I have been getting slight primer cratering (CCI #41 primers), ejector marks/swipes, and an indented ring just inside the rim of the casing using one lower (M&P15) as well as ejector marks/swipes with a second lower (80 percent) with both my uppers (18" B.A. Barreled upper/ 20" WOA SPR barreled upper) with both my reloads and factory ammo. I have tried 3 BCGs as well as swapping the bolts and bolt carriers between the 3 with no changes. My bolts are: JP enhanced bolt (I have 2), BCM bolt. My bolt carriers are: JP FMOS, BCM, Aero Precision. All Combinations have been headspace checked in both uppers with both a go/no go with all having the proper headspace. it doesn't matter if my reloads are at the minimum suggested charge weight or the maximum suggested charge weight for whatever powder I'm using I get slight cratering/ejector marks/swipes, indented ring just inside the outer rim in both uppers with my M&P15 lower and ejector marks/swipes in both uppers using my 80 percent lower. I have tried swapping out my upper receivers with spare ones I have lying around with both uppers, swapping out my triggers with multiple different triggers I have both Milspec and expensive triggers (triggertech diamond, having the pull weight set on the lighter end or on the heavier end) with no changes. Does anyone know what would cause this or why I can't fix the issue? is it important? I know ar15s can be hard on brass, but I was hoping to at least not have the primer cratering and /or ejector marks/swipes, so I can use getting them along with my velocities to check if I'm getting pressure signs. and as far as the indented ring around the inside of the rim I have no clue what would cause that. If anyone has any thoughts on this or advice on what to do to remedy my issues, please let me know. If you need more information let me know so I can give you that. I have pictures posted that vie labeled so you know what's what.
Thank you,
Justin Bullock
Thank you,
Justin Bullock
