Anyone know the exact size and thread count? I seem to have lost one? It is an Armalite lower if that helps...

Sorry don't know the specs, but their all the same, simply pull one outta your "Field Repair/Spare Lower parts kit", something no AR15 owner should be without.....

Bushmaster sells good ones, as does DPMS.

Mike

1/4" x 28 pitch on the threads.  

Some one else will need to give you the needed lenght of the bolt.

Quoted: "Field Repair/Spare Lower parts kit", something no AR15 owner should be without..... Bushmaster sells good ones, as does DPMS. Mike

Yet another thing I will need I guess>

With all the parts on AR15 rifles that tend to zing off into the nether regions, like the buffer detent pin and spring, the pistol grip spring, the firing pin retaining pin, not to mention the weakest link that extractor and extractor buffer and spring, NOT having spare AR parts handy can mean the difference between having one bad SHTF rifle or a danged expensive aluminum baseball bat (actually a real bat would better as ya can grip it).

Food for thought, eat up!
Mike

added: forgot to mention, some of the items above will literally do what your mom always warned ya about "put your eye out"!, if you ain't careful, and anyone who's spent more than an hour on your knees digging thru that "shag-carpet" knows exactly where I'm comin from.......

Mine usually end up behind the refridgerator, but the best one was in my wife's potato salad! at least I got the spring back.