No, not my muscles...  We had weapons qualification earlier this week and brought along some other weapons to familiarize with (courtesy of EOD).  I got a few pictures and a couple of nice movies of the experience.  All the pictures are in the August gallery.  Here's one of my favorites:

More pics in the gallery, including some with a Dragunov russian sniper rifle (that was having some issues with actually firing).

The M82 is a beast of a gun.  It fires the same rounds as the .50 cal machine guns that we use.  It's heavy and extremely loud.  You'll see what I mean in the movie below - it literally causes a shockwave that shakes the ground enough to raise a big cloud of dust for like a 4 or 5 foot radius around the gun.  I've used the rifle a lot in computer games like Ghost Recon, so I was eager to see how it handled in real life.  It's got quite a bit of kick, and of course the games don't do the noise or shock of firing it any justice whatsoever.  I'm sure firing it from anything but prone and braced position would knock me on my butt.

This movie is another soldier firing a couple of rounds from the Barrett.

This movie is me firing an AK -- my buddy only got me firing semi-auto, not full auto, but oh well.