I got a Bushmaster stock set and lower parts kit at a gunshow.
I am building on a Rock River Arms lower
I have had two problems
1) The safety detent spring did not come with the kit.
2) The spring for the takedown detent does not fit the Rock River lower. I tossed on a caliper and it measures .104"
I understand the milspec on this hole is .097 max??
Other than that, everything fits and funcitons fine.
Assistance is appreciated.
PS. Been shooting bolt guns a LONG time. This is my first "serious" automatic. And my first AR.