Re: M1 grand in 30-06 load request
Memo43,
I recently acquired a Garand, and i feel your pain. I have done a lot of research (short of buying an older garand re-loading manual) and have developed an informed opinion (in my view) of how to reload safely for a garand.
During a lot of my research, i repeatedly ran across the following over-simplified advice;
1. "do not shoot bullets heavier than 180grains" and
2. "do not use slow burning powders in the Garand"
3. "lighter weight bullets in the 150gr range is ok"
The advice above center around the fact that the achilles heel of the garand is its op-rod.
Make sure you have the "77" oprod, also known as the oprod with the stress relief cut built into it. Unless you want the WWII era op-rod for collectors sake, i wouldnt mess with them as they are far more prone to bending than the re-designed op-rods.
With regard to the 3 items above, the fact is that modern, medium to slow burning powders can exceed the design limit of the op-rod even with loads well below max. This is true whether or not you are shooting a 150gr bullet or a 200grain bullet.
The garand's spec required that it launch a 150grain bullet at 2800ft/sec. At the time, some of the powders used to achieve this velocity was IMR4895, IMR 4064, and BLC(2). The muzzle pressure of the above powders are 8,650psi, 8,531psi, and 8,863psi respectively.
This tells me that if I limit the muzzle pressure to the above values, then i can safely operate my garand with any powder and bullet weight i choose.
I have also found that the reloading manuals out there for the garand are sooo conservative as to be unduly limiting of the capability of this rifle.
The Hornday reloading manual is a case in point...i have run some of the recommended loads through quickload, and the highest muzzle pressure corresponds to Reloader 15. I believe that it produces a muzzle pressure of around 8,300-8,400psi.
Personally, i have settled on Hogdon Bechmark as my go to powder for the garand. It is temperaure stable, and gives me the highest velocity for the minimum charge weight. I can launch a 175 SMK at 2700ft/sec, with a muzzle pressure less than 8,000psi. As you can see, this load is actually EASIER on my op-rod than the run of mill mil-surp ammo and recommended loads in some reloading manuals.
I have also loaded up some Varget behind the 175SMK...i used 49.5gr behind 175SMK and COAL of 3.24". Haven't chronoed this load, but the muzzle pressure is 8,286psi, and chanber pressure is 44,947psi.
Hope this helps.
