Question about AR-15 BCGs
Can you take BCG from a 5.56 and use it in a ar chambered for 7.62x39 or 6.8spc ?
0
-
You can use the Bolt carrier, but the bolt has to be changed for the different case head sizes. It is very easy, and straight forward. Pull the firing retainer pin, and the firing pin, then the bolt cam pin, and pull the old bolt out, put the new bolt in, replace the cam pin, firing pin, and firing pin retainer pin...2 minutes at the most. But NO, the 5.56 bolt head will not work with the 6.8 SPC, or the 7.62x39. I do believe that the latter two both have different head sizes and require separate bolts each. I could be wrong on that. 0 -
willonkauai,
Correct. The bolt itself is the only part which needs to be replaced because of rim diameter differences.
7.62x39 = 0.447" diameter
6.8 SPC = 0.422" diameter
Depending on the cost though some find it easier to replace the whole BCG as a matter of course. Six of one, half dozen of the other.
In ascending order of cost though, many folks just keep the complete upper on hand in order to just push the pins out and have a complete new upper in place.
Best.0 -
The spring and buffer may also have to be replaced, if so, a complete dedicated upper would be the best way to go - but I know how that goes - new uppers seem to attract new lowers. 0 -
quote:Originally posted by spirits
The spring and buffer may also have to be replaced, if so, a complete dedicated upper would be the best way to go - but I know how that goes - new uppers seem to attract new lowers.
Never seen one yet that has needed changed, in that area. The pressure is controlled by the size of the gas port in the barrel.0
Please sign in to leave a comment.
Comments
4 comments