/bullet-molds?product_id=165)
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
Hi RKR
Do you think that 12.6 twist and 47 grains is a better solution then 15 twist horney barrel and rws 41.5 grains?
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I think I'm leaning towards this barrel mated to my .25 gauntlet.
Barrel Blank - Twist:12.6" | .222Rem/5,6x50Mag/5,6x50RMag | OD:.67" | L:26.18" | Cr-Moly Steel"
.219 bore
.224 groove
Is this twist going to be ok?
I've been using that twist succesfully with 47 grain 225420 bullets. 24" version is enough for 980 fps.
Hi RKR
Do you think that 12.6 twist and 47 grains is a better solution then 15 twist horney barrel and rws 41.5 grains?
It has better BC and thus it will have less wind drift at long distance which usually means smaller groups in real life shooting. It will also carry more energy assuming same velocity. The downside is that it will not fit in most magazines, I believe Evanix AR6 and long magazine .45/.357 Evanix/Winchester guns can be modded to use that bullet. JSAR Raptor and Sumatra are also likely candidates.
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I just received an e mail that I should have this mold by Friday.
I have been testing bullets that are from the same mold, but decked to throw them at 29 grs for use in the PP 700 pcp pistol.
It is very accurate in the little pistol, adn quite accurate in the Mini Raptor as well.
It gets 1036 fps for 92.73 fpe in the Mini Raptor in its .257 version. I am anxious to see the results in the .222 as well. the .22 version decked to 29 grs hit 75 fpe in the .222.
I will order a second one for decking as I plan to use the mold at full size for the Mini.
Knife
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Maybe in the future a .223 Raptor will be added to the heard. From what it looks like, everyone and their grandmas are trying to unload their PCPs, most likely to collect enough bubble gum money for a Raptor. Hence, the lower than expected resale value of ones’ beloved AGs. Knife, have you tried the .224 Northamericanarms bullet in your .223 Raptor? If you’d like, I’ll send you some from my pile for you to try out. N/C. Just curious to see how they would do.
I appreciate it! I do have some on hand. If it will ever stop poring down rain, I will test them in this new barrel. ;)
Hello Knife! Was wondering if you had a chance to test the NAA 30 grainers in your Raptor?
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That Rifle looks good Ric!
Tofazfou and I discussed and played with the idea of a .224 years ago. He and i went in different directions. While both went with the .257, I still want to go .22. Tof. Went with the 172 HmAir, and man, what a shooter it is!
I've long been a proponent of the North American Arms black powder .22 bullets. It's a deal that can't be beat! ;)
Knife
Sadly, in testing the NNA bulelts, I learned that they are VERY hard and do not shot nearly as well as any of my cast slugs.
I have found that the 1-20 twist out shots the 1-16 twist by a good margin. 1-16" gave me apx. 4-5 inch groups at 80 yards. The 1-20" is giving me 1" with the worst slug, and 1/2" with the best two. slugs.
The barrel JSAR sent for testing is a .250 with a 1-22 twist. Looking forward to the testing with quite an assortment of both swagged and cast slugs.
Just as soon as the new valve arrives, the test will begin. ;)
Mike/Knife
Knife
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Maybe in the future a .223 Raptor will be added to the heard. From what it looks like, everyone and their grandmas are trying to unload their PCPs, most likely to collect enough bubble gum money for a Raptor. Hence, the lower than expected resale value of ones’ beloved AGs. Knife, have you tried the .224 Northamericanarms bullet in your .223 Raptor? If you’d like, I’ll send you some from my pile for you to try out. N/C. Just curious to see how they would do.
I appreciate it! I do have some on hand. If it will ever stop poring down rain, I will test them in this new barrel. ;)
Hello Knife! Was wondering if you had a chance to test the NAA 30 grainers in your Raptor?
Yes I did. Very hard, shoots terrible! Even when properly sized.
I received the new arsenal mold and decked it to 31.8 grs. man it is a shooter. I had the reg set to 2700 (usually at 3000) and it hit 1010 fps for a very accurate combination!
I will be testing them full length as well shortly.
Mike
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Maybe in the future a .223 Raptor will be added to the heard. From what it looks like, everyone and their grandmas are trying to unload their PCPs, most likely to collect enough bubble gum money for a Raptor. Hence, the lower than expected resale value of ones’ beloved AGs. Knife, have you tried the .224 Northamericanarms bullet in your .223 Raptor? If you’d like, I’ll send you some from my pile for you to try out. N/C. Just curious to see how they would do.
