BCM/DD 14.5 Gas Port Sizing

[D. Christopher]

DDs gas ports for CAR gas guns (14.5-16") is .0625"

You're right and they're wrong.

[justin_247]

You're right and they're wrong.

Somebody definitely fat fingered this. It's .0625"... period.

gotm4 is 100% correct.

[tylerw02]

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.

[D. Christopher]

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.

[tylerw02]

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.

They are not clear in that the gas port diameter is NOT 0.625".

Look at the 14.5 Mid-length Government profile:

Materials & Construction

* Barrel Material: Chrome Moly Vanadium Steel
* Barrel Type: Cold Hammer Forged
* Barrel Caliber: 5.56 NATO
* Barrel Twist: 1:7
* Barrel Length: 14.5″
* Barrel Profile: Govt Profile
* Barrel Gas System: Mid-Length
* Inside Finish: Chrome Lined
* Outside Finish: Military Specification Heavy Phosphate Coated
* Muzzle Thread: 1⁄2×28 TPI (Threads Per Inch)
* Gas Port Diameter: .750″
* Barrel Extension: A4
* Made in the USA!


So if what you're saying is true, they are use a 3/4" gas port on government weight barrels? They mislabeled the spec.

[eternal24k]

I spoke with DD last week regarding those numbers, they are the diameter for the gas block, period.
Regarding the 16" port I was told that if their

memory serves [them] correctly, the gas port diameter on a 16” Middy barrel is around .070”.

so I can't imagine that it would be smaller for a 14.5"

[D. Christopher]

They are not clear in that the gas port diameter is NOT 0.625".

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.

[tylerw02]

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.

[Dirtyboy333]

it means barrel diameter at the gas port. its a little unclear

[ryu_sekai]

Any updates, I would still like to know