There are already a lot of BCM vs. DD threads, but I would like to ask a more pointed question:
Can anybody compare the gas port sizes of the 14.5 middy BCM and 14.5 middy DD uppers? I hear constantly about how smooth the BCM shoots, but not much about the DD. I assume this is partially a function of BCM’s small gas port size; I would like to know how the DD compare. In theory, assuming they have the same size gas ports, they should both run equally smooth when setup with the same length gas systems, buffers, muzzle attachments, etc. Thanks for the help.
Is there a trade off between “soft shooter” and reliability? The reason i ask is because i would think that if you had two of the exact same middies with 1 having a smaller port that even though it would be slightly softer shooting in an already soft 5.56 it would also be more prone to short stroking when its dirty or weak ammo etc… Again, this is a question not fact lol
I have also been wondering the same question as you and haven’t had any luck…in the meantime it got me thinking of the question above…I would be glad to measure for you but i have a DD carbine barrel. Hopefully sum1 will have the specs…
Your not going to get any info on this as very few people are going to have both barrels, and even fewer are going to have the ability to measure the GP’s.
I ran across something the other day but I cannot remember where… It said the DD gas ports are .075 inches. I can’t cite the source so it may be incorrect.
I’ve got a DD 14.5" Mid-length Lightweight and the gas port is .625" on that one. I’ve also got a ruined (bulged) BCM 14.5" Mid-length barrel hanging on the wall of a friend’s gun room that I can measure, but it will be sometime later this month before I can get to it. I wrote down all the specs on that BCM barrel when I did the build but it’s on a yellow legal pad somewhere. I need to find it and put all those specs in my database anyway so I’ll see if I can find it tomorrow.
It wasn’t fat fingering. That is bbl diameter/gas block diameter. That is for their light weight barrel. If you look at standard barrels it is larger. They don’t have the spec sheet labeled clearly.
They have the spec sheet labeled clearly, but I didn’t post the whole thing, only the Materials & Construction portion that shows the Gas Port Diameter. If you go to their site and look at it you’ll see that I only posted the lower portion of the spec sheet for the 14.5 Mid-length Lightweight barrel.
Clear and accurate are two different things. I said that they labeled their spec sheet clearly. They did. I posted that portion of their spec sheet to show gotm4 where I got my incorrect data.
Are you really going to sit here and argue semantics? Their sheet is unclear that they say the gas port diameter is .625" when clearly they meant gas block diameter/barrel diameter.
