Undergassed DD 14.5 mid (URG-1 type)

[Wake27]

It doesn't surprise me entirely. My factory URGI wouldn't lock back every now and then with an A5-3 buffer and green spring on M3 PMAGs. I think everyone else is right that there is something else wrong for it to be that often, but I wouldn't be surprised if its something minor as I was thinking that mine was just a tad undergassed.

[prepare]

Sounds like a gas block related issue. Maybe not properly aligned with the gas port?

[mack7.62]

Forgot to mention that mags used were PMAG Gen 3's, already pulled gas block and confirmed alignment, I agree to me gp seemed a little small but should be working better. Next I will swap in a different BCG and see how it does.

[Biggy]

Here is some more info that may help. Also, check the end of your gas tube for wear and a good seal. I have seen more than a few bad from the factory. IMHO, if your barrels gas port checks .075”, it probably isn’t the barrel causing the issue.

https://www.m4carbine.net/showthread...s-Not-Sure-Why

[Iraqgunz]

The DD barrels I have seen in the commercial world were slightly larger. .076-.078 as I recall.

Those are off the shelf 14.5" mids. The barrel isn't your problem.

[Zane1844]

It doesn't surprise me entirely. My factory URGI wouldn't lock back every now and then with an A5-3 buffer and green spring on M3 PMAGs. I think everyone else is right that there is something else wrong for it to be that often, but I wouldn't be surprised if its something minor as I was thinking that mine was just a tad undergassed.

That was the 10.3?

[Wake27]

That was the 10.3?

Nope, 14.5.


Sent from my iPhone using Tapatalk

[17K]

The DD barrels I have seen in the commercial world were slightly larger. .076-.078 as I recall.

The barrel was spec'd to be a COTS purchase. The port is supposed to .076". If it's not, it's out of spec.

[Badger52]

Tagged just for interest.
In the "1 datapoint" category, my recent 14.5" mid-gas BA, Hanson profile with their lo-pro gas block & standard PSA BCG, H1 w/standard spring, runs XM193 like a turpentined cat - with Magpul G2 or 3's, D&H, or some old Okay's rescued from a dumpster in Logar Province - and at 23°F. Gas port is .076.

[pyrotechnic]

Have you checked the lower? I had a lower once where the bolt catch would not consistently engage the follower on Gen 3 Pmags (or other gen) but would do so with aluminum magazines.

Sent from my SM-G950U1 using Tapatalk