GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: luge007 on June 04, 2020, 08:19:52 PM
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This message was originally intended for 'Dyotat100' (the recognized guru of AirForce stuff) but his PM box is perpetually full, so I will submit this to the forum.
Hi,
I realize this barrel idea has been done before, but I'd like to get your advice on selecting a twist rate for a.224 barrel blank to machine for my Airforce Escape.
I was considering Green Mountain's 1:14 twist, BX22mag barrel blank for .224dia. 55gr.-ish slugs from a Lee Bator mold 225-55(that may be hollow pointed and end up lighter) that has a round nose and considerable bearing surface, and a Lyman mold 2660415 gas check, that drops I think 53grains that has more of a tangent ogive with a tiny flat point. The question is, will the 1:14 stabilize these projectiles and potentially provide good accuracy at the 850-1200fps I intend to drive them? I'm also not opposed to milling off the mold to remove the rebated GC portion of the projectile if it is going to degrade accuracy (though I suspect it may improve accuracy at sub-sonic velocities).
GM also has 1:6, 1:7, 1:8, 1:9, 1:12 twist rates in centerfire .224, but from what I have been reading, slower air projectiles like the slower twist rates. I have read reports of a .22 short barrel with a 1:20 twist rate to be extremely accurate with custom sized slugs, but another source leads me to believe a 1:10 is a good place to start for the above mentioned projectiles.
Thank You in advance for your help,
Matt
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I'd personally go with anything between 10-14 twist (can go into my calc and under ammodb sheet put in your bullet data and it recommends a twist rate range for that bullet on the reticle page.)
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Thanks for the response. It's looking like I may end up making several barrels and seeing which one performs best. I was HOPING to avoid wasting money on barrels that will not work well. Perhaps my velocity goals were not realistic with a stock AF platform and such a heavy projectile, no idea but I'll give this post some time and see what turns up.
Cheers,
Matt
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Remember, even though the twist rates you list are for .244 projectiles, you are not shooting at centerfire velocities. You have to look at subsonic .22 velocities.
It all comes down to rpm. I have found that the 1-2- works best for my length of slugs. The slug you are listing is longer, so a slightly faster twist would work. Which would put it into the 1 in 16 to one in 14 range.
Weight has Nothing To Do with it. Hp it and it still will want the near same twist. it is length. Not weight that dictates twist at a given velocity.
Knife
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I built a .224 using a TJ's 1:14 twist. It shoots the Lee 224-55 bullet extremely well
https://www.midwayusa.com/product/1016832078 (https://www.midwayusa.com/product/1016832078)
My mold drops them around 56grains
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Very interesting that NOE offers .224 in some very heavy weights (up to 100 grains):
https://noebulletmolds.com/site/product-category/224 (https://noebulletmolds.com/site/product-category/224)
However, I would not expect 900 FPS from the very heavy ones, but maybe a lower velocity could be interesting --> https://www.gatewaytoairguns.org/GTA/index.php?topic=174190.msg155965518#msg155965518 (https://www.gatewaytoairguns.org/GTA/index.php?topic=174190.msg155965518#msg155965518)
P.S. Here is the Kolbe twist for the 100 grain ---> http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.224&length=1.0&nose=.389&meplat=.128&base_diameter=.224&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.224&length=1.0&nose=.389&meplat=.128&base_diameter=.224&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=) (Starts off a 1 in 7.25" at 500 FPS and progresses to 1in 7.6" at 1000 FPS)
SIDE NOTE: 1 in 7" twist will also work with Bob Sterne's proposed G7 drag profile 75 grain .224--> http://noebulletmolds.com/smf/index.php?topic=1128.0 (http://noebulletmolds.com/smf/index.php?topic=1128.0)
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Duplicate Post.
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Thank You all, so far I am learning a lot and beginning to get a grasp on this (I think).
'Knife' - Thanks for your input as always, I guess the 'weight' issue I was thinking about had to do with length from something I read a long time ago. For a given bullet of 'conventional construction', a lighter bullet will need less of a twist rate, and a heavier bullet a tighter twist rate. All of which directly relates to the 'length' of the projectile, everything else being equal. (see, you can teach an old dog a new trick but I am slow):)
'Sbak'- What sort of velocities were you getting with that 1:14 twist firing those 55 grain Lee bullets? Was it an AF platform? If so, (or not) what modifications were done?
