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View Full Version : gas port sizes on a 14.5" mid length, buffer tubes, and buffers/springs



n4p226r
7 July 2020, 17:27
why do manufacturers not really post gas port sizes? i feel like all the information about barrels is out there except for this info.
i was wondering if someone could help me with gas port sizes on 14.5" mid length barrels. Since there is no industry standard i was wondering what the range is that people think is not "overgassed". i have a 14.5" barrel, mid-length with a vltor a5 stock setup. i spent all the time and money researching everything about the stock and setup and how everyone likes it compared to a stock mil spec carbine buffer. even that you have H1 and H2 buffers to mess around with. Are these all bandaids for overgassed barrels?

i seem to find spec of a few here.
http://www.weaponevolution.com/forum/newthread.php?do=newthread&f=4

for 14.5 mid length the smallest port I've found is .075 by hodge defense and the largest .081 with noveske and a few others. both respected brands but both on opposite sides of the spectrum. my noveske i have in hand is .081 as well.

UWone77
7 July 2020, 18:51
I think part of the reason why they don't publish gas port sizes... they don't want people to start drilling. Over the last 5 years, I've never seen so many people attempting to alter their own gas ports with a drill.

Others probably don't publish gas ports because they over gas them on purpose. They don't want people calling to complain asking why their $300 barrel doesn't cycle Tula ammo. No matter how much you put a disclaimer up that the barrel is designed to run with HOT NATO ammo, people shoot the cheapest ammo possible.

It's also venture to guess that it's easier to sell barrels with opened up ports, so people can put adjustable blocks on them to tune them to their own needs and uses... like suppressed shooters.

Former11B
7 July 2020, 19:19
It’s weird they don’t since people can just pin gauge them and post it online afterwards. Like Rosco barrels will mock people for asking on IG. I personally like to know since i shoot suppressed a lot.

I reference this chart occasionally
https://docs.google.com/spreadsheets/d/1tXunBDX5Gaz87BqxwNxDUlWNK9nEv-cZEQoLq2JXXrk/htmlview

Former11B
7 July 2020, 19:22
Double tap

n4p226r
8 July 2020, 06:57
I think part of the reason why they don't publish gas port sizes... they don't want people to start drilling. Over the last 5 years, I've never seen so many people attempting to alter their own gas ports with a drill.

Others probably don't publish gas ports because they over gas them on purpose. They don't want people calling to complain asking why their $300 barrel doesn't cycle Tula ammo. No matter how much you put a disclaimer up that the barrel is designed to run with HOT NATO ammo, people shoot the cheapest ammo possible.

It's also venture to guess that it's easier to sell barrels with opened up ports, so people can put adjustable blocks on them to tune them to their own needs and uses... like suppressed shooters.

I totally understand that line of thinking. And to be honest I don't have enough rifle experience where I can really tell what overpassed even feels like.

Its crazy you say people try to drill their own gas ports and here I am wondering if I should be going smaller.

fledge
8 July 2020, 07:33
If you need to go smaller semi-permanently, get a reduced from Black River Tactical. Either an insert or gas tube.

BoilerUp
8 July 2020, 17:58
Hmmm...I'd personally be inclined to stick to carbine length gas system on a 14.5" barrel since that is what it was actually designed for. If you do that, there is a published spec for gas port (.0625, I think). I'm a fan of the SOCOM barrels.

UWone77
8 July 2020, 19:45
Hmmm...I'd personally be inclined to stick to carbine length gas system on a 14.5" barrel since that is what it was actually designed for. If you do that, there is a published spec for gas port (.0625, I think). I'm a fan of the SOCOM barrels.

I went with this philosophy with a couple of 14.5 barrels I cut down to 10.3" The guns only cycle suppressed, which is perfectly gassed for that purpose.

OP, what are you trying to accomplish exactly?

n4p226r
9 July 2020, 07:31
I went with this philosophy with a couple of 14.5 barrels I cut down to 10.3" The guns only cycle suppressed, which is perfectly gassed for that purpose.

OP, what are you trying to accomplish exactly?

just bringing it up for informational purposes. I just didn't understand why it wasn't a published spec. I get that they tend to go larger to cycle cheap ammo but I never use cheaper ammo than m193 from PMC or the green tip lake city bags of stuff.

it seems like the info can't really be proprietary (as anyone can test it after buying a barrel and publish the info). but if you were building a suppressed only gun, you'd want it a certain way. or if you hand loaded on the hotter side, you may want it a certain way.

for example, I recently got a noveske afghan barrel for an AR build. now it was a noveske gen 3 receiver and a noveske quad rail so it made sense to stick with a noveske barrel (in my mind). a lot of people complain noveske is overpassed at .081 on the 14.5" mid length. so I was wondering what size port isn't considered "overgassed". now im sure ill be fine as I can't shoot suppressed and I have another CHF noveske 14.5 with the same stock setup so its not a big deal for me. I'm sure ill be fine.

Former11B
9 July 2020, 09:10
I went with this philosophy with a couple of 14.5 barrels I cut down to 10.3" The guns only cycle suppressed, which is perfectly gassed for that purpose.

OP, what are you trying to accomplish exactly?

Same here

I pin gauged it just to verify the port size (FN CHF barrels).

I never shoot it unsuppressed so it’s fine. I could open it up but I don’t want the extra gas