1907 Palma Cartridge for Camp Perry

[madsenshooter]

I researched nitroguanidine used as a flash suppressant and found that in order for things to work right, the nitroquanidine has to be first thing burned. The gases generated by it keep the gases generated by the nitrocellulose from flaming. Trouble is, the nitroguanidine is hard to light. I found that it burns best at a specific temperature, very nearly the same temperature that high nitroglycerine powders burn at. So I put a small amount of large flaked high nitroglycerine powder at the bottom of the case with the IMR 7383 on top of it. The unburned granules went away and the smoke that came out the barrel was grey rather than black. Pressure was just at the blow alloy back on the caseneck level. With the alloy I'm using that has been around 36,000psi, so I'll load some more with a little less of the booster charge. In the meantime, my local club has a 50rd match in a couple weeks, so I'll go ahead and load the rounds for it and Camp Perry with RL19.

[madsenshooter]

I'm still at it. I've worked my way down with the 10B101 booster and IMR7383 main charge to the point that I'm right on the borderline of my alloy's ability to handle the pressure. I shot six today, three of them blew alloy back on the caseneck, three of them didn't. I shot one, made a sight adjustment, and put five in a 1.9w x 1.0t, 100yd group with the rifle I plan on using at Camp Perry. That's as good as or slightly better than I ever got with Nosler 168gr match bullets. Down another half gr on the total charge should do it. The full length rifle has a tighter throat than the cutoff, I had no sign of alloy failure from a load that was one step higher shot from the cutoff.

[madsenshooter]

Ah, I see why three blew alloy and three didn't! There were two groups of cases with a weight difference of 3 grains between the groups. I already tried going down .5gr from the above load, with the same cases. No alloy blew from either group, but the shots were wider and the difference in point of impact for light vs heavy cases more apparent. I'm going to weigh cases and go back to that previous load using some of the lighter ones.

[madsenshooter]

7383 testing suspended, I decided to split the difference between the loads shown in post #6 and go with 38.7gr of RL19. That might not give me the 2150fps quickload predicted for 39.5gr, but I thought it prudent to cut back a tad for the higher temps of July. I had hoped to establish a 200yd zero at a local club this weekend, but unfortunately can't afford to go. But, I have a good 100yd zero using a six o'clock hold. Running a ballistic calculator says that should roughly translate to a center hold at 200yd. I see why they decided to use this weight spitzer bullet at 2150fps back in 1907, it's still supersonic at 1000yd. BC of my cast bullet must be over .500.

[madsenshooter]

The load didn't work out too well at 200 yds. I had a lot of bullets impact on the target in places other than where I was aiming! Though I'm not the world's greatest highpower shooter, I do have a sense for where the rifle is pointed when the striker falls. This year's score was 230-2X, down 20 points or so from last year. I'll move on to a better alloy that weighs a bit less, 190-195gr, shoot about the same speed, and forget about duplicating the Palma round. I still wish to shoot cast, since I can no longer afford those expensive match bullets.

My Garand, on the other hand, was shooting very much to point of aim and I wound up with a 267-7X. Nine of the fifteen slow fire prone shots were Xs, if I count the four sighter shots that were X, and my slow fire prone score was 97-5X. Then I stupidly loosened my sling one notch before shooting the rapid fire string. That changed my cheek weld and the point of impact, group was high right and score was 88. I wound up mid-pack in the unlimited Garand. Lesson learned, when you're shooting 10s and Xs, don't change nothing! I know what notch the sling was in when I was hitting, the sight hasn't been moved, just wait till the next match!

[psteinmayer]

You should have heard Bob muttering while he was walking back to the car! LOL Just kidding Bob...

You shot much better than I did this year. I only had a 186 with my Krag (83 prone-slow, 53 prone-rapid, and 50 off hand). I was having trouble getting my sights back on target during the rapid string. I have a spare 1902 rear sight, and I'm going to enlarge the peep slightly, and see if that helps.

My Garand was also much better, but not on par with Bob's... I had a 240: 90 prone-slow, 90 prone-rapid... and then 60 off hand. The wind had kicked up and between the rain and wind, I was having a heck of a time holding steady in off hand. Next year, I'll have a proper shooting jacket, and that should help with my off hand scores!