'UnderPressure'- Interesting input on the NEO projectile and twist rate, I was hoping to utilize the 50-55 grain molds I already have in my .224 project since I have pretty much gotten out of firing powder burners, hoping to re-purpose existing molds. At some point I am hoping to MAKE custom molds, start to finish (the right way, utilizing my mill and or lathe) but a lot more learning needs to be done of the process.
Looking forward to more info coming in, despite this topic having more or less been gone over before.
M
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I know that the 47 gr. Arsenal works in a 14" twist TJ's barrel, but I have not tried anything heavier.... I also have a 9" twist TJ's but no accuracy testing yet.... I have bullets as heavy as 61 gr. to try in that, I can shoot those at 960 fps....
Bob
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Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
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Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
Nice...two things I would consider, bush the valve stem bore to 2.5~ mm, run a 2.5mm valve stem. That will help significantly with a bullet shooters, from there you just need to find the right valve spring and hammer spring preload to help 'tame' the closure of the valve to around 97% of peak...and of course a peek poppet. Nice build btw.
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Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
Nice...two things I would consider, bush the valve stem bore to 2.5~ mm, run a 2.5mm valve stem. That will help significantly with a bullet shooters, from there you just need to find the right valve spring and hammer spring preload to help 'tame' the closure of the valve to around 97% of peak...and of course a peek poppet. Nice build btw.
Appreciate it, i should have added, 24in barrel, peek poppet, flat wire spring ssg, and i did experiment with valve springs. My experience has only been with "QB" stiffness springs and less, but the valve spring has zero effect on shot curve. YMMV
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Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
Nice...two things I would consider, bush the valve stem bore to 2.5~ mm, run a 2.5mm valve stem. That will help significantly with a bullet shooters, from there you just need to find the right valve spring and hammer spring preload to help 'tame' the closure of the valve to around 97% of peak...and of course a peek poppet. Nice build btw.
Appreciate it, i should have added, 24in barrel, peek poppet, flat wire spring ssg, and i did experiment with valve springs. My experience has only been with "QB" stiffness springs and less, but the valve spring has zero effect on shot curve. YMMV
You certain you're tuned a little below peak and not over-driving the valve? Other than that, you seem pretty well off. Curious what hammer weight you're running? (sorry for minor threadjack, its semi on topic with discussion of another .224 ;) )
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Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
Impressive!
Do you have a build thread on this?
P.S. How easy is it to load the .580" length LEE 225-55 into the Sentry?
(https://www.castbulletassoc.org/forum/content/uploads/ebd001a9-374a-4cad-8246-26460b0e13cc/73baf7b1-2e61-4a75-9679-a704015da134_lee-mold--lh-225-55--56-gr-sketch.jpg?width=690&upscale=false” alt=)
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I had a TJ 1:14 .224 made for a QB78. While I was waiting for that and the NOE 39gr mold, I bought the Lee 55gr to practice. I sized them down to .220 and tested them for speed in a AF with 24in .22 barrel, over 950fps. That is an unmodified AF "Escape" set up in .25 with the barrel switched out, so you will have no problem getting velocities in that platform. I think we have all had good luck with NOE 225 39 FN in TJ 1:14. I had not seen that the 55gr (Ive never tried, my little QB cant push them) shoots. Thats pretty cool, great pill in that caliber.
I too was looking into GM barrels for AF but the smith I was discussing with wouldnt do the work on the RX blanks to get from 1.20"OD down to the breech dia for the AF. But those BX should make it a little easier. I must say though, Ive had 7 barrels from TJs on various platforms in .224, .257, .300, .308, and .457 and none of them have disappointed.
