Big Gas-Port 8"?

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JeffWard
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Big Gas-Port 8"?

Post by JeffWard » Thu Mar 02, 2017 5:13 pm

Looking for a 7.5-8" barrel with a big enough gas port (0.100-0.125") to reliably cycle subs.

Any good sources? Price is a factor. Obviously, this isn't a long-range barrel... It's a suppressible truck-gun.

Jeff Ward
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dellet
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Re: Big Gas-Port 8"?

Post by dellet » Thu Mar 02, 2017 5:27 pm

JeffWard wrote:Looking for a 7.5-8" barrel with a big enough gas port (0.100-0.125") to reliably cycle subs.

Any good sources? Price is a factor. Obviously, this isn't a long-range barrel... It's a suppressible truck-gun.

Jeff Ward
Unless you hand load, there is no reason to go that big unless you want to be severely over gassed with supers. Unless you are running very fast powders, which factory ammo won't use, even something around .090 will be reliable without a suppressor if the rest of the build is correct.
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Roverhound
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Re: Big Gas-Port 8"?

Post by Roverhound » Thu Mar 02, 2017 5:55 pm

My 9.5" Ballistic Advantage barrel has a .100 gas port.
I would imagine their 7-8" sizes would also.

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Re: Big Gas-Port 8"?

Post by bangbangping » Thu Mar 02, 2017 6:52 pm

Roverhound wrote:My 9.5" Ballistic Advantage barrel has a .100 gas port.
So does my 8" BA. And it's extremely overgassed with supers. Heck, it's overgassed with suppressed subs.

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Re: Big Gas-Port 8"?

Post by Roverhound » Thu Mar 02, 2017 7:26 pm

bangbangping wrote:
Roverhound wrote:My 9.5" Ballistic Advantage barrel has a .100 gas port.
So does my 8" BA. And it's extremely overgassed with supers. Heck, it's overgassed with suppressed subs.
That's why I put an adjustable gas block on mine.

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bangbangping
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Re: Big Gas-Port 8"?

Post by bangbangping » Thu Mar 02, 2017 9:46 pm

Roverhound wrote:
bangbangping wrote:
Roverhound wrote:My 9.5" Ballistic Advantage barrel has a .100 gas port.
So does my 8" BA. And it's extremely overgassed with supers. Heck, it's overgassed with suppressed subs.
That's why I put an adjustable gas block on mine.
So did I. Just trying to reinforce dellet's statement that a .100" port isn't needed.

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Re: Big Gas-Port 8"?

Post by JeffWard » Fri Mar 03, 2017 8:15 am

I seem to remember my current 300 (8.25") has a .094 port.

I guess I'd rather go with a bigger port, and adjustable gas, than a smaller port, and have to get it drilled.

Ballistics advantage makes good barrels, I have a Hanson Profile in my 308.

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Re: Big Gas-Port 8"?

Post by Dolomite_Supafly » Fri Mar 03, 2017 8:18 am

bangbangping wrote:So does my 8" BA. And it's extremely overgassed with supers. Heck, it's overgassed with suppressed subs.
5+ years ago all you heard on this board was "Drill the gas port at .125 and forget it. I have said a .125" port would be over gassed without an adjustable gas block but had a bunch of people tell me I was wrong. Had someone tell me my .93" port was an oversized "whisper" port and that it would not work but it did for thousands upon thousands of rounds.

If you do not want to run an adjustable gas block find a barrel with the smallest port you can then slowly drill it out until you get it to function with the ammunition you are using. I normally go up by .003" at a time until it locks back then I go another .003" for reliability.
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Re: Big Gas-Port 8"?

Post by tfbit » Mon Mar 06, 2017 12:27 pm

This is general advice for 16" carbine gas barrels and I'd still give it. Anytime I see someone say that about a shorter barrel I usually will dispute it.
Dolomite_Supafly wrote:5+ years ago all you heard on this board was "Drill the gas port at .125 and forget it."
No matter what you read on the intarweb CCI450s and CCI41s ARE NOT BALLISTICALLY IDENTICAL with H110! I'm also not a intarweb lawyer so I don't argue with anyone who is.

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Re: Big Gas-Port 8"?

Post by Blowout » Tue Mar 07, 2017 3:05 am

I have a 8.5" KAK and it has a .125 gas port. Use an adjustable GB to turn the gas down when needed.
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