In this real steel review by The Firearm Blog, they feature he Daniel Defense DDM4ISR which comes with a built-in suppressor... "In this episode of TFBTV, James Reeves performs a full review of the Daniel Defense DDM4ISR, or Daniel Defense Integrally Suppressed Rifle. James reviews this .300 Blackout AR-15/M4-type rifle with a built-in, permanently attached suppressor on the range in semi-auto format, and with a full-auto lower to see how it performs, and compares it to a suppressed bolt action rifle as well. How does the M4 ISR stack up? Watch today’s video to find out."