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The Lee barely fits in the breach, I have to load them in at an angle. Off the top of my head I think my hammer weight was around 50gr. I do know I was a little low in the dwell department and driving the hammer pretty hard to shoot the Lee's. I tried all the modern .225 molds available from NOE, arsenal, and Lee. They all shot great, the Lee is just a little to heavy for my guns hammer energy. The NOE 39gr Lyman copy is a good little round and easy to get up to speed. I took some long range Aberts (tassle eared) tree squirrels way up in the ponderosa's last winter with them. I think they are slightly overspun as you will get occasional fliers at longer ranges, but hole in hole at 75yrds and under.
No, I didn't do a build thread. I would suggest you read up on Bob's .224/.172 build it was the one that inspired mine.
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HAve mentioned this before.....I'd not be too hung up on barrel diameter for a rebarrel. Way easier to make new bushings than to lathe the barrel full length thinner.
Are limits...but the AF frame is pretty darn large on the inside.
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HAve mentioned this before.....I'd not be too hung up on barrel diameter for a rebarrel. Way easier to make new bushings than to lathe the barrel full length thinner.
Are limits...but the AF frame is pretty darn large on the inside.
Its sure been done, but that little breech end may be intimidating for some I guess.
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Remember, even though the twist rates you list are for .244 projectiles, you are not shooting at centerfire velocities. You have to look at subsonic .22 velocities.
It all comes down to rpm. I have found that the 1-20 works best for my length of slugs. The slug you are listing is longer, so a slightly faster twist would work. Which would put it into the 1 in 16 to one in 14 range.
Weight has Nothing To Do with it. Hp it and it still will want the near same twist. it is length. Not weight that dictates twist at a given velocity.
Knife
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Under Pressure, where did you come up with the 'print' for the Lee projectile? It does not look like the Lee "Bator" projectiles dropped by my mold (though mine is about 20 yr old). My Lee mold drops what can be described as cylindrical projectiles with a 'dome' nose and a few lube grooves. I'll post pics if I get a chance.
My guess is the longer bearing surface may require a faster twist rate than my RCBS projectile? Stability comes from the twist rate, or the gyroscopic stability from the RPM which is driven by the FPS as projectile leaves the barrel at, correct? So the "length" of a projectile and velocity determine the twist rate required BUT is the "length" what touches the barrel or the TOTAL length of the projectile?
Almost coming into focus here........
M
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Rather than all the pie in the sky guess work, why not treat the requirements the same as a sub sonic .22 projectile. It has a "very" long track record the world over.
Standard twist for the subsonic is normally 1 in 16 twist. I tried the 1-16 and the twist rate for the .22 short. Oddly enough, the slower twist rate was more accurate.
You will notice soon that the only AG company that has really paid attention to slug use in their guns is FX. The twist rate in the New Superior line is slow as well. Looking forward to the new specs in the forthcoming Superior bbl's. I know what they are, but no doubt get blasted here as many would simply dis. it.
For your purposes, I would go with TJ's. They are very accurate!
Knife/Mike
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Mixing firearms and airarms can often get us in trouble (pressure/obturation is part of it), do think that 1:20 would be enough twist for a .22 AIRGUN slug of somthing like 22-27grains. at 800-900fps.
Considering the .22short started off as a black powder round,and 1:20-1:22" was most often used for that sub-sonic bullet....why would airguns be drastically different?
(Lets avoid CB caps....short or long...they have other problems besides twist.)
If you want to be modern,then there are sub-sonic (30gr).22 shorts and sub-sonic (or even "reduced noise") .22LR's that pretty well dupicate the BP speeds (820-900fps)...which is NOT far from hot PCP speeds (reachable with common PCP's)....and pretty close to observed BP speeds of the orginals.
Stability does not always equate to accuracy....nice round holes (not ovaled or key holed) is a good indication of stability...but they still may not group worth a hoot.
Using the same twisted-comparsion of fire vs airarms,where some .22LR pistols made back in the day with a 1:10 twist....they let that go pretty quickly as too much of a good thing.
Personally....I'd listen to KnifeMaker.
All I wanted to do was turn ONE rifle into a slug shooter and didn't want to rebarrel it. Trial and error got me there,but was casting slugs in a shortened mold and figuring out my own sizging system.....if I didn't have all that happy-whappy-stuff on hand,would have been hosed.
