Reports of DD SBR barrels being over-gassed?

[Iraqgunz]

I don't know where you are getting your port size numbers from, but there is no standard for a 12.5". Simply because there is no TDP.

The same goes for 11.5" and 16" and 14.5" middies.

My particular BCM upper is not much smaller than yours.

Colt 6933's are around the same IIRC. If you want to change the feel, run a -4 buffer, Springco spring (green) and get an LMT enhanced carrier.

1. Of course, and expected. But this seemed like definitely too much. Red dot was up and off paper every shot. All the other guns I tried including a 12.5" midlength (i know...) suppressed switchblock A5H2 with an acog was much more stable.
2. I compared 16s, 14.5s, an 11.5, another 12.5"
3. ...... I was a asshole shooting PMC Bronze
4. I will. I need to strip it down and get some pin gauges in there. I don't own a set but I'll try and do it tomorrow at lunch. I've read that .068-.073 would be pretty reasonable for a 12.5 carbine. My guess is high .070s into low .080s

[Noodles]

well its obviously not too over gassed as it is not malfunctioning.

Exactly my concern. I did shoot this gun with the Socom 556, and A5H2, and while it was noticeably less gas in the eyes than the AAC m42k on the same gun, it was there within 10-15 shots.

I stepped up to an A5H3 on this gun but have not had a chance to run it with that can again. I will next week.

[Noodles]

I don't know where you are getting your port size numbers from, but there is no standard for a 12.5". Simply because there is no TDP.

Yea... I'm well aware there is no TDP for a 12.5. Never said anything about that. I said I've read of people measuring 12.5s and getting common results of .068-.073. That's counting some Noveske, BCM, LMT, etc.

I'm going to pull mine and gauge it tomorrow. If it's really that large, it's gone, there is just no excuse for that much extra gas from one mfg to another. I paid for a DD barrel so I wouldn't end up with an overgassed Bushmaster. I'll call DD tomorrow as well.

[nml]

Your gun is extremely light weight with no compensator. Plug your gas port, it's still not going to shoot like his.

The obvious solution is to buy a larger caliber to shoot alongside your 223

[snackgunner]

Holy ****. If that's the case, I'm probably moving over to a BCM LW. I know those are a LOT smaller. .081 is 10.x territory.

Damn man you're making me want to trash my DD rifle. Does a .081 gas port size on a 12.5" really suck in terms of recoil?

Your thread title says "reports" of DD barrels being over-gassed. Where are you getting these reports from?

But yes that's what DD said when I called them. I'm not 100% sure if it was a rep that I talked to, because when I asked the question, the lady had to go and ask someone else for the answer because she was not sure.

Give them a call tomorrow and report back.

[Iraqgunz]

Well I disagree because I am pretty sure that BCM ports are not that small. I am 99.9% that mine is .078 and that their 11.5" is .076.

That's pretty much across the board.

If you think Bushmaster is that small you would be wrong. They gas their 16" carbines at .080 and their SBR's are larger. Like in the .090 range +.

Yea... I'm well aware there is no TDP for a 12.5. Never said anything about that. I said I've read of people measuring 12.5s and getting common results of .068-.073. That's counting some Noveske, BCM, LMT, etc.

I'm going to pull mine and gauge it tomorrow. If it's really that large, it's gone, there is just no excuse for that much extra gas from one mfg to another. I paid for a DD barrel so I wouldn't end up with an overgassed Bushmaster. I'll call DD tomorrow as well.

[Noodles]

Your gun is extremely light weight with no compensator. Plug your gas port, it's still not going to shoot like his.

The obvious solution is to buy a larger caliber to shoot alongside your 223

Yea, It's already shooting like a 300blk, so I might as well step up

I'm putting a brake on in short order. I'm civ, I don't need a flash hider vs being able to put more hits on target faster. I also decided I don't care about the shooter next to me, **** you, get better muffs!

Seriously though, I get that under 7lbs, and no brake it's not going to shoot like a gamer gun, but even the carbon barreled 12.5 with acog was about the same weight, A5 buffer, and switchblock which is where I think the difference was. There were light guns there and they allowed the guys to keep the dot on paper easier.

I did ****ing fantastic with 10y and 50y accuracy when it was slow fire. I know I give it up a little when it's rapid because I suck, but this gun isn't helping me get better with that.

[Noodles]

Well I disagree because I am pretty sure that BCM ports are not that small. I am 99.9% that mine is .078 and that their 11.5" is .076.

That's pretty much across the board.

If you think Bushmaster is that small you would be wrong. They gas their 16" carbines at .080 and their SBR's are larger. Like in the .090 range +.

I'll pull go back and find some of posts that had gas port sizes tomorrow when I get this measured. I pulled it apart and got calipers on it, but no batteries in them and I think a pin gauge set will be better.

[jaxman7]

Well I disagree because I am pretty sure that BCM ports are not that small. I am 99.9% that mine is .078 and that their 11.5" is .076.

That's pretty much across the board.

If you think Bushmaster is that small you would be wrong. They gas their 16" carbines at .080 and their SBR's are larger. Like in the .090 range +.

That is just, well sad. Nothing more aggravating to me than a way over gassed/snappy AR. Useless, poorly designed components made to be compensated for by a lack of quality through a bigger gas port.

-Jax

[Noodles]

Damn man you're making me want to trash my DD rifle. Does a .081 gas port size on a 12.5" really suck in terms of recoil?

Don't listen to a thing that I write. If your gun shoots well for you don't do a single thing.

I'll call DD and get a measurement tomorrow. I'll also have a friend strip down an 11.5" BCM and see.

There is just no logical reason that my 12.5" would have such noticable recoil compared to every other gun there with an A5H2 or A5H3 buffer except for gas, weight, and muzzle device but I pretty much process of elimination removed two of those.

It is probably just a mix of all three things. I'll almost certainly get a micromoa or other block, add a SF fury or scout, and put a brake on. That should probably fix it up, but I'm almost certain it's over gassed currently.