Last Saturday, I was at my Class III friends house shooting my AR with my hopefully, soon possess, suppressor.
Anyhow, my friend was standing to my right side listening to my suppressor with different ammo being used and he said, "take your can off and shoot your AR un-suppressed." Which I did.
Then he said, "Okay, put your suppressor back on and shoot." Again I did as he said.
Well once I did that, he explained to me that my AR wasn't cycling properly.
1) My brass was only ejecting 4-6 feet from me, and
2) My rifle bolt looked and sounded sluggish.
He then asked me to load up my magazine with 5-rounds and shoot as fast as I could. I did and by the third round I had a jam. He then asked me to load up 2-rounds and fire as fast as I could. Both rounds got slung down the range BUT the bolt carrier did not remain open when the mag was empty.
He asked me to pull out the bolt and we cleaned it and reoiled it. Then did the 5-round, 2-round redux and again my rifle had similar results as written above.
Well off to his shop we went.
When in his shop he took out my buffer and spring and weighed my original Colt buffer and it was 3.8 OZ. He took a buffer from one of his SBR and weighed it and it was 3.0 OZ. So he swapped out the 3.8-OZ for the 3-OZ and off to the range again.
I ran the above exercises all over again and VIOLA! I had no other issues. My bolt wasn't sluggish, I had no jams, and when the mag was empty my bolt remained open.
He scratched his head and said, "usually when you run a suppressor you have to add a heavier buffer but not with your Dead Air". I asked him if that was good or bad and he replied "neither. It is what your rifle likes."
My friend went on to comment that he thought that the Dead Air can was doing a great job dispersing the gasses so there was minimal "blow back" unlike many other suppressors he has used during his tenure in this business.
Interesting...