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True you could compare .22LR sub-sonic to our airgun world, however I'll likely (but not a definitely) be shooting 55 grain lead bullets, where as .22 subs are generally 40gr and under, with the exception of the Aguilla SSS round. From what I understand the longer 55 grain bullets should require a faster twist rate than a shorter 40 grain? If I hit the lottery I'd be happy to try every twist rate from 1:10 through 1:20, however at $50- $200 per blank, that is highly unlikely. I was hoping with the specific projectile in question with the guesstimated velocity, an actual calculation for an appropriate twist rate would come forth. Appears there is more 'Voodoo' to this barrel topic than meets the eye.
Knife, I hear you loud and clear, and value your input especially the PM's you sent (thank you), but are you shooting 55 grain, long projectiles in that 1:20? I thought you said you 'decked' your mold and are shooting lighter, shorter bullets. Wouldn't the longer bullets need a faster twist rate? Can you PM me with the new FX slug twist rate, and does FX specify a projectile weight range for their barrels? (I promise not to blast you) ;)
M
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Under Pressure, where did you come up with the 'print' for the Lee projectile? It does not look like the Lee "Bator" projectiles dropped by my mold (though mine is about 20 yr old). My Lee mold drops what can be described as cylindrical projectiles with a 'dome' nose and a few lube grooves. I'll post pics if I get a chance.
I found it while searching images for Lee Bator.
It does indeed look like it comes from this mold:
https://www.midsouthshooterssupply.com/item/0000690459/point225-diameter-6-cavity-mold-c225-55-rf (https://www.midsouthshooterssupply.com/item/0000690459/point225-diameter-6-cavity-mold-c225-55-rf)
(https://www.midsouthshooterssupply.com/images/product_images/006-90459/006-90459.jpg)
Maybe they changed the design of the Lee Bator sometime in the past 20 years?
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You will notice soon that the only AG company that has really paid attention to slug use in their guns is FX. The twist rate in the New Superior line is slow as well. Looking forward to the new specs in the forthcoming Superior bbl's. I know what they are, but no doubt get blasted here as many would simply dis. it.
Hard Air Magazine is reporting their will be two different families of Superior liners:
https://hardairmagazine.com/news/fx-superior-stx-liners-the-latest-introduction-from-fx-airguns/ (https://hardairmagazine.com/news/fx-superior-stx-liners-the-latest-introduction-from-fx-airguns/)
There are two families of barrel liners being released for most calibers; a standard Superior STX Liner and a Superior STX Heavy Liner.
FX Superior STX Barrel Liners
These standard barrel liners have been created to shoot standard weight pellet and Hybrid Slugs. FX tells us that indoor 100 Yard controlled testing has confirmed that the new Superior STX Barrel Liner shoot standard FX pellets even better than the previous STX Pellet Liner!
Keeping in mind the amount of championship wins the STX Pellet liner has, that is a strong statement! The standard Superior STX Liner also maximizes the accuracy of the ground-breaking FX Hybrid Slug.
FX Superior STX Heavy Liners
These new barrel liners will be replacing the STX Slug A liners in the coming months. Heavy denotes that this liner has a different twist rate better suited for heavier pellets and heavier slugs (as opposed to lighter weight Hybrid Slugs).
P.S. The regular superior liner could have a relatively slow twist and yet stabilize many of the commonly available slugs.
Even the 27.5 grain .217 Neilsen Doesn't need that much twist according to Kolbe:
http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.3295&nose=.120&meplat=.150&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.3295&nose=.120&meplat=.150&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=)
(http://www.geoffrey-kolbe.com/images/923675.png)
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I did some more digging on the twist rate for the FX .22 Superior slug liner but couldn't find it.
FWIW Here is a older list from April 2019:
https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/ (https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/)
(https://www.trenieroutdoors.com/wp-content/uploads/FX-Airguns-Twist-Rate-Liners.jpg)
So if the Superior slug liner for .22 ends up 1 in 23" twist could it be the Superior heavy slug liner for .22 is 1 in 19"?
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You will notice soon that the only AG company that has really paid attention to slug use in their guns is FX. The twist rate in the New Superior line is slow as well. Knife/Mike
This here. I bought that new superior barrel near launch. I dont have an FX but I figured I could put it in one of mine.
