QB .224

[Prouzy]

I had been considering this for a while, and after inquiring about some of the technical specs around, specific rsterne and Mountain Air (thanks Bob and Roy) I started. Its a 26in TJ 1:14 twist fitted to QB78 with a custom flow through bolt and air tube from Mountain Air. Roy also did the barrel work, sent directly to him. Im so impressed with Roy's work, everythings fits perfect.  I left the barrel stock, as I thought O would carbon fiber and still might, but seems nice and sturdy in this cal.  Ive not done any modding yet, with the exception of removing piercing pin, felt, and washer. Filled to 1000psi to check for leaks and function, all seems good. Will begin on internals soon.  Ive got the NOE 37gr mold as well as Lee 55gr, though it is not calculated to stabilize the 55gr with that twist.  We shall see.  Sorry for crappy pics, will ne taking more.

[Ribbonstone]

Interested in how that 1:14 twist works out.

Roy does do nice work.

[Prouzy]

Its estimated the 37gr should stabilize fine, but the 55gr not so much. Makes sense, as in a .223 you kinda want to shoot something like that with typically 1:9, 1:8.

He does do nice work, and prices are quite reasonable!

[KnifeMaker]

You can also get ready made bullets at North American Arms. Yep, the same people who make the cool little Pocket Pistols!

They make a Black Powder version of their little gun, and sell .22 short bullets for it. Very similar to what was sold in Europe for years, but now unavailable.  The NAA bullets are very inexpensive.

Enjoy your new toy!

Knife

[imadunatic]

You can also get ready made bullets at North American Arms. Yep, the same people who make the cool little Pocket Pistols!

They make a Black Powder version of their little gun, and sell .22 short bullets for it. Very similar to what was sold in Europe for years, but now unavailable.  The NAA bullets are very inexpensive.

Enjoy your new toy!

Knife

Wow.... very inexpensive is right: https://northamericanarms.com/parts/parts-cb/

[Prouzy]

You can also get ready made bullets at North American Arms. Yep, the same people who make the cool little Pocket Pistols!

They make a Black Powder version of their little gun, and sell .22 short bullets for it. Very similar to what was sold in Europe for years, but now unavailable.  The NAA bullets are very inexpensive.

Enjoy your new toy!

Knife

I had not seen those, very cool! Thanks Knife!

[K.O.]

I cut down some of the Bator   225-55 rf and some of the new  225-55-rf just to get an idea what that would look like and weigh...

pics in post #2  http://www.gatewaytoairguns.org/GTA/index.php?topic=117034.msg1125152#msg1125152

I think on the new 225-55 the mold can handle being milled enough to remove the gas check bringing the weight down to about 48g while reducing overall length by about .09 (then would be about .5" long)... should be about right for the 1:14 twist...

if you can mill the mold enough to take the rear band off then it is down to about 40g and overall length would be down to about .45"... not sure the mold could handle milling that much tho...  you would end up with heeled round with a small .226 rear band on a long .220 nose that should bore ride in the .219 bore/.224 groove barrel...

I am thinking of making some simple jigs to  experiment with cutting them down by hand but have been a bit busy and have not got after it yet...

any ways those are  theories rattling around in my head..

[Prouzy]

Kirby

great info, thanks!  I bought the Lee mostly to practice and try out for giggles, but was thinking about a way I could get it into the mid-40gr-ish without too much effort.  Im also going to need the push through set from NOE as this barrel seems on the small side and Im not confident I want to attempt shooting my sized 37gr through.  You seem to know whats what, can you tell me why there are sizes for nose and body? Im new to casting and thus far only used Lee sizer that has worked well for everything Ive done so far, but the die set and bushings seems like a great option.  Thanks! Chris

[Ribbonstone]

Only recent airgun cast bullet playing I've been doing has been in a different direction.

Rather than rebarreling, been adapting the bullet to the barrel.
(And some thoughts on twist rate/bullet weight along the way.)


One mold...3 bullets:



BULLET "A":

Only .22 mold I still have is a Lyman #225415...a too heavy (55gr) gas check design I had used for reduced loads in faster twists centerfires.  Long bullet, about .594". Really soft allow would run about 55.8grains (including gas check).

