There have been some issues with mismatched firing pins and bolts. If this is a 6.5 Grendel bolt Alexander Arms uses a .136” bolt face depth. Typical 223/5.56 bolt has a .125” bolt face depth with a bolt length from tail to the face of the lugs of 2.80”. Alexander Arms lengthened the bolt to 2.810 to permit the use of standard length milspec firing pins.
The spec for firing pin protrusion on an AR-15 is .028” minimum and maximum .036”. A couple of bolt manufacturers used 2.80” length bolt with a standard length firing pin which resulted in pierced primers. Some manufacturers have switched from .280” length bolt to .281”. It is just best to measure your firing pin. Most information I find list a milspec firing pin at 3.277 to 3.279. You could have tolerence stacking where you have a long bolt and short firing pin.
Here is a thread where I measured all my bolts and firing pins to give you and idea of the manufacturing variances.
http://www.65grendel.com/forum/showthrea...ment/page2
The spec for firing pin protrusion on an AR-15 is .028” minimum and maximum .036”. A couple of bolt manufacturers used 2.80” length bolt with a standard length firing pin which resulted in pierced primers. Some manufacturers have switched from .280” length bolt to .281”. It is just best to measure your firing pin. Most information I find list a milspec firing pin at 3.277 to 3.279. You could have tolerence stacking where you have a long bolt and short firing pin.
Here is a thread where I measured all my bolts and firing pins to give you and idea of the manufacturing variances.
http://www.65grendel.com/forum/showthrea...ment/page2