Then I discovered it wasnt really for slugs thats what the forthcoming heavy superior barrel is for.
Id be interested to see what they do. But I doubt it makes much sense to put this 600mm Superior in my talondor. Im slowly making my way to the .257 on my Airforce
If I recall right for my .25 600mm superior its 1-23.575 But Ive been reading too many twist rates now to keep track
And thats likely too slow for say 50 grain projectile. Because of the length
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True you could compare .22LR sub-sonic to our airgun world, however I'll likely (but not a definitely) be shooting 55 grain lead bullets, where as .22 subs are generally 40gr and under, with the exception of the Aguilla SSS round. From what I understand the longer 55 grain bullets should require a faster twist rate than a shorter 40 grain? If I hit the lottery I'd be happy to try every twist rate from 1:10 through 1:20, however at $50- $200 per blank, that is highly unlikely. I was hoping with the specific projectile in question with the guesstimated velocity, an actual calculation for an appropriate twist rate would come forth. Appears there is more 'Voodoo' to this barrel topic than meets the eye.
Knife, I hear you loud and clear, and value your input especially the PM's you sent (thank you), but are you shooting 55 grain, long projectiles in that 1:20? I thought you said you 'decked' your mold and are shooting lighter, shorter bullets. Wouldn't the longer bullets need a faster twist rate? Can you PM me with the new FX slug twist rate, and does FX specify a projectile weight range for their barrels? (I promise not to blast you) ;)
M
No, my heaviest in .25 is 51 gr's. My .223 is one in 20 and the bbl that JSAR sent me in .25 is 1 in 22. Shoots very well! I only know the twist in the .25 superior, and waiting for info on the up coming heavy and .22 bbl's. ;)
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True you could compare .22LR sub-sonic to our airgun world, however I'll likely (but not a definitely) be shooting 55 grain lead bullets, where as .22 subs are generally 40gr and under, with the exception of the Aguilla SSS round. From what I understand the longer 55 grain bullets should require a faster twist rate than a shorter 40 grain? If I hit the lottery I'd be happy to try every twist rate from 1:10 through 1:20, however at $50- $200 per blank, that is highly unlikely. I was hoping with the specific projectile in question with the guesstimated velocity, an actual calculation for an appropriate twist rate would come forth. Appears there is more 'Voodoo' to this barrel topic than meets the eye.
Knife, I hear you loud and clear, and value your input especially the PM's you sent (thank you), but are you shooting 55 grain, long projectiles in that 1:20? I thought you said you 'decked' your mold and are shooting lighter, shorter bullets. Wouldn't the longer bullets need a faster twist rate? Can you PM me with the new FX slug twist rate, and does FX specify a projectile weight range for their barrels? (I promise not to blast you) ;)
M
So far, the .25 superior is 1 in 24. Waiting to see where the .25 heavy and .22 bbl's. will fit in.
Mike
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So the .25 Superior 1 in 24 must be a pellet barrel?....
Bob
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So the .25 Superior 1 in 24 must be a pellet barrel?....
Bob
Pellet and hybrid slug (so slug too)......but they claim the standard Superior STX liner shoots pellets better than the previous STX pellet liner which is interesting because the twist is 3" faster.
https://hardairmagazine.com/news/fx-superior-stx-liners-the-latest-introduction-from-fx-airguns/
There are two families of barrel liners being released for most calibers; a standard Superior STX Liner and a Superior STX Heavy Liner.
FX Superior STX Barrel Liners
These standard barrel liners have been created to shoot standard weight pellet and Hybrid Slugs. FX tells us that indoor 100 Yard controlled testing has confirmed that the new Superior STX Barrel Liner shoot standard FX pellets even better than the previous STX Pellet Liner!
Keeping in mind the amount of championship wins the STX Pellet liner has, that is a strong statement! The standard Superior STX Liner also maximizes the accuracy of the ground-breaking FX Hybrid Slug.
FX Superior STX Heavy Liners
These new barrel liners will be replacing the STX Slug A liners in the coming months. Heavy denotes that this liner has a different twist rate better suited for heavier pellets and heavier slugs (as opposed to lighter weight Hybrid Slugs).
