Anybody dealt with Rosco Manufacturing barrels? I'm also looking at putting together a 11.5" upper for when my SRD556-QD gets approved. I emailed them and asked for gas port sizes, specifically for their 10.5" and 11.5" barrels. Below is the response I got from their Director of Sales & Marketing:
"<font face="Calibri">I hope that this e-mail finds you doing well and thank you for reaching out to us. The port size for our Bloodline barrels have been sized according to the caliber and length of each barrel. The goal is to take dwell times, reliability, and a long service life into account. We have also taken the extra effort to make sure that our barrels perform well under punishing conditions both suppressed and un-suppressed. </font>"
That doesn't answer my question, bud.