Short version for anyone who doesn't want to read the several paragraphs below. I want to take my Garand hunting again and .30-06 ammo is nowhere to be found. I have plenty of 150 gr and 165 gr Nosler ballistic tips, so time to load. I'm trying to decide between H4895, IMR 4320, Superperformance and IMR 4350. I'm also wondering the best procedure for testing my handloads. I'm leaning toward using IMR 4320 as the powder, shooting test loads with the gas plug open, and then adjusting the gas plug and shooting groups to confirm accuracy of my best test load. I'm leaning toward IMR 4320 because I have several pounds, I am unlikely to use it for anything else, and it is the next fastest burning powder I have in stock (after H4895). My H4895 is useful in a wider variety of cartridges, so I'd rather not use it here.
Long version: Hodgdon lists Garand service rifle loads for 150 gr Nosler ballistic tips with Varget, BL-C(2), H4895, IMR 4064, IMR 4166, and IMR 4895. Unfortunately, H4895 is the only one I have in stock and the difference between Hodgdon's starting load and max load for the 150 gr Nosler is 0.1 grs (46.0 and 46.1)! They do not publish a load with 165 gr Nosler ballistic tips. Also, the velocities for their published service rifle loads with H4895 are unimpressive (2,810 fps) with the 150 and 2,676 with a 165 gr Sierra.
So, I guess I'm going to use the Schuster plug. I have two questions.
1. Which powder to use? In addition to H4895, I also have Superperformance and IMR 4320 which both are very good for .30-06. I also have a lot of IMR 4350. I could go with H4895, but the velocities aren't that great. Superperformance and 4320 offer higher velocities and I am unlikely to use them in any cartridge besides the .30-06 whereas H4895 and IMR 4350 are very useful in my other cartridges.
2. What procedure to use when testing groups. I see three ways to do it.
a. First, I could shoot my test loads checking for best group with the gas plug "open" so that the rifle operates like a bolt rifle. Then load more of the charge that produced the best group. Shoot several to adjust the gas plug so it cycles properly and then shoot groups to check the accuracy of that load. Downside to this method is the chance that my best load when the Garand is operating as a single shot may not produce the best groups when the rifle is shot as a semi-auto.
b. Load extra test loads of the heaviest charge I am going to test. Adjust the gas plug so that the rifle cycles with the heaviest charge and then shoot my test loads with the rifle operating as semi-auto. The advantage to this is that I will see how the "hot" loads group as semi-auto. The downside is that I expect at some point as I work my way to lower charge weights the rifle will no longer cycle properly and then I'll be back to working with the single shot.
c. Load extra test loads of the lightest charge I am going to test. Adjust the gas plug so that the rifle cycles with the lightest charge and then shoot my test loads with the rifle operating as semi-auto. This is safer in the sense that I would be shooting my lightest loads first and working up. The downside is that I will be putting progressively more pressure/velocity on the op-rod as I work my way up.
Long version: Hodgdon lists Garand service rifle loads for 150 gr Nosler ballistic tips with Varget, BL-C(2), H4895, IMR 4064, IMR 4166, and IMR 4895. Unfortunately, H4895 is the only one I have in stock and the difference between Hodgdon's starting load and max load for the 150 gr Nosler is 0.1 grs (46.0 and 46.1)! They do not publish a load with 165 gr Nosler ballistic tips. Also, the velocities for their published service rifle loads with H4895 are unimpressive (2,810 fps) with the 150 and 2,676 with a 165 gr Sierra.
So, I guess I'm going to use the Schuster plug. I have two questions.
1. Which powder to use? In addition to H4895, I also have Superperformance and IMR 4320 which both are very good for .30-06. I also have a lot of IMR 4350. I could go with H4895, but the velocities aren't that great. Superperformance and 4320 offer higher velocities and I am unlikely to use them in any cartridge besides the .30-06 whereas H4895 and IMR 4350 are very useful in my other cartridges.
2. What procedure to use when testing groups. I see three ways to do it.
a. First, I could shoot my test loads checking for best group with the gas plug "open" so that the rifle operates like a bolt rifle. Then load more of the charge that produced the best group. Shoot several to adjust the gas plug so it cycles properly and then shoot groups to check the accuracy of that load. Downside to this method is the chance that my best load when the Garand is operating as a single shot may not produce the best groups when the rifle is shot as a semi-auto.
b. Load extra test loads of the heaviest charge I am going to test. Adjust the gas plug so that the rifle cycles with the heaviest charge and then shoot my test loads with the rifle operating as semi-auto. The advantage to this is that I will see how the "hot" loads group as semi-auto. The downside is that I expect at some point as I work my way to lower charge weights the rifle will no longer cycle properly and then I'll be back to working with the single shot.
c. Load extra test loads of the lightest charge I am going to test. Adjust the gas plug so that the rifle cycles with the lightest charge and then shoot my test loads with the rifle operating as semi-auto. This is safer in the sense that I would be shooting my lightest loads first and working up. The downside is that I will be putting progressively more pressure/velocity on the op-rod as I work my way up.