teedge77

I probably should have said "to meet the minimum dwell time." It sounds like we are on the same page though. Too short of a barrel and/or too small of a gas opening can be a problem.

Hmmm... to better qualify this, think of it this way instead "there is an optimum length of barrel beyond the gas port for minimum dwell time"

A 20 inch barrel is my sweet spot for accuracy/aesthetics. The mid-length gas system is aesthetically important to me as it will hide the gas block under the handguards. As far as dwell time, I think you may have it slightly reversed. In the case of a rifle-length gas system and a 16.5 inch barrel, you would then not have enough dwell time. Lengthening the barrel a couple inches will increase the dwell time and then you can pretty easily adjust the gas block/pressure back some (decreasing it) as/if needed. Even a 26 inch barrel and a mid-length gas system wouldn't suffer terribly from dwell-time issues. The length of time that gas is coming back through the gas tube will not outlast the cycling of the bolt. (You won't have gas coming out of the tube still when the bolt returns.) Please, if this is incorrect...someone set me straight. Thanks. Also, thanks for the welcome unforgiven.

Thanks for the help; I sent him a PM. I am going nuts looking for a barrel and I hope he (or someone else reading this) has some good news for me.

No, got an upper lower set from MidwestPX. Lower is finished and BCG is on backorder. Just need to get the barrel, gas block, and tube. Then it'll at least be shootable. (Although still needing a lot more, I'll feel good about it being "shootable".)

New(ish) to the forums, so hello to everyone. I've been reading a while and, to be frank, I was hoping I could finish my build using all the advice and examples in here without having to post a question. I really wanted to say "hey guys, look at this. I built it using all the info in here and there's so much I never even had to ask anything." Unfortunately, I think I am trying to move outside the norm a little. What I mean is, I am turning into a picky little bastard. What I really want is a 20-22 inch barrel that has a mid-length gas system. However, I can't seem to find a gas system on the 20+ barrels that isn't rifle-length. I have the MA-TEN rifle length monolithic upper and really want the gas block hidden under the rail. I have seen instances where people say the company making their barrel needs a length specified for the build. Does anyone have any ideas on where I can find what I am looking for, or can someone recommend a place that will cater to my somewhat odd needs (wants)? Thanks for any help anyone can give and glad you are all here for questions like this.