Im getting shoulder dents after firing. Im shooting an AR-10 308 Win using hornady 160gr FTX with IMR 4320 33.9gr seating at .035 under ogive.????

Im getting shoulder dents after firing. Im shooting an AR-10 308 Win using hornady 160gr FTX with IMR 4320 33.9gr seating at .035 under ogive.????
First issue is that bullet is NOT designed to be fired in 308 Win chamber. It is specifically designed to be fired in 30-30 Winchester lever action guns. The bullet ogive is not designed for the 308Win.

It is likely that you are under pressure and the next is not sealing so the chamber pressure is exposed to the shoulder and creates the dents.
 
The Lyman 49th edition starts you off at 42 gr of IMR 4320 where as the Hornady list it at 39,3 gr Start load. Neither really list his specific bullet choice. From what I gathered his bullet the FTX was designed more for a lever gun & pistols. Which looked to me like his choice was for a 30-30 Win. Being in the 160 gr. I know you can use components in different usages. But being new I try to stick with known loads for now.
The bullet was actually for a marlin- express. And i do think i was light on the charge is what created the dents. Factory loads have not done it.
 
The bullet was actually for a marlin- express. And i do think i was light on the charge is what created the dents. Factory loads have not done it.
I did have Marlin wrote earlier. Then changed it when someone mentioned it was for a 30 30. I thought I was wrong and didn't fact check either of us. Lol Just curious how do they shoot out of an AR ? Accuracy wise.
 
I did have Marlin wrote earlier. Then changed it when someone mentioned it was for a 30 30. I thought I was wrong and didn't fact check either of us. Lol Just curious how do they shoot out of an AR ? Accuracy wise.
not just for/in 30/30, but listed data from hornady in 300savage, 307win, 30rem ar and 308marlin. although designed for lever action w/tube mags it can be used in 7.62nato and 308win dbm fed. either go with next lower weight bullets (155's) and use starting charge or go up 1 (165-168's) and use the middle bottom half (lower 1/4) for starting charge.
 
Top