[pahrumpcaveman]

I have my first garand on the way from the CMP and have been reading up on the reloading particulars for this weapon . Does anyone know what the actual pressure is supposed to be at the port to prevent OP rod damage ? I ask this because if I run a proven " Garand safe load " through my QuickLOAD program I can adjust different load combinations to match that pressure curve and the pressure at the port . Example , if the port pressure is supposed to be 12,000 psi and the port is at 18" ( I'm not sure of this 18" as I don't have the gun in my hand to measure where it actually is ) I can adjust the pressure curve to match . Or am I way off base and about to kill myself and anyone within 20 feet of me ???

[critter]

Can't help you with those numbers except indirectly. The G usually runs beautifully with bullets of 150-165 gr and moderate loads of IMR 4895. You might run a load of 150gr bullet and about 46 gr IMR 4895 through your program to see what pressures are 'nominal'.

BTW, check the above as they are from memory!--but stick to the 150 gr bullets and moderate loads of IMR 4895 (or powders in that burn rate range) and no harm will come to you or your M1.

Good luck. They are a ball to play with!

[pahrumpcaveman]

Critter , Interesting comparison of loads here . Your load of 46 gr IMR4895 , under a Sierra 150 gr MK #2190 , OAL of 3.250 , est. vel. 2433 fps , gives a pressure of 17,238 at 14 " in the barrel . 46 gr of IMR under a 168 gr Sierra MK#2200 , OAL 3.285,est. vel of 2412 fps , gives 17,652 at 14" . This would lead me to believe that a load of 39 gr of H4227 under a 110 gr Sierra HP # 2110 , OAL of 3.100, est. vel of 2798 fps and only 15,166 psi at 14" should be safe to shoot in the old Garand without fear of OP rod damage . Cant wait to pop a coyote with it . :D :D (Just hope it feeds )

[30Cal]

The gas port as at 18 or 19". You should be able to get a 150gr bullet to about 2900fps with the usual powders--4895, 4064 and others in that range.

I'd put more stock ina chronograph than in a computer simulation. Powder burn rates can and will vary quite a bit from one lot to the next.

[pahrumpcaveman]

Oh I agree . I will certainly be shooting these loads over my chrono .

[Khornet]

but isn't it also somehow a matter of the timing, that is WHEN the peak pressure occurs?