I’m in the process of assembling two SBR uppers/complete guns that will be dedicated suppressor hosts. I believe I’ve largely figured out the component and set up details but wanted to float them here. I’m looking for a sanity check to ensure my thinking is sound and for answers to a couple of outstanding questions.

Some details. Both uppers will be assembled with high quality parts (mil-spec uppers, BCM BCGs, URX rails, and probably BCM barrels, etc). FWIW, the lowers have DD LPKs, mil-spec RE, standard springs, and H buffers (for now). Both barrels will be 11.5” long and wear muzzle brakes. One upper will host a SF SOCOM RC (still pending) and the other will host a Gemtech G5 (had for a few years).

My plan is to run these uppers/guns suppressed 90-100% of the time. If/when unsuppressed, they’ll get fed quality M193 ammo. I may use some weaker stuff (i.e. PMC Bronze) with the cans on. I’m a civilian so these are not work guns. They will get used for carbine classes/training and one of them may eventually turn into an HD gun.

Bottom line, I would prefer that these function unsuppressed (I’d drop down to a carbine buffer if needed) but it is more important that they run without issue and without unnecessary wear (not overgassed) when suppressed.

I’ve read a number of M4C threads about gas port sizing and adjustable gas blocks, including the one about Grant’s dedicated suppressed gun. I’ve come to the preliminary conclusion that I’d prefer a small gas port barrel vs. the other options. I’m currently thinking about grabbing a couple of carbine gassed 16” BCM barrels and having them cut to 11.5”. Assuming the barrels are in spec, that should leave me with gas ports that are approx 0.063”.

So my questions are:

1. Is cutting 16” carbine barrels down to 11.5” the most efficient way to get the right gas port size for this application, and is 0.063” about the right size?

2. Does anyone with a set up like this regret not getting an adjustable gas block instead?

3. My limited understanding of suppressors and back pressure suggests that the SOCOM cans generate less back pressure than most (the Gemtech G5 in my case) cans. Should this be a consideration for me (i.e. should the SOCOM host get a relatively smaller gas port)?

Thank you.