I have a question for the learned AI experts to help understand an issue with my AXMC using my new 300 WM bolt.
I configured the MC with the new bolt body, a new AI 300 PRC barrel, and a new magazine that has been tuned for 300 PRC (red follower). I went to zero it today. The rifle performed well in terms of accuracy. I had it zeroed in 3 shots. I used Hornady 300 PRC ammo with the 225-grain bullet. Before I began the process, I loaded the magazine, put the safety in the middle position, and cycled the bolt to check feeding and extraction. All of the rounds loaded and extracted perfectly. The bolt ran smoothly during chambering and extraction.
I then began the zeroing process. I fired one round, and was pleasantly surprised that the POI was minimally different than when shooting .308. Here is where the issue began. After firing, cycling the bolt required considerable force to open it fully. It went up to a point close to the top, but then required excessive force to lock it in the open position so I could extract the fired cartridge. I fired a total of 15 cartridges. All required extra effort to lock the bolt open, so it could extract the round. Some required more force than others.
I measured fired and unfired cartridges, and dimensionally, they were almost identical. The only measurement that was different was the diameter of the neck. An unfired case measured 0.338" while the fired case neck diameter measured 0.345". I don't know if that is normal since I don't reload.
Any thoughts?