I appreciate it! I do have some on hand. If it will ever stop poring down rain, I will test them in this new barrel. ;)
Hello Knife! Was wondering if you had a chance to test the NAA 30 grainers in your Raptor?
Yes I did. Very hard, shoots terrible! Even when properly sized.
I received the new arsenal mold and decked it to 31.8 grs. man it is a shooter. I had the reg set to 2700 (usually at 3000) and it hit 1010 fps for a very accurate combination!
I will be testing them full length as well shortly.
Mike
You're talking about 225420 mold? What barrel were you using? Looking forward for the results with full length bullets, they were fine in my 12.7" twist LW barrel at around 950 fps.
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Ric, Y
Yes I will be testing the full length as I saved a few before decking the mold.
the longer full length like a fast twist. However, the shorter slugs that most are now shooting in typical AG's likes a much slower twist.
The New production JSAR valve arrived today. Will be installing and testing over the weekend. ;)
Mike
Nice build you have there Ric!
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People will start with short slugs but at some point they will start thinking about longer ones with better BC. Then it comes to things like practical fill pressure, barrel length and how long bullets the magazine will hold. I believe those 225420 bullets are pretty close to what they will end up with assuming magazines will gain some length.
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I asked Jared to make that mould because it should work in the TJ's 14" twist 0.224" barrel.... and the 47 gr. weight (SD = 0.134) means decent velocities should be possible with 3000 psi in a 24-26" barrel.... I achieved 970 fps with the 45 gr. HP at 2800 psi tethered in a 29" with good efficiency (it maxed out at 1010 fps)….
Bob
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I asked Jared to make that mould because it should work in the TJ's 14" twist 0.224" barrel.... and the 47 gr. weight (SD = 0.134) means decent velocities should be possible with 3000 psi in a 24-26" barrel.... I achieved 970 fps with the 45 gr. HP at 2800 psi tethered in a 29" with good efficiency (it maxed out at 1010 fps)….
Bob
24" barrel and 980 fps at slightly under 3000 psi. It's about the longest practical bullet unless we go for .172 caliber.
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Not so sure about that.... TJ's make a couple of faster twist rates in .224 cal.... I have a 9", and I believe they also make a 12".... Of course you need more pressure to take advantage of the longer, heavier bullets.... The exact same gun as above, running unregulated at 3800 psi, gets 960 fps with a 61 gr. bullet (125 FPE) at 1.24 FPE/CI (and maxes out at 1000 fps).... and can always be tethered at that pressure....
Bob
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Not so sure about that.... TJ's make a couple of faster twist rates in .224 cal.... I have a 9", and I believe they also make a 12".... Of course you need more pressure to take advantage of the longer, heavier bullets.... The exact same gun as above, running unregulated at 3800 psi, gets 960 fps with a 61 gr. bullet (125 FPE) at 1.24 FPE/CI (and maxes out at 1000 fps).... and can always be tethered at that pressure....
Bob
By practical I meant something that's useful at sub 3000 psi. Although we have fancy rifles taking 4500 psi fills many are still limited by 3000 psi fill of most factory guns.
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By practical I meant something that's useful at sub 3000 psi. Although we have fancy rifles taking 4500 psi fills many are still limited by 3000 psi fill of most factory guns.
Yes we have....But not factory... It ain't fancy. >:( It is awesome :P
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Ric, I didn't answer your question. the barrel is a Brownells .223 barrel liner that mic's in at .2213. Twist is 1 in 20. I wanted it for shorter bullets. I also have the same barrel in 1-16 for testing as well.
The .250 Raptor barrel is 1-22 twist.
Mike
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By practical I meant something that's useful at sub 3000 psi. Although we have fancy rifles taking 4500 psi fills many are still limited by 3000 psi fill of most factory guns.
Yes we have....But not factory... It ain't fancy. >:( It is awesome :P
It's awesome if you have a compressor. Otherwise you get a 300 bar from diveshop that ends up 270 bar as the bottle cools down. If your gun needs 250 bar fills you won't get many fills from that bottle and you'll be back in the diveshop for another 270 bar fill etc. Not so awesome IMO. That's why I prefer guns that work at 200 bar or less.
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By practical I meant something that's useful at sub 3000 psi. Although we have fancy rifles taking 4500 psi fills many are still limited by 3000 psi fill of most factory guns.
