Broad River Tactical AR 15 SD radial delayed blowback barrel vs MP5 SD. B&T suppressor and 115g Blaser Brass. The audio on my cell phone sucks, the impact of the round and echos makes the audio sound like the rounds were going supersonic even from the SD, they were not. I need to try again when I can get out in the open and with a better mic. I also need more trigger time, but first impression is the MP5 SD still has the edge with smoothness and sound. Broad River Tactical parts were all top notch and, super nice fit and finish.
More testing to come.