$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 AR15.com 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.