Paco
Well-Known Member
Remove BCG from upper.
Ensure bolt is extended
Place BCG bolt first onto a flat surface (BCG is vertical)
If BCG does not collapse under its own weight, gas rings are good. If it collapses, replace gas rings.
Both my 300blk and 5.56 SBR uppers have already worn out their gas rings. Apparently suppressed full-auto eats gas rings like candy.
Ensure bolt is extended
Place BCG bolt first onto a flat surface (BCG is vertical)
If BCG does not collapse under its own weight, gas rings are good. If it collapses, replace gas rings.
Both my 300blk and 5.56 SBR uppers have already worn out their gas rings. Apparently suppressed full-auto eats gas rings like candy.