Monday, June 28, 2010

$1.75 Solution to a 9mm AR-15 Problem

I was just about to order a Spike's 9mm buffer, but did a quick search first.  It would seem that someone on the message boards discovered that 7 quarters dropped into the buffer tube, before installing the recoil spring and buffer, make a perfect buffer spacer.

I have an RRA 9mm buffer, but it is standard 5.56mm length.  The 9mm bolts don't need to travel as far back as a .223Rem/5.56mm bolt carrier, and they're heavier.  What happens is the 9mm bolt gets a good running start at the bolt catch.  The bolt catches take a beating.  I had a Model 1 bolt catch in the lower I first ran the 9mm upper on, and the catch quickly got bent to the point that I had to replace it.

You can get longer 9mm buffers from Spike's, Hahn, or Slash, but they aren't cheap.  Spike's also makes a buffer spacer, for people like me who already have an acceptable short buffer, but it's still nearly $30 shipped, for a small piece of machined aluminum who's sole purpose is to take up a little space in the buffer tube.

Sure enough, the American 25¢ piece fit right in both Commercial and Mil-Spec carbine buffer tubes.  Although I haven't tried the quarter trick live-fire yet, it should work just like the Spike's 9mm Buffer spacer.  The quarters won't fit inside the coils of a buffer spring, so I have no reason to doubt those who swear it works very well, and there's really nothing to lose.

UPDATE, 9/12/2010: Tried it out. Seems to work well. Put 4 30-Round mags, and a 20-Round mag through my RRA 9mm upper, with Hahn mag block and RRA 9mm buffer, without any issues. I have, on a couple occasions, had stovepipe jams with this set-up without the quarters, but no problems today. I was running hollowpoints too.

It seems like I could get another quarter or maybe two more into the buffer tube, and still be able to lock the bolt to the rear.


Anonymous said...

Friend of mine maintains his AR by taking the buffer out, stretching the spring a bit and dropping a quarter into the tube every fall before we start chasing coyotes. Not sure if he now has several in there or not. But I've never seen his gun miss a beat.

Tank Dimbsey said...

So all i need is a CAR-15/M4 9MM FIXED STOCK BUFFER TUBE SPACER, and 7 quartes and my problem is fixed. I have a 9mm carbine rifle will it still work?

Suburban said...

All my carbines have carbine receiver extensions. I suppose that the same would work with fixed stocks also.

Skip the buffer spacer, that's what the quarters are replacing.