Yes we have....But not factory... It ain't fancy. >:( It is awesome :P
It's awesome if you have a compressor. Otherwise you get a 300 bar from diveshop that ends up 270 bar as the bottle cools down. If your gun needs 250 bar fills you won't get many fills from that bottle and you'll be back in the diveshop for another 270 bar fill etc. Not so awesome IMO. That's why I prefer guns that work at 200 bar or less.
Yeah but when you participate in competitions there is always compressor and you get full bottle when leaving. And I mean full. You should know.
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Hi all!
I have been speculation a bit and I think that the .223 may be the easiest and cheapest option for someone who whant to get into bullet shooting!
So here are a list of advantages!
1. There are plenty of cheap .22lr liners in lenghts up to 28" for some tens$
2. The twist rate is commonly 1-16 which is good for bullets in 30-40gr range.
3. The grove dia is commonly .223 (some are .222) and there are cheap ammo available and some bullets molds exist too and sizing bigger .224 bullets should not be a problem if needed.
(Link 250 bullets for 8$ https://northamericanarms.com/shop/parts/cbb3/ (https://northamericanarms.com/shop/parts/cbb3/))
How about JSB .22 pellets with a head diameter of 5.52mm (.2173") through a .22 LR liner?
https://www.pyramydair.com/blog/2005/12/pellet-head-sizes/ (https://www.pyramydair.com/blog/2005/12/pellet-head-sizes/)
What does a pellet head do?
A diabolo pellet only touches the bore in two spots – at the head and again at the tail. The tail is sized much larger than bore size to seal the compressed air or gas behind the pellet. But, the nose doesn’t seal anything. It acts as a guide for the pellet. It can either ride the bore, which is the top of the rifling lands, or it can ride the grooves, themselves. If a pellet is marked by rifling on the nose when run through the barrel with a rod, it is riding the grooves, which is the most common way.
(https://www.pyramydair.com/blog/images/diabolo-web.jpg)
Lothar Walther lists a land (bore) diameter of .217" along with a .222" groove diameter for their .22 LR barrels which would make the JSB pellet (head diameter .2173"/5.52mm) bore riding for the nose.
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I just noticed Lothar Walther lists the finished .22 LR barrels with a different bore and groove diameter (.217" bore with .222" groove, which is indeed the SAAMI spec)......
https://www.lothar-walther.com/drop-in-gun-barrels/ruger-precision-rimfire-barrels/1433/ruger-precision-rimfire-stainless.22l.r.-mud-1/2-28-unef-2a-l-20.50?c=502 (https://www.lothar-walther.com/drop-in-gun-barrels/ruger-precision-rimfire-barrels/1433/ruger-precision-rimfire-stainless.22l.r.-mud-1/2-28-unef-2a-l-20.50?c=502)
compared to the .22 LR blanks are listed at .216 bore and .221 groove.....
https://www.lothar-walther.com/gun-barrel-blanks/rifle-barrels/rimfire/cylindrical/316/barrel-blank-stainless-twist-16.4.22l.r.-od.91-l-26.18?c=34 (https://www.lothar-walther.com/gun-barrel-blanks/rifle-barrels/rimfire/cylindrical/316/barrel-blank-stainless-twist-16.4.22l.r.-od.91-l-26.18?c=34)
Maybe the blanks are tighter because they are match barrels?
In any event the official SAAMI spec for .22 LR is .217" bore (lands) with .222" groove.
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I think these slugs would be interesting with the 1-16" .223 barrel liner:
https://www.mp-molds.com/product/552-mm-air-rifle-pellet-8-cav-mold/ (https://www.mp-molds.com/product/552-mm-air-rifle-pellet-8-cav-mold/)
(re: I have read this (and the mold sized .03mm larger) have a .223 rear drive band. They were designed by Gregor Kamensek for use in the Huben K1 .22)
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I have this mold in .250 and it is a laser. However, I wonder about the size. 5.52 is .217 in dia. Not .223.
My barrel is dead on .223. GRRRR!
Knife
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I have this mold in .250 and it is a laser. However, I wonder about the size. 5.52 is .217 in dia. Not .223.
My barrel is dead on .223. GRRRR!
Knife
Here is where I got the info on the rear drive band:
https://www.newenglandairgun.com/huben.html (https://www.newenglandairgun.com/huben.html)
.22 @ 35 gr x (10.66) long x .217 (5.52) body .223 (5.67) dia seal.
.22 @ 35 gr x (10.66) long x .218 (5.55) body .223 (5.67) dia seal.
.25 @ 47 gr x (10.86) long x .250 (6.35) body .253 (6.45) dia seal.
Does your MP mold drop the .25 cal version with a .253 rear drive band?
