06-11-2013, 11:40 AM
If you are breaking off the same lug there might be an issue with the barrel extension. Can you try a different carrier and cam pin with your new bolt. It might be that you are not getting a 100% lock up of bolt lugs to the extensions lugs. A new bolt should wear evenly on all lugs except the one across from the extractor. this one should make little or no contact. Are you resizing your brass correctly so the bolt can lock up freely. Take the upper off to do this test. Put your resized case in the chamber and push the carrier with your thumb to close the bolt so it's flush with the back of the upper. Now pull back on the charging handle to eject the case. If it pulls back with normal pressure then your cases are resized properly. If it pulls back very hard or locks up tight you have to set the case shoulder back so the bolt works freely. Your bolt may not lock up right if the cases are to long to chamber easily. This puts a lot of stress on the lugs as they might not get 100% contact.
Greyfox
Greyfox