Worked great in 1:10 and 1:14 twist centerfires, but even at the super-reduced speeds for those, was still faster than an airgun is likely to go (1800-2100 fps).



BULLET "B":

Some years back, got a 1:16 twist center fire, and found that after I milled the gas check base off thst mold,  the length was .515" / weight aabout46- 47grains,  and it would "kind of" work in a 1:16 twist if I drove it fast enough.

(OK...I really didn't "mill" back then.  HAd use of a large lathe at the time. After removing all the hardware of the mold blocks, chucked into a 4 Jaw cuck, got it running on center and level, and took lathe passes across the mold's base to "lower" it.)


BULLET "C":

Wanting to try cast .22's in an airgun, gave that same shortened bullet "B" a try in my M-10. 

Total failue in accuracy (as expected) but did manage 60 foot pounds.

Best measure of the M-10 had the barrel with a 1:16 twist. Shortend the BULLET, not the mold by borrowing some time on a friend's jewlery lathe and sized by converting a case knurling tool (which expains the cross-hatched markings).

(OK...I should explain that....was a time when .38specail WC loads ruled the centerfire pistol roost. Was a segment of the shooters that believed that knurling/grooving  the case to hold the bullet in place was the way to go over complete case sizing and a  roll or taper crimp...so they actually made 3-roller/adjustable/ squeezers to roll a knurled band in the case....which is what this was converted to work from.)
 

Wich lead to modding bullet "B" into bullet "C".  didn't pay attention to weight, just shortened the bullets, "sized" them, and  shot some samples.

Started to shoot actual groups once it got to .433" length/ 40.3gr.



Not the most scientific way of judging bullet diameter, but I stopped at the diameter than would let me close the bolt with a hard thumb push to the back of the bolt body.  That eneded up being  somthing between .2225" and .223"...so I'll call it .2227".

The "Crosshatching" is tiny, and doesn't seem to matter to rifling engravement.




Will be a good one to test lubes with...hatch markes are lite, don't bother rifling engravement, but likely hold enough lube to make a difference (so far, dry teflon is the only one tried...so far).

[Prouzy]

Very interesting RS! I just sold mu M10, too many projects........such potential from that platform.....

How many grooves in that barrel???

Frankly, I will try anything. And it was mentioned to me, "you build something amd find a bullet to match." Ive not found that that to be completely relevant in airguns.  First off, JSB have consistently shoots better than most, obvious occasions, but likely due to QC, quality in manufacturing, etc.  Some actually build around ammo, eg Crosman, FX. But why wouldnt it be possible to manipulate certain components of a projectile, considering solids/bullets? So I figured I should be able to do something.  Heck, Ive bought .30 pellet shooters with few options in ammo and done ok :-)

[Ribbonstone]

10 grooves for sure...shot one into a tall stack of "wet-lap" (soaked news print), recovered the bullet.
colored the grooves, then counted them.....it's what came with the factory rifle.

If I went larger with the sizing, would have b=to "whack" the bolt closed....if I went smaller, wouldn't get that clean engravement...so I set the sizer (lets just call it a radial compression sizer) to where it is now (hard hand seating/full engravement).


Have an issue with "marital bliss". Wife thinks the young raccoons are "cute", so I kind of ran out of test subjects...at least until they get full sized, battle with the neighbors dogs, raid our trashcans, take up residence under the house A(Raised house), and make themselves the pest they are destined to be.


When that happens (and it will), will get some more "meat" examples.


It's not like the accuracy is really -really poor...think I can improve that with better attention to detail and perhaps a lube on the long bearing area....more that "she who must be obeyed" would be greatly PO'ed (at this time) If I started putting "Rocky's kids" on the grill.

No guilt...no defence...no "nuthin"...am a tried and tre "southerner", raised by a mix of " Alabama Cracker" and "Cumberland gap Hillbillie", and spent almost all of my life with "Cajuns"...'coon and BBQ go together.