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Gregor use quite hard alloy... on YouTube he has some casting video's. I think he drops some Linotype in . I can't say if those molds are designed based on Gregor's alloy. I have both that Huben mold and .25 mold. Haven't casted that .25 yet and can't remember which diameter that Huben mold drops. I use Pb and 2 % Sn alloy. But there was on MP's web shop sizing die on Huben which is .222,8 and that is based on Gregor's tests on version I Huben .... Those video's are probably also on Gregor's YouTube channel
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Gregor use quite hard alloy... on YouTube he has some casting video's. I think he drops some Linotype in . I can't say if those molds are designed based on Gregor's alloy. I have both that Huben mold and .25 mold. Haven't casted that .25 yet and can't remember which diameter that Huben mold drops. I use Pb and 2 % Sn alloy. But there was on MP's web shop sizing die on Huben which is .222,8 and that is based on Gregor's tests on version I Huben .... Those video's are probably also on Gregor's YouTube channel
At 11:09 in the following video Gregor does mention the rear ring needing more force to push in compared to the front ring---> https://youtu.be/CodtHHnTT9o?t=658
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First time I have seen a mould for CB (conical ball) .22 rimfire ammo....
Does this qualify:
https://noebulletmolds.com/site/shop/224/223-38-rn-cc1/223-38-rn-cc1-3-cavity-hb (https://noebulletmolds.com/site/shop/224/223-38-rn-cc1/223-38-rn-cc1-3-cavity-hb)
(https://noebulletmolds.com/site/wp-content/uploads/2019/11/223-38-RN_PB_CC1_Sketch.jpg)
P.S. This is the heaviest (as cast) bullet I can find so far in .223. Surprisingly it is also .489" in length due to the ogive raidius.
EDIT: Looks very similar to the .22LR reloader bullet (38 grain) Scotchmo mentioned he uses ---> https://www.gatewaytoairguns.org/GTA/index.php?topic=159220.msg155901013#msg155901013 (https://www.gatewaytoairguns.org/GTA/index.php?topic=159220.msg155901013#msg155901013)
http://22lrreloader.com/design-details/ (http://22lrreloader.com/design-details/)
(http://22lrreloader.com/wp-content/uploads/2014/07/22-lr-reloader-bullet-molds.png)
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no the NOE round is not a conical ball round... here in America it is called a CB cap and in the E.U. it used to be called 6mm Flobert after the inventor iirc... it has it's own case shorter than .22 short... If it is a round nose it is called a BB cap...
https://www.google.com/search?q=.22+cb+caps&rlz=1C1GNAM_enUS688US688&source=lnms&tbm=isch&sa=X&ved=2ahUKEwijqeOrqK_qAhWKq54KHXWjD34Q_AUoAnoECBcQBA&biw=1088&bih=474 (https://www.google.com/search?q=.22+cb+caps&rlz=1C1GNAM_enUS688US688&source=lnms&tbm=isch&sa=X&ved=2ahUKEwijqeOrqK_qAhWKq54KHXWjD34Q_AUoAnoECBcQBA&biw=1088&bih=474)
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Also the CB/BB caps were originally meant for smooth bore but work in 1:20-1:24 twist .22 short barrels best...
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For .22lr bullets https://www.krale.shop/en/airgun-pellets-rws-5-7-mm-41-4-grain/ (https://www.krale.shop/en/airgun-pellets-rws-5-7-mm-41-4-grain/) and https://www.opticsplanet.com/lyman-rifle-bullet-mould-22-caliber-225438-2660438.html (https://www.opticsplanet.com/lyman-rifle-bullet-mould-22-caliber-225438-2660438.html)
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For .22lr bullets https://www.krale.shop/en/airgun-pellets-rws-5-7-mm-41-4-grain/ (https://www.krale.shop/en/airgun-pellets-rws-5-7-mm-41-4-grain/) and https://www.opticsplanet.com/lyman-rifle-bullet-mould-22-caliber-225438-2660438.html (https://www.opticsplanet.com/lyman-rifle-bullet-mould-22-caliber-225438-2660438.html)
I have a few thousand of them that I had purchased for the Evanix K550. They do shoot very well. I size them down to .2214” . I do prefer the cast 225-39 sized to the same.
If I could get a used for a good price , Winchester 70-35 I would convert it to .224 cal . The 257 conversion I already have is awesome , can’t believe there aren’t more of these out there converted to smaller calibers. Wait I know what it is .............. the ugliest stock ever made.