here you go:
http://www.srtarms.com/ebr.htm
Not cheap but available
7.62 x 39 Subsonic
General Description: 7.62 x 39mm M4 Jackhammer. This new EBR round is designed
to feed and function M16/M4 weapons in this caliber in both semi and full auto. It
utilizes a proprietary EBR 220 grain FMJ projectile. Also works in Kalashnikov weapons
with slight ramping. Cycles both weapons with or without a suppressor. Independent
testing has given sub-1/2 MOA accuracy at 100 yards using aimed, semi automatic fire.
Light recoil and enhanced controllability make this ammunition extremely effective in
full automatic mode.
7.62 x 39mm (500 Rounds, 10 Boxes of 50 per case)
1 box, $66.50
2-5 boxes, $61.75
6-9 boxes, $55.00
10 boxes or case, $450.00 or $475.00 per box
10 cases +, $427.50 Per Case (5% discount)