[K.O.]

well like I said 'bove, theories..

the nose sizer inserts in theory are to size noses... why?   to bore ride the nose if the round has enough bearing surface to support it, for us using air it cuts down friction...

great in theory to get the nose sized custom to your bore...but... the devil is in the details of implementing it...

http://noebulletmolds.com/smf/index.php?topic=1372.0

http://castboolits.gunloads.com/showthread.php?325303-Anyone-use-NOE-nose-sizer-on-a-powder-coated-NOE-311-247

Bore rider

http://castboolits.gunloads.com/showthread.php?28411-Bore-Rider


I actually have  not cast my own until recently... but grew up knowing folks who did and have sent many cast rounds down range... so listened and watched/helped the casting reloading processes... even got to shoot paper patched 45-70  just like they did in the old days ..  

 I also was a Mold/Core maker on the sand side of an aluminum foundry for a while... so knew to look at melt temp, mold temp and different alloys and their effects...

then it becomes an exercise   in problem solving... and knowing what info to look for...

some are saying not to bother with trying different alloys just stick with 1-2% tin 98% lead...

just maybe an un-choked barrel sending a bore rider(say like the above cut down 40g & 35g) might like a slightly harder alloy..? especially if land engagement was a bit shallow...then it may not be necessary or could help... It will be fun finding out...

http://castboolits.gunloads.com/showthread.php?192192-How-does-alloy-mix-affect-casting-size ...
http://castboolits.gunloads.com/showthread.php?261058-How-Much-do-Alloy-Bullets-Soften-Over-Time ...

in post #35 in below link are some .250/.252 BBT push thru and then  below after sizing to .250 for one of my two .25 Mrods barrel...

need to work on the leade...

the  one with no leade work at 700fps is right at 2 moa... the other Mrod the leade was worse... was 2+ moa at 750 fps... did a little work on that leade... is to about 90% of where it needs to be... but is now at 50 yards  right at 1.75 moa with a flier here and there when they do not chamber right...now that things are warming will get to it... I am pretty sure will get at least to moa once I work out the kinks...

on the right(in the pic) I have the NP XL725 barrel that will be the next experiment... you can see just how close the round is to being just right...  I need get it to drop just a touch larger...

http://www.gatewaytoairguns.org/GTA/index.php?topic=119504.20

so for that barrel I need to run the mold and melt as cool as I can and still get good fill out and no wrinkling... If that does not work then will try an aged antimony alloy... barrel has no choke and is about 1:19 twist so it should be fine with a slightly harder alloy...

In that thread he got them working in his barrel by knurling with a couple files...

in the end only one way to find out...and Keep notes..

[Ribbonstone]

Have an idea of how may sizers I'd really-really need?

The next two statements aren't just me, they are published (and confirmed by trial) by Lyman and other mold makers:

1. The harder the alloy, the larger the cast bullet, and the larger the bullet after sizing (YES...harder allow has a bit of "spring back").

2. The softer the alloy, the smaller the cast, and the more close to sizer diameter it is after sizing.


There are 4 cures for that.

1. Buy pure metals and blend them yourself.
2. Buy pre-made alloy from a known-to-be-good cast bullet company.
3. Buy bullets from a known-to-be-good airgunner bullet maker.
4. "Blend" the alloy at hand.


Now that last one (#4) is a lot of hard work (some of this from big-bore black powder shooting...which has a lot in common with airgunning).

Lets say you have an 80 pound big pile of scrap lead of various hardnesses.

Empty the casting pot (lets pretend it's a 20 pound pot).

1. Fill pot it will scrap alloy.

2. Melt it and cast ingots until the pot is empty.

3. Mark all those ingots with a "1" (roman numerals  are easy to punch into an ingot with a flat screw driver).

4. Do it again with another pot-full of scrap, but punch each ingot with a "II".

5. By the time you've done 4 pot fulls, will have 4 piles of ingots, numbered 1=4.


NOW you have at least 80 pounds of cast lead of the same alloy, same hardness,  from the same mold, and likely pretty much of the same diameter to start...so will likely be the same diameter after sizing

6. fill the now empty pot with 3 ingots for each of the 4 numbered piles (12 pounds).

