I took my new RRA M4 configuration rifle out to the range today, and was very happy with its performance, with one exception. The pins on my FSB worked themselves out; one fell all the way out and landed on the floor under my bench. Now I have not contacted the manufacturer of the barrel yet, so I don’t want to say who made the barrel, but it was not RRA. Only the lower receiver on this rifle, parts kit, and bolt are RRA. I have three other AR’s and have shot thousands of rounds through AR’s, and M16’s, and have never had this happen before.  One more interesting thing I had happen today; I took my bolt group apart, RRA, and found what I believe to be some sort of “O” ring around the extractor spring. When did RRA start shipping these on their extractors?
MB

Never seen that before.  I agree on the brute force approach - just pound it firmly back in there.

Just leave them out. Your rifle will be fine.

Whoever installed the barrel probably put that pin it, and intended to home back and pound it home and seat it, but forgot to finish the job.

If you are going to do it, be sure to have it properly braced so you don't whack the FSB into a canted position.

You need a new digital camera or use Macro Mode.

Quoted: You need a new digital camera or use Macro Mode.

Excellent point.  A new camera would have taken care of it.

CHRIS

well it looks like the fsb pins issue has been covered. so as far as the o-ring, alot of people add them in lieu of the defender. My RRA bolt did not come with the o-ring, however I know that the WOA bolts from ADCO come with the o-ring installed.

Quoted: Just leave them out. Your rifle will be fine.

+1

They are dead weight!  Replace them with plastic ones from Magpul!

Quoted: Quoted: Just leave them out. Your rifle will be fine. +1 They are dead weight!  Replace them with plastic ones from Magpul!

w00t!  going to the Magpul site now to order some hope they have them in orange

Thanks guys,
I braced my barrel and hammered the pins back in. I will test the rifle next week at the range.
I am going to check into the plastic pin thing and see if I can get some ordered up. If not I may try super glue.
MB
Sorry about the crapy pictures, I should have shot them in macro mode.

Quoted: Quoted: Quoted: Just leave them out. Your rifle will be fine. +1 They are dead weight!  Replace them with plastic ones from Magpul! w00t!  going to the Magpul site now to order some hope they have them in orange

I just sent the design to Lumpy. Maybe he can make it better!