GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Ribbonstone on November 05, 2016, 07:49:21 PM
-
Courious about cast-slug shooting in a .22.
Have a .22 PCP that's really not getting too much use. The .25's are getting the high power uses, the .177's (and some 5mm's) getting the low power uses, and this .22 just kind of gets over looked (the "middle child").
Test .22 rifle: BAM 51. NO CHANGES in barrel. Trying to fit the home-cast slugs to the barrel rather than the barrel to the slugs.
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/d3b74a87-ca20-4487-a349-7152a6a43ece.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/d3b74a87-ca20-4487-a349-7152a6a43ece.jpg.html)
Rifle was left off shooting "normal" pellets to about 30 foot pounds with a low presure tune. Don't really want to retune it uless cast slugs seem like a possible option.
being both cheap and cautious, wanted to ry whatever I could rig up at home before commiting myself to slugs.
Only have one .22 centerfire mold and it's been modded to work with a 1:16 twist centerfire at 1100-1500fps. Base pour mold, with the base shortened a little to end up just under 50 grains (and pretty much remove the gas check base). Works fine in a .224" barrel sized to .225" and shot at 1100-1500fps.
With an airgun, it is way-way too fat. Smallest size sizer die II could rig up brought them down to .2224", which still needed a little "urging" with a rawhide mallet to close the bolt.
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/7497bbdb-a85d-4d89-a377-604c15de4db2.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/7497bbdb-a85d-4d89-a377-604c15de4db2.jpg.html)
At least they took the rifling well without making tail-fins on the base, but still too fat and too long for an airgun barrel at 1/2 the speed they get used in reduced centerfire loadings.
LIKELY somthing like ..218/.219" would be tight, but work. Maybe .217"?
A little labor intensive to size them with the junk-yard collection at hand, so only made/tested 20. 10 went into chronograhp readings, 5 for one taget, and the last 5 for "capture" in test media (only 2 really survived in measurable shape).
The one at a steel plate certainly didn't survive:
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/56482a27-0d19-4aad-a33f-d4c77c631165.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/56482a27-0d19-4aad-a33f-d4c77c631165.jpg.html)
It's also too long to stablize at this low speed (less than 1/2 the speed it usually gets shot). That's asking a whole lot of a 1:16 twist barrel. Need somthing both lighter and "blunter" (shorter).
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/6c2c7f91-baa2-483d-b39b-c0ebdc6958af.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/6c2c7f91-baa2-483d-b39b-c0ebdc6958af.jpg.html)
Got a bit lower energy than the 21gr. pellets, but there is a whole lot more bearing area on those bulets...which is friction...which robs power at this setting.
Am going to guess, from years with this rifle, that tuned back up to high pressure and speed, nothing done to the valve, am likely to be able to launch 38-41gr. pellets somewhere between 800 and 860fps. Lets call it 840fps/ 62 foot pounds.
Learned enough to consider retuning this one to a slug-shooter, but have some questions.
1. Who has .217-.219", solid, short, blunt nosed slugs of about 37-41grains?
2. Would a different diameter be better (for an un-modded barrel)?
-
NOE bullets has a mold in group buy stages . http://noebulletmolds.com/smf/index.php?topic=1172.0 (http://noebulletmolds.com/smf/index.php?topic=1172.0)
-
First there is the new BBT 30g coming soon in both .217 nose/.219 base band and nose and then the same design in .220 nose/.222 base band...
http://noebulletmolds.com/smf/index.php/topic,1322.0.html (http://noebulletmolds.com/smf/index.php/topic,1322.0.html)
Now (THANK YOU Al) there is the N.O.E. sizing system in air rifle sizes that uses these to size the round to what your barrel prefers
http://noebulletmolds.com/NV/index.php?cPath=104&osCsid=2aodkdjuaq6tfg6lmeec8nii67 (http://noebulletmolds.com/NV/index.php?cPath=104&osCsid=2aodkdjuaq6tfg6lmeec8nii67)
http://noebulletmolds.com/NV/index.php?cPath=104_411&osCsid=2aodkdjuaq6tfg6lmeec8nii67 (http://noebulletmolds.com/NV/index.php?cPath=104_411&osCsid=2aodkdjuaq6tfg6lmeec8nii67)
Then there is the NOE 37g
http://noebulletmolds.com/NV/product_info.php?cPath=24_117&products_id=413&osCsid=2aodkdjuaq6tfg6lmeec8nii67 (http://noebulletmolds.com/NV/product_info.php?cPath=24_117&products_id=413&osCsid=2aodkdjuaq6tfg6lmeec8nii67)
and then there is the cheaper about 28$ with handles Lee Bator if you can find a used one and the new 225-55-rf which can be decked (I plan on decking two of those and one Bator... cut a few down just to get an idea of the weight and how they look...
