30 XCB in the M1a?

[Silvercreek Farmer]

I’ve seen it mentioned a few times but not much on results.

[barkerwc4362]

So is this the 30x57 version? Remember the M14/M1A is limited by magazine to a max OAL of just over 2.8. I load my 175 grain Noslers to on or about 2.810. This is with a 51mm case. The 57mm case would be about another 1/4" longer. I have shot cast in my 308 Garand, but don't remember what my cartridge OAL was with the RCBS 200 grain silhouette bullet.
Bill

[Ford SD]

I’ve seen it mentioned a few times but not much on results.

i was planing on doing some during the summer ... but did not get around to it..... cast a big bunch and use it for everthing

M1a =1/ 10/11 or 12 twist so only so fast you can push it

powder = only some powders work with the pressure/ time curve you need

i have shot the rcbs 165 sil out of a m1a

if hunting i would go with the 311/312299 = more weight = more energy


the only way you would get a improvement long range is .... which one has the better bc?

[oldblinddog]

I don’t have an M1A but I shoot the xcb pretty fast out of 1-10 and 1-12 twist rifles in .308. I would use RL22 and or Accurate 4350. RL22 at 47.0 grs. should get you 2300 FPS with about 1 moa accuracy. I load them to just touching the lands with this. Cases are Remington, primers are Remington 9 1/2. Load is not max but start at 43.0 and work up looking for an accuracy node in your rifle.

A4350 at 47.0 grs will give you more velocity but not as good accuracy. I think Larry Gibson gets about 2 moa out of that load.

No clue if these will cycle the action or be too much for the action. But, you can’t get enough of these slow powders into the case to overpressure the case. You will just run out of space.



The first is a 20” Remington barrel 1-10”, the second is a 26” Krieger barrel. I have rifles with 1-12” and 1-17” twist, but don’t recall now which that one is. Either will shoot 1 moa, however.

Sort your bullets for weight.

Edited to add: That second target is from the 1-17” twist rifle.

[charlie b]

I shoot them out of my Garand. At around 2000-2100fps they cycle the action and get groups as good as I can hold with open sights (2-3MOA).

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[Winger Ed.]

Put "30 XCB" in a search engine.

An amazing amount of info. and old forum discussions will pop right up.