Clarence: I think I miss spoke in my post in regards to whether the barrel was chambered with a .136 bolt and them used a .125 bolt. A .125 bolt would reduce the available room and may not chamber a round. If the round did chamber the bullet could be stuck in the lands significantly raising pressure. If unsure which bolt the barrel was chambered it’s best to consult the manufacture or use a set of go,no go gauges.
If the barrel was chambered using a .125 bolt and you switched to a .136 bolt +.001 or -.001 you have more additional room and could have excessive head space. Excessive head space would tend to blow out the shoulder, probably shortening the life of the brass and might eventually lead to a case head seperation. Ultimately just know which bolt your barrel was chambered to use!
The problem arises that certain manufactures/vendors have deviated from the norm and chambered barrels with .125 bolt face depth X39 bolts. The consumer needs to do a little research when buying any variant chamber for the AR-15 as there can be certain pitfalls. I think it’s even worse if you delve into the large frame AR-10 7.62/6.5 CM/260.
Ultimately just know which specific bolt your barrel was chambered. It’s not a bad idea to have a spare bolt and an extra extractor as the extractors are not inter changeable. The 6.5 Grendel bolt takes a 6.5 Grendel extractor.
If the barrel was chambered using a .125 bolt and you switched to a .136 bolt +.001 or -.001 you have more additional room and could have excessive head space. Excessive head space would tend to blow out the shoulder, probably shortening the life of the brass and might eventually lead to a case head seperation. Ultimately just know which bolt your barrel was chambered to use!
The problem arises that certain manufactures/vendors have deviated from the norm and chambered barrels with .125 bolt face depth X39 bolts. The consumer needs to do a little research when buying any variant chamber for the AR-15 as there can be certain pitfalls. I think it’s even worse if you delve into the large frame AR-10 7.62/6.5 CM/260.
Ultimately just know which specific bolt your barrel was chambered. It’s not a bad idea to have a spare bolt and an extra extractor as the extractors are not inter changeable. The 6.5 Grendel bolt takes a 6.5 Grendel extractor.