-
I'm not sure if Nick does them anymore but I bought 100 of his 22.5gr .217 swaged slugs to try in my Mrod but my bore was way too big in that gun. However having a Mutant I think I'm going to test them and see how accuracy is with them
-
also there are the PDG Heavies at about .27g the spitzer is called the Destroyer I think..
Yep Destroyer ...
http://www.gatewaytoairguns.org/GTA/index.php?topic=87133.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=87133.0)
* will edit my above pic to show weight...also the ones at right(smallest/lightest) can not be made by milling the mold... you would have to carve them from the larger rounds...
-
Those BBTs look promising. I'd love to try some of them in my AT-44 to see what it could do with them. The best part(for me) is they'll fit a Hatsan magazine. I bet I could hit 60fpe with them, since I can do just over 55fpe with the JSB 25.39s. When are the BBTs supposed to be available?
-
Not going to give up quite yet. Pretty sure I have a start on a .218" sizing die, but want to make a nose-fitting punch to push them though base first.
-
Start off by saying how nice it was to get the old warrior out for a little trigger time. Havne't had this BAM 51 out in quite some time (but it held it's air while it waited).
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/2f84a023-4cd2-47bb-a2a7-6e64f873c0bf.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/2f84a023-4cd2-47bb-a2a7-6e64f873c0bf.jpg.html)
Cast bullets at least with what I have on hand, got worse.
Started life as a Lyman #225415 casting about 55gr. bullets (depending on the alloy...softer = heavier). Wouldn't shoot in an old (1930's-1940's) K-hornet's 1:16 twist.
So I lathed off almost all of the ga check base and use it as a plain base .22 bullet in that centerfire (as well as others). So long as it was loaded to go as fast as 1100 and no faster than 1500spf, it shot well.
So I tried that bullet in an airgun, with a smaller sized bore (requiring more sizing down). While th twist rate was the same 1:16, the airgun could only manage about 1/2 the speed.
For sizing, figured a way (by way of an old Lyman 310 tong-tool and using some dies in ways they were not intnded to be uses, figured out a way to evenly size down the cast byllets to .218"
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/c26380fc-1b1c-4944-bf0b-aadbb1dc5cde.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/c26380fc-1b1c-4944-bf0b-aadbb1dc5cde.jpg.html)
BUT, as they got skinnier, they got a little longer too, adn the bearing area (B.Ar. on the picture) got longer too. Not a while lot longer in length as most of the transition from fat to skinny was taken up by the lube gooves.
Did find that sizing the bullets to .217-218" (and if I had to pick, would pick something about mid-point betwen the two) made it possible to chamber the pellets by hand (although, often a smack with the heeel of my hand).
Well...accuracy went to *(&^. velocity increased, but the slugs key-holed.
(http://i157.photobucket.com/albums/t50/ribbonstone/BAM51/067d265c-0c75-47b4-b388-d58717458d07.jpg) (http://s157.photobucket.com/user/ribbonstone/media/BAM51/067d265c-0c75-47b4-b388-d58717458d07.jpg.html)
Think they are just too long to stablize at low speeds from a 1:16 barrel. It's not so much the weight as it is the OAL of the bullet. A nice blunt round nosed 50gr. slug would end up shorter, and likely end up shooting much better.
With what I have on hand, it "ain't gonna happen". Trying some pre-made, shorter, blunter ,217 and .218" slugs is a definated possibility.
But for now, will just keep on using JSB 15.9gr.
-
Haha... Your last post nailed the first thing that came to mind when I saw the pic of the bullets: "He should try some round-nose, just like the old indoor subsonic .22 rounds!"
Those are little, little bullets (somewhere around 40gr, I think...), and the ones I had left the barrel of an old .22lr target rifle at less than 900. They were stupid-accurate. It's been so many years I can't remember anything else.
Have something for you to try. PM on the way.
-
Has anyone tried the BBT gullets from a .22 airforce gun?