7. Cast bullets until the pot is about 1/3 full.

8. Toss in 2 ingots from each of the 4 piles (will be near 20 pounds at this point).

9. Keep refilling the pot with 2 ingots from each pile when it gets to 1/3 full.



AND..I disagree about Antimony. It doesn't do "Jack" for hardness....but it does do something for surface tension.  A little Antimony lowers surface tension, and in little-bitty molds, lets the lead fill out the fine edges of the mold.  Tin doesn't so that nearly as well.   Can certainly get by with just leas and tin when casting bigger bore bullets (lets say over7mm), but with the little ones, need that reduced surface tension to get it "mirror image" to the mold.




I already write off the above example bullet/pellet as having too much nose (unsupported weight).  Something "stubbier" would likely shoot better (if I control the alloy and get the sizer right).

But (for me) it's not so much about getting the best of the best...it's more about getting the best of what-I-got.

[Prouzy]

Very interesting.......and bbq coons?  Ill try most anything once!

Ive only cast with pure lead at this point, and have had decent results with what Ive done so far.  This .224 will provide some more play time for sure.  Not sure I will take the path of nose sizing, at least not yet, but looks interesting.  So at least with pure lead, seems they will come out consistently smaller than alloys, if Im reading this right.  I like how the NOE come in multiple sizes, to make it easier in changing for specific needs, including how large the AG bushing options are.

[Ribbonstone]

Still trying.

Not that I had a great big problem with the last effort, but was thinking the evidence pointed to shorter lengths = better accuracy, so I thought I'd try a batch 1/10th inch shorter.


Made a few small batches for testing (small being 25-30 of each) of a lighter weight.  Shorter by 1/10th inch, so lighter (more like 35.3gr.).  These are litely lubed.


Problem may be that now the unsupported length of the pellet (the nose) is longer than the supported region...and that usually results in large groups.



A bit more attention to detail, ruthless rejection rate QC, and ended up with a pretty nice looking cast slugs (although the knurling is a little off-putting).


Ran out of good light for testing today...will give it a try tomorrow (weather willing).

[Prouzy]

I may have missed this, but what are you using to knurl those?

[Ribbonstone]

His tool...started off life as a C-H case cannerlure tool, but it had to be modded a bit.  I'll hunt up a 'net picture.  Think the C-H tool is still made, but +100 new...and you have to mod it to work(it wasn't made for knruming lead bullets, was made for knurling a crimp goove).

They've likely been making this thing for +50 years, and used ones do show up now and again at various sites.

https://www.ch4d.com/products/equipment/bullet-tools/CanToo

Made a tall knurling ring to fit on the shaft of the original... as I didn't want to goove the bullet, but to knurl it (and reduce it's diameter that way).

Corbin makes one that would work... it's not cheap (like $180).

Wouldn't do it....in my case, was working with what I knew was at hand (so "free").  ONc I figure out the length/dimaeter that works best, will go ahead a make a tradtional sizing die and buy a new mold (or beg some big-lathe time to lathe the base down farther on this one).

[Prouzy]

I see.........I may try something before going the Corbin route which Im sure is nice, just not sure how much I would do with it.

In just some basic testing after slugging the barrel, looks like Ive got a really good fit with the NOE 37gr.  Un modified valve for flow and TP, with two shims (arbitrary washers) behind hammerspring, just over 500fps @ 1400psi-ish.  Did not check for accuracy but seems to be in the general vicinity.  Not enough pressure for the 55gr 

[Ribbonstone]

A quick (between really ugly/strong  thunderstorms) .22 M-10  comparsion this afternoon.

Test rifle:




Pellet/slug choices (L-R)
Store bought pellet (JSB 25.4gr.)
Swaged  about-30gr. pellet.
Cast  about 35gr. pellet (harder lead).




Same pellets shot into "wet lap" just to see how they take the rifling.  Evidently, even with soaking wet news pring, the faster/softer pellets actually expanded....but there is still enough "shank" left ot judge that the rifling "took" rather than "stripped".




And one 5-shot try at 25 yards with each.   This rifle really likes the 25.4gr. JSB', which haven't been the most popular choice, but the results are  quite in-line with previous tests.




Can draw yourown limited conclusions/predictions.  Until I test the same 3 pellets at 2 or 3X the range, and for 3-4X the number of shots,  will remain just limited data predictions.


(But as I lay in wait for trash-rading racoons, I'm using the cast bullets.)

[Prouzy]

Those look good.  Do you size then knurl and/or size differently?