Primers backing out on virgin Hornady brass
Hi fellas.
I just recently got my 6CM together and I am having some odd issues that I wanted to air out here and hopefully get some advice for.
The rifle:
Surgeon 591R
Bartlein Remington Varmint profile, 8 twist, finished at 26", 11* target crown, no brake
In my quest for Winchester brass, I have come up blank, and have for months now, so I was forced to buy Hornady brass, as that was basically all I could find available.
I was fortunate enough to have Joe return my phone call and give me some load data for fire forming (among other good info), and he indicated I should load up the 105 Hybrids @ .010 jammed, with 48 grains of H-1000 for fire forming and then bump that up to 49 grains of H-1000 with an .040 jump once I had my brass formed. He indicated that should be my go to load and get me close to 3200 fps with my set up.
On the first day out shooting this jewel, I experienced amazing accuracy while fire forming, but nearly every piece of brass came out of the gun with the primer sticking half way out of the primer pocket. No other signs of pressure were present. No hard bolt lift, and the primers did not look overly flattened. This was virgin brass before I started.
To be clear, the load data was as follows: 48.0 gr H-1000, Berger 105 Hybrid, Tula KVB-762 Primers.
Cartridge Data: 2.217" to Ogive 2.817" OAL (.010 Jammed)
The average speed was 2922 FPS over 10 rounds. It was 54.5*f , 29.03 in/hg and I was at 1050 ft ASL.
I came home from that range trip, cleaned, sized and built some cartridges using Federal 210M primers and 49.0 grains of H-1000 thinking that perhaps the Tula primers were an issue, even though I have loaded thousands of them in 308 with ZERO issue, and as good or better than 210M ES/SD results on average. I also reamed the case mouths, and trimmed to length per Joe's recommendation using the Forster .243 neck reamer BEFORE I sized the brass.
The new cartridge data was as follows: 49.0 grains H-1000, Berger Hybrid, Fed 210M Primers. 2.181 to Ogive, 2.791 OAL (.040 jump)
As a side note, I also loaded up 20 rounds using the exact same data but with CCI BR2 primers as a test.
At the range, the (accuracy) results were amazing. I netted an additional 70 FPS, but was well short of the 3200 FPS I was expecting to see based on the conversation I had with Joe, but after my fire forming results, I knew I was not going to get anywhere near 3200 fps with this rifle. The real problem is that the primers were again backed out of the pockets, but not nearly as far, and not every piece of brass was affected this time. I would say about 2/3 of the total shots fired, exhibited proud primers, and they were sticking out of the pocket about .020 at the most.
Atmospheric data for the day was: 68.9*F , 29.1 in/hg and the same 1050 ft ASL.
Anyway, that is as clear as I can be fellas. I will say that I called Hornady and have a box of the brass that I purchased heading their way now, along with 5 pieces of my once fired brass for them to look at. It will take weeks before I get an answer from them, so I figured I would ask you guys what you thought.... Please let me know...
Respectfully,