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I have an old Ishapore 2A1, that I want to experiment with. I want to get some 'super-heavy' cast boolits, 300 AAC Blackout 245 grainers, and see what kind of accuracy I can squeeze out of her, I am looking for a relatively low speed, hopefully subsonic.
I cant really find any data about using 300 Blackout bullets in 308 Winchester cases.
I have some BlueDot, IMR4227, IMR4064, IMR4831, RL-15, N-140, FFg Pyrodex, IMR3031, and IMR 4198 to play with... thoughts?
My first thought was "will it stabilize?" The 7.62 NATO was originally specced with 1:12" twist, but I don't remember offhand what twist was supposed to be in the 2A1.
Lee's 2nd ed has a little bit of data for 225 grain lead, but no heavier, also all of the powders they use are slower burning and with higher velocities than you want to try.
Good luck,
Robert
I think your going to have some stability problems over 200 grains for sure.
You need a 1-10 twist. Pat
Here's a link regarding the twist rate:
http://castboolits.gunloads.com/show...n-Ishapore-308
I have a close to mint 2A1 in the vault that I shoot with M80 ball from time to time with about 3 MOA accuracy. Believe it or not, I've sometimes shot MOA groups (10 shots @ 100 yards) with M852 Match ammo with it.
Of course that doesn't answer your question, but does speak to their accuracy. My thinking is that you'll have to push that long heavy boolit awfully fast for it to stabilize in the 1 in 12" twist and that may be a bridge too far for a cast boolit. It should easily handle 200 to 210 grain cast projectiles such as the Lyman 311334 or 311299.
Imr 4831 will get you what your looking for except the subsonic part. Slow powder on that heavy boolit and slow twist should get you up to about 1400 ~ 1800 fps and stabilize. Like always work your load up.
Both my issy's had 1 in 12 with 303 bores, so if yours is like mine that 309 or 311 boolit isn't big enough. I had to have 314 boolits for accuracy.
I tried going slow in my Savage 30-06 with the Lee 230gr boolit and it did not shoot well until I hit about 1,800 fps. My rifle has a 1 in 10 twist.
It would be a pity if your rifle doesn't have the original .303 twist of 10in., which stabilized roundnosed jacketed bullets of 215gr. as that is what the Lee-Enfield rifles were designed for and the throat never altered, I believe, in British manufacture, and quite possibly Australian and American. I doubt if the difference between jacketed and cast will make an appreciable difference. The improvement in stability from increased velocity exists, but I also doubt if it will work without excessive pressure.
That is if your heavy bullet actually is inadequately stabilized, and it may not be. These things go by length much more than weight. Greenhill's formula, for bullets of about the specific gravity for jacketed, which is close to a typical good casting alloy, is that the rifling twist in calibres, multiplied by the bullet length in calibres, should be no more than 150, although in practice 200 sometimes stabilizes a bullet. A 12in. twist is about 40 times the bullet diameter, so it ought to work with a bullet close to four calibres in length, and perhaps with about five. There is also the likelihood that you would probably have a lube groove outside the case neck, which I don't like, or inside the powder space, which I really don't like.
I think really heavy bullets might be worth trying in a .303, although I can't see any real advantage over 215gr. But with the rifle you have, I would say it is only worthwhile if you can get a few bullets to try out, before laying out cash on a mould.
PM me with your mailing address if you want some Accurate Mold 31-245H to try. I have a few cast up, and would be happy to send you some.
I tried some of those Lee 230gr 300 blackout bullets recently, still cleaning the lead out of my mosin. It may or may not stabilize that long of a bullet at that speed, only way to find out is to try it. But the Lee is a 309 bullet, well supposed to be. Ones I was given were only 307, needless to say the .311 rifling did little to the bullet spin wise, just made a mess. Even if you got a Lee mold to throw some 309 bullets still may not get great results.
PM Sent, Bill*B
If you get a smaller bullet, onionskin paper, or beagling might be called for... Personally I'd go for onionskin, but i love the look of a white band separating my silver and brass!
I had several 30 cal rifles a 308 with a 1-12 to an 06' with a 1-8.5 (yes I know there's no such thing but I measured enough times to be sure) . The 308 without really driving it and even then a 180 gr even a RN of the same length of the 150 sp wouldn't shoot . A cast 175 gr PP would shoot at 75% of 180 jacketed data .
The NOE 311-230 fp currently in a GB is 1.59 in long ,which is 4.41 calibre in length I intend to shoot it in a 8.5 and 9" twist 30 cal I'm thinking about 22 gr of 4350 in a x39 will render all the case will hold and about 1300-1400 and fit in the magazine. The Savages have a very long leade so if it happens to fit in the magazine, I think the 06' will go out to something like 3.4 , I'm golden . I might not even need a rifle powder to hit the needed 1600.
I think even a 1-10 will be touchy with even the 230 as the 10 twist was for 225 RN .
The NOE boolit
http://noebulletmolds.com/smf/index....topicseen.html
I've shot 260 gr boolits in my 303 and they went nose first with no discernible yaw. But then they were smooth sides so the length for weight and circumferential mass would be more favorable. Unfortunately I didn't do any accuracy tests with them but 245 grain boolits shot pretty well. I wonder how the slower twist and shorter 225 gr would relate?