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Art Eatman · August 15, 2000, 09:40 PM

BottomGun, that sounds like a bit hot for the Garand. It's possibly hard on the operating rod.

The load itself is okay; I've been using 52.5 grains of 4064 behind a 150-grain bullet for 50 years, now.

Everything I've read, and a lot of knowledgeable folks on TFL, talk of using a bit faster burning powder, and holding chamber pressures to around 47,000 psi (design pressure). I'd guesstimate your load at around 49,000 to 50,000 psi.

The Garand is designed for 2,000 psi at the gas port. Over that, it's hard on the operating rod. Slower powders than 4895 tend to maybe be noticeably higher at the gas port, so I've read.

I'd guess that the M1A is similarly designed, insofar as pressure (?). I'd use a 110-grain bullet, and with 4895, some 200 ft/sec under whatever the loading manual says is max. Dunno; FWIW, the .308 factory loads were shown as having a chamber pressure of 53,000 psi in the early days of that cartridge.

Hope this helps, Art

[This message has been edited by Art Eatman (edited August 15, 2000).]

August 15, 2000, 09:40 PM	#3
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	BottomGun, that sounds like a bit hot for the Garand. It's possibly hard on the operating rod. The load itself is okay; I've been using 52.5 grains of 4064 behind a 150-grain bullet for 50 years, now. Everything I've read, and a lot of knowledgeable folks on TFL, talk of using a bit faster burning powder, and holding chamber pressures to around 47,000 psi (design pressure). I'd guesstimate your load at around 49,000 to 50,000 psi. The Garand is designed for 2,000 psi at the gas port. Over that, it's hard on the operating rod. Slower powders than 4895 tend to maybe be noticeably higher at the gas port, so I've read. I'd guess that the M1A is similarly designed, insofar as pressure (?). I'd use a 110-grain bullet, and with 4895, some 200 ft/sec under whatever the loading manual says is max. Dunno; FWIW, the .308 factory loads were shown as having a chamber pressure of 53,000 psi in the early days of that cartridge. Hope this helps, Art [This message has been edited by Art Eatman (edited August 15, 2000).]