Today I went to test the fps on some hand loads. Starting with the min load, I got 7 rounds into it and got a case stuck in my rifle and I can't pull the slide back. I took it to gunsmith, but it might be a couple days before I get it back.
What should I be looking for to prevent this from re-occurring?
I will provide some further details:
I hand-loaded 4 sets of 10 rounds of 300 AAC, 220 gr boolits, H110 powder
10 rounds with 6.7 gr powder (min charge from my load book)
10 rounds with 7.8 gr powder
10 rounds with 8.8 gr powder
10 rounds with 9.9 gr powder
Fired 6 rounds, chrono measured about 800 fps, which was what I expected based on the load book. It also didn't cycle the action completely, which I expected. After each shot I could see the bolt was partially pushed back but not far enough to eject the case and chamber a new round. Manually cycled with charging handle no problem.
On round 7 of the 6.7 gr loads, I felt the recoil, like the bolt didn't cycle into the recoil spring. Observing the rifle I saw an unusual amount of smoke coming from the rifle, around the bolt, even some black soot down into the magazine onto the other rounds. The bolt never moved. I believe all the smoke I saw normally would've rapidly escaped when the bolt cycles.
When I manually cycled the rifle after round 6 it didn't go fully into battery. I thought nothing of it at the time, and lacking a forward assist, I partially pulled back the charging handle and released it, and the bolt chambered the round fully. I don't know if that has anything to do with it. My experience is that it isn't unusual when manually cycling the rifle .
So now I can't budge the bolt. It is still fully forward. I can take the upper off the lower.
I have no idea what caused it. Did I damage the case at some point when I loaded that round? Is this "normal"?
If anyone has advice of what I can look for, what commonly causes this, and how to prevent I would greatly appreciate it.
Thank you