I’m new to ARs and this is my first post. I just purchased a s&w sport. Shot 120 rounds though it a couple weeks ago and it ran great. Earlier today, I finally got a chance to clean it. I disassembled the bcg and cleaned and relubed all the parts.
Question I have is before I disassembled the bcg the bolt assembly moved freely in the bcg. When I cleaned and lubed everything and out it all back together the bolt assembly is very tight going back in and doesn’t move that freely in the bcg anymore, is this correct or did I do something wrong?
I put every back together and everything seems to be functioning correctly, but I’m worried that the bolt being stiff will cause problems. Any help will be much appreciated.
It’s supposed to be tight enough that if you stand the BCG up bolt down, bolt extended, on a table that it doesn’t collapse. If that’s about how “tight” you mean, then it’s GTG. Assuming everything’s assembled right.
You may want to read the 23&P chapter on testing gas rings. The gas rings should support the weight of the bolt, not the bolt carrier.
b. Install bolt assembly (1) into key and bolt carrier assembly (3). Check for worn rings by holding the key and bolt
carrier assembly (3) with the bolt assembly facing down. If bolt assembly falls out after firing pin retaining pin (4) and
bolt cam pin (5) are removed, the rings are worn. Evacuate to support maintenance.
What made the bolt hard to re-insert in the carrier is the gas rings. They spring apart a little when the bolt is removed from the carrier. Once re-inserted, it’s gonna feel tighter than before, because the human mind can play tricks on itself. Your first thought is “Yikes! That went in too tight! Did I mess something up?” Then you look for the slightest sign that you did.