I just fired my Arsenal SA M5 today for the first time. Lots of fun dancing cans over the top of the berm. It worked great with circle 10 waffle mags, promag not so much. Ammo was wolf gold 55 fmj. Hard to fit longer bullets into an AK mag, no big deal in my book. I love the rifle. My range has a silly rule against 30 rifles in their tactical bays. Some idjit shot over the top and killed a cow with a 308. (Of course cows are immune to 22 bullets, right? Shhhh!) I much prefer the ammo availability of 223/5.56 over 5.45.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=544086200
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=544086200