140fps makes a difference

[D.B. Cooper]

What a difference 140 fps makes. I was just out evaluating a couple of loads for my Garand for Service Rifle. The first was 47.4 grains IMR 4895, which is from Master Po's data. It held the black (6MOA) on an SR-1 reduced target and averaged 2605 fps. The second was 44.8 grains IMR 4895, which is middle of the road from Hornady's M1 Garand specific data. It held the 10-ring (3.25MOA) on the same target, but it also had significantly less recoil. The change in accuracy doesn't surprise me, but the reduction in felt recoil does.

Given that mil-spec M2 ball ammo was 2500 fps, and this lower charge came in at 2465, I think I'm going to stick with it. However, I ran these with PPU 145 grain FMJ with a flat base, which I am now out of, so the next batch will have to be Hornady 150 grain FMJ with a boat tail, of which I still have about 200. I hope that doesn't negatively impact the results. I'm a little concerned as everything firearm related is pretty much out of stock now.

 

[Blue68f100]

I have never got FB vs BT ever like the same load. Different profile, different length, require a different charge.

Some times you find a bullet/powder combo that has more of a push vs a sharp recoil.

 

[GooseGestapo]

The Hornady 150gr .308” FMJ is a good bullet for what it is, but is basically a “blasting” bullet.

If you want ACCURACY, use the 155gr ELD-match.
My first Garand Match, I medaled using the155gr A-max (discontinued) over 48.0gr H4895 in my CMP-Special w/Criterion barrel. Next match, with 150gr FMJ, I finished in the middle of the pack...

My as issued ‘43 O3A3 w/2groove barrel .05/0 bore and throat shoots the Amax like this:
Garand almost. Shot to left was before 2clicks right (100yds). The FMJ will shoot 1.5 moa, the Amax, half or less.

 

[748]

Yeah I have seen this when 30-30 loading, give up 100 to 200 fps and lose and inch or 2 off groups. But your still at 4 moa on a good day.

 

[D.B. Cooper]

The Hornady 150gr .308” FMJ is a good bullet for what it is, but is basically a “blasting” bullet.

If you want ACCURACY, use the 155gr ELD-match.

I also have to take the rifle for what it is. It has a 1956 S.A. USGI barrel. Stock is new from DuPage, but it's an entirely as-issued rifle. (Service Grade from DCM. DCM, not CMP.) And I prefer to keep it that waym, even though it's a "shooter" grade gun.

 

[D.B. Cooper]

Yeah I have seen this when 30-30 loading, give up 100 to 200 fps and lose and inch or 2 off groups. But your still at 4 moa on a good day.

Funny you would mention 30-30. As soon I was done with the M1, I switched over to a 30-30 lever gun with Rem CoreLokt 170 grain. Just zeroing for moose season. It recoils more than the M1! (My shoulder is a little sore today. LOL)

 

[climbnjump]

It held the 10-ring (3.25MOA) on the same target, but it also had significantly less recoil. The change in accuracy doesn't surprise me, but the reduction in felt recoil does.

P-Max of the first load is around 37k psi and the second is around 32k psi. That's pretty significant. Based on the numbers and the type of action on a Garand, I guess I'm not surprised at the reduction in felt recoil.