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Old 07-15-2019, 08:02 AM
Unclenick Unclenick is offline
Join Date: Nov 2010
Posts: 1,044

M2 Ball was loaded so the average round from a 24" test barrel with tight chamber tolerances ran about 2800 fps at the muzzle (as a Magnetospeed would measure it) and just under 2790 at 15 ft from the muzzle (as SAAMI standard practice would measure it) and 2740 fps at 78 ft from the muzzle (as the military spec has it measured; start screen at 6 feet and stop screen at 150 feet for the old vacuum tube detector coil type portable chronographs). These numbers are faster than most folks load for the Garand today. They were also measured with the cartridge handled so the powder was back over the flash hole, which maximizes peak pressure and velocity in the test gun (worst case pressure for someone firing uphill). You may get close to test barrel velocity with a new Criterion barrel or another match-grade barrel with a minimum length chamber. Worn chambers and throats won't.

The Garand typically throws powder forward against the bullet in flat firing and then has vibration settle it some. 25 years ago I intentionally fired some 1964 M72 NM ammo in several club Garands so the powder was at the back of the case. I fired them again with powder at the front of the case and they averaged about 80 fps slower. So keep powder position in mind when testing: only compare powder-over-flash hole velocities to the military velocity spec.

Incidentally, those old club guns had very worn barrels. The old NM ammo gave average powder-over-flash hole velocities of anywhere from 2495 fps to 2611 fps at 15 feet in the old guns (Oehler 35P) which would be about 2506 fps and 2622 fps extrapolated back to the muzzle. The NM ammo records show the 1964 load was 46 grains of IMR4895 and was rated 2669 fps MV from a test barrel (presumably extrapolated back to the muzzle from a lower 78-foot measurement). Still, it gives you some idea just how much difference the gun can make. I don't know what to allow for the age of the powder. Maybe nothing.

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Last edited by Unclenick; 07-15-2019 at 08:38 AM.
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Old 07-15-2019, 06:36 PM
.22shooter .22shooter is offline
Join Date: Mar 2010
Location: VA
Posts: 2,214

I used it fairly extensively with 110s around 2012/2013 during the panic buying. Worked just fine and produced 2MOA on average


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Old 08-13-2019, 08:00 PM
AllenGill AllenGill is offline
Join Date: Jul 2012
Posts: 50

Here are some data with Greek GI to compare:

M1 40.5 gr. AA2495
Mean 2343.4
Standard Deviation 45.9

Avg. Group Inches 4.125

M1 44.5 gr. AA2495
Mean 2532.7
Standard Deviation 24.6

Avg. Group Inches 4.25

M1 45.5 gr.IMR 4895
Mean 2648.5
Standard Deviation 28.8

Avg. Group Inches 6.25

M1 49.5 gr. IMR 4895
Mean 2832.1
Standard Deviation 38.4

Avg. Group Inches 3.5

M1 Greek
Mean 2715.5
Standard Deviation 31.0

Avg. Group Inches 2.5

The M1A liked it the best. It shot a 1.75 inch group at 100 yds using 168 gr. HPBT and a 6X scope. I misplaced the chronograph data, but it was very close to the chart velocity ~ 2700 fps range
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