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I did some more digging on the twist rate for the FX .22 Superior slug liner but couldn't find it.
FWIW Here is a older list from April 2019:
https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/ (https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/)
(https://www.trenieroutdoors.com/wp-content/uploads/FX-Airguns-Twist-Rate-Liners.jpg)
So if the Superior slug liner for .22 ends up 1 in 23" twist could it be the Superior heavy slug liner for .22 is 1 in 19"?
Here is the Kolbe twist for the FX .22 hybrid slug (using my estimate for nose length and meplat):
http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=)
So my mistake twist should be faster than 1 in 23" for the standard superior liner in .22.
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I did some more digging on the twist rate for the FX .22 Superior slug liner but couldn't find it.
FWIW Here is a older list from April 2019:
https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/ (https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/)
(https://www.trenieroutdoors.com/wp-content/uploads/FX-Airguns-Twist-Rate-Liners.jpg)
So if the Superior slug liner for .22 ends up 1 in 23" twist could it be the Superior heavy slug liner for .22 is 1 in 19"?
Here is the Kolbe twist for the FX .22 hybrid slug (using my estimate for nose length and meplat):
http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=)
So my mistake twist should be faster than 1 in 23" for the standard superior liner in .22.
Someone should tell Ernest that. He posted a video shooting them at 1157 / 25y and surmised they would do well at longer range at that velocity ;D
I don't know what to make of that Kolbe graph. My Taipan can shoot them accurately at 100 meters at 990fps with both 600mm pellet (1:19) and slug (1:16) liners. I tested them with both liners from 1195 down, until they grouped well at 1030fps (even tighter at 990). Had identical results with both liners.
I'd say they're ok at that range, but they drift too much with crosswind for me to shoot with them further out.
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I did some more digging on the twist rate for the FX .22 Superior slug liner but couldn't find it.
FWIW Here is a older list from April 2019:
https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/ (https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/)
(https://www.trenieroutdoors.com/wp-content/uploads/FX-Airguns-Twist-Rate-Liners.jpg)
So if the Superior slug liner for .22 ends up 1 in 23" twist could it be the Superior heavy slug liner for .22 is 1 in 19"?
Here is the Kolbe twist for the FX .22 hybrid slug (using my estimate for nose length and meplat):
http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=)
So my mistake twist should be faster than 1 in 23" for the standard superior liner in .22.
Someone should tell Ernest that. He posted a video shooting them at 1157 / 25y and surmised they would do well at longer range at that velocity ;D
I don't know what to make of that Kolbe graph. My Taipan can shoot them accurately at 100 meters at 990fps with both 600mm pellet (1:19) and slug (1:16) liners. I tested them with both liners from 1195 down, until they grouped well at 1030fps (even tighter at 990). Had identical results with both liners.
I'd say they're ok at that range, but they drift too much with crosswind for me to shoot with them further out.
Is the Standard Superior STX liner in .22 1 in 23"?
P.S. According to the Kolbe graph (using my estimate for meplat size and nose length) the FX hybrid .22 slug needs 1 in 21.5" for 900 FPS and 1 in 19.5" for 1150 FPS.
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I did some more digging on the twist rate for the FX .22 Superior slug liner but couldn't find it.
FWIW Here is a older list from April 2019:
https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/ (https://www.trenieroutdoors.com/fx-airguns-twist-rate-data/)
So if the Superior slug liner for .22 ends up 1 in 23" twist could it be the Superior heavy slug liner for .22 is 1 in 19"?
Here is the Kolbe twist for the FX .22 hybrid slug (using my estimate for nose length and meplat):
http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= (http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.322&nose=.160&meplat=.135&base_diameter=.217&angle=&boat_tail=&b_twist=&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=)
So my mistake twist should be faster than 1 in 23" for the standard superior liner in .22.
Someone should tell Ernest that. He posted a video shooting them at 1157 / 25y and surmised they would do well at longer range at that velocity ;D
I don't know what to make of that Kolbe graph. My Taipan can shoot them accurately at 100 meters at 990fps with both 600mm pellet (1:19) and slug (1:16) liners. I tested them with both liners from 1195 down, until they grouped well at 1030fps (even tighter at 990). Had identical results with both liners.
