Phantom30
09-05-2016, 10:40 AM
A while back I was chasing 60gr 22LR Subsonic PC reloading ideas down the proverbial rabbit hole. Popper suggested I try the Hodgdon Trial Boss and with a 55gr bullet and call it a day. Ok, that was a simpler solution. But, then you could just buy Beck / RTB ammo 75gr, 1010fps, for 70 cents a round but that requires a 1:7 twist barrel. Well, since I have a few AR Stoner barrels all with 1:8 twist not so good for me. So could a 556x45 boolit be designed for the PC process to support subsonic and supersonic performance? This is what I came up with. A 77-80gr boolit that should work. But the cost to buy the custom mold from Lee has a $175 setup cost plus. But you can get a six cavity mold in the end. Accurate Molds, has a tip size limit of 0.18 so that’s not an option either.
175891
The difference between the SAAMI and the NATO chambers is definitely interesting for the PC’er. I don’t think I’d be using PC with a 223 Rem barrel, the short narrow throat could be problems with a 225 sizing die. So I went with the Reimer data for NATO barrels, the throat relief makes nice for PC process. Even with that barrel you can get in trouble with the ogive at max COALs. SO with this design, shortening the COAL gave a 0.0006 jump clearance with a max PC thickness of 0.0025 and 225 sizing on the drive bands. Greenhill formula for this boolit is 8.1 twist so my barrels should be good to go. This design should be a great application to try out Dutchninja’s BBDT process on. Like to stand up a few hundred Kawasaki green bullets in that baking grid. Just have to convince myself it’s all worth the setup fee with Lee. Better ideas, comments etc.
175891
The difference between the SAAMI and the NATO chambers is definitely interesting for the PC’er. I don’t think I’d be using PC with a 223 Rem barrel, the short narrow throat could be problems with a 225 sizing die. So I went with the Reimer data for NATO barrels, the throat relief makes nice for PC process. Even with that barrel you can get in trouble with the ogive at max COALs. SO with this design, shortening the COAL gave a 0.0006 jump clearance with a max PC thickness of 0.0025 and 225 sizing on the drive bands. Greenhill formula for this boolit is 8.1 twist so my barrels should be good to go. This design should be a great application to try out Dutchninja’s BBDT process on. Like to stand up a few hundred Kawasaki green bullets in that baking grid. Just have to convince myself it’s all worth the setup fee with Lee. Better ideas, comments etc.