I'd say they're ok at that range, but they drift too much with crosswind for me to shoot with them further out.
Is the Standard Superior STX liner in .22 1 in 23"?
P.S. According to the Kolbe graph (using my estimate for meplat size and nose length) the FX hybrid .22 slug needs 1 in 21.5" for 900 FPS and 1 in 19.5" for 1150 FPS.
I have no clue .. none of my sources seem to know either (FX is being fairly hush-hush about them, they might still be figuring that out).
The Hybrid 22 cal ammo has been (very) accurate at 900 (780-940fps FWIW) using several other rifles that I tested them with. Those bbls were primarily choked LW and CZ with 1:16, 1:17.5. They seem to be preferred with all of my rifles over the 20.2 & 24.8gr NSAs, but no where near as good as those 25gr H&N Slug HPs.
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Guys are getting the heavy superior barrel
They are listed in Krale shop
17.5 for heavy superior in .25 if post I read guy knew what he was doing. He did have photos
Fx impact owners Facebook group
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Guys are getting the heavy superior barrel
They are listed in Krale shop
17.5 for heavy superior in .25 if post I read guy knew what he was doing. He did have photos
Fx impact owners Facebook group
So twist is increasing.
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Sbak
I would be greatly interested in your Sentry build, especially the Flat Wire SSG etc,
photo or two would be a great help, I am leaning very hard in the same direction,
only in the 172/224 cal in the Sentry, as I have several bbl's (RF/CF) that I could use.
I am interested in HEAVY weight pellets and Lite weight slugs, I believe that the Sentry 705 models can work very well,
as they are very well built in the plenum tube and valve areas, and with the 8lb hammer spring that can be changed out
to a Flat wire Hammer spring with more options etc.
I am planning on running a lite weight hammer, to get away from the 746 gr OEM hammer weight etc.
I am waiting on Knives reply to my PM, before I take the next step............... ::)
Thanks,
Don
Ive never worked with the air force rifles, but from what ive seen they should be plenty capable of maxing out the .224 platform. I used a prototype xisico senty, cause im cheap. Although, i really enjoyed this gun i would not suggest it for a high energy build. It is limited in hammer energy by design. I have it maxed out in hammer weight and travel and it is still pretty hard to cock.
I was able to get a little over 900 fps maxed out @ 3000 psi with the 56 gr lee. .22 porting minus .10 probe (.203 equivalent). From 3000 psi to 2500 gave a tune of 850-870-850 for i think 6 shots on 240cc of air. It has since been detuned for 20 shots @ 65FPE with the NOE WFN
The .224 is a very underappreciated caliber, mine shoots pretty much everything fantastically
Appreciate it, i should have added, 24in barrel, peek poppet, flat wire spring ssg, and i did experiment with valve springs. My experience has only been with "QB" stiffness springs and less, but the valve spring has zero effect on shot curve. YMMV
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Guys are getting the heavy superior barrel
They are listed in Krale shop
17.5 for heavy superior in .25 if post I read guy knew what he was doing. He did have photos
Fx impact owners Facebook group
Any mention of .177 superior liners (both standard and heavy)?
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So, here is a pic of the actual slugs that came out of my Lee "Bator" mold. These were setup to be propelled by powder, so disregard the gas checks on these, the air powered ones will not have checks. As you can see they are very cylindrical and have a rounded nose, very dissimilar to the diagram and pic previously posted. I can attempt to take accurate measurements and post them if that is helpful for further advise, but they are .545" long. They have a huge meplat for their diameter, so I am considering modifying the mold to hollow point them. The HP process will make them lighter for easier 'propelling', and hopefully dump all their energy on impact. Could also use them non-hp for penetration.
I am leaning towards a 1:12 twist for these projectiles.
Thanks for all the input so far, keep it coming,
M
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Sorry I have no answers Guy's. I'm still trying to get the twist rate for the "Heavy" .22 liner.
Guess I will have to Waite until it gets here and check it myself LOL!!!
I will post the twist rate as soon as I can measure it. ;)
Mike/Knife