gas port size

Exactly
Find out what size it is drilled when they sent it to you first

victor3ranger said:

Exactly
Find out what size it is drilled when they sent it to you first

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I guess I should find out before I buy! AP barrels on 6.5creed have standard rifle length gas system unlike the +2's and some standard lengths that have cycling issues and pop primers with factory ammo. The AP's function 100% without an adjustable gas block and/or heavier buffer.

When I moved my gas block out of the way the hole in the barrel was something like .048, way way too small.
I wish I could remember exactly what size I ended up with but it was around .088-.089, I probably should have stepped up even more but it was cycling correctly and ejecting at about the 3:30 area so I stopped.
I have sent a bunch of rounds out of it now and it's functioning great plus very accurate out to 500-600

victor3ranger said:

When I moved my gas block out of the way the hole in the barrel was something like .048, way way too small.
I wish I could remember exactly what size I ended up with but it was around .088-.089, I probably should have stepped up even more but it was cycling correctly and ejecting at about the 3:30 area so I stopped.
I have sent a bunch of rounds out of it now and it's functioning great plus very accurate out to 500-600

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For reliability I always start them spitting to the 2:50-3:00. I see them drift to the 3:30 after some rounds put though it.

Gingerman said:

For reliability I always start them spitting to the 2:50-3:00. I see them drift to the 3:30 after some rounds put though it.

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Yep
After having that problem with mine I paid attention to my friends that were having trouble. They would change buffer springs, buffer, gas tubes and/or adjustable gas blocks trying to fix the problems.
I told them what fixed mine and they got to checking theirs.

victor3ranger said:

Yep
After having that problem with mine I paid attention to my friends that were having trouble. They would change buffer springs, buffer, gas tubes and/or adjustable gas blocks trying to fix the problems.
I told them what fixed mine and they got to checking theirs.

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I found the only thing that will control the brass pattern is the gas port size, whether drilled, or regulated by adj gas block. Changing springs, buffers, etc might take the ejector swipe off brass, that's about it.

Gingerman said:

I found the only thing that will control the brass pattern is the gas port size, whether drilled, or regulated by adj gas block. Changing springs, buffers, etc might take the ejector swipe off brass, that's about it.

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Yep

Let the Hilarity begin! So I finally figured out the Proof AR barrels have under sized gas ports from the factory. Many complaints. Logical and easy enough to solve. Trying to get my Gibbz side loaders to run right. They are clearly gas hogs. Have 4 Proofs - all the same. 3 in a row on the drill press - a thing of beauty. On #4, however, kerf grabbed the bit on the last bite and snapped the bit off.

No big panic - except I now need either a machinist with an EDM rig - or a different/better answer. Can't find an EDM shop in Cheyenne or Ft. Collins. Laugh away - but I'll take any advice or direction from this highly esteemed brain trust that I so enjoy reading. Flog away…….I can take it.

Might try asking in your local real auto parts store if there's a guy in the area who EDM removes broken bolts on equipment, earth moving or otherwise.

ntsqd said:

Might try asking in your local real auto parts store if there's a guy in the area who EDM removes broken bolts on equipment, earth moving or otherwise.

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Good idea - I appreciate it!

i need too check all my ar's that don't function with standard weight buffers, springs and carriers. if they run as they should with only non-adjustable gas blocks, then port size is perfect. the only 6.5creed barrels i have that will do that are from aero precision and use standard rifle (22") length gas (non-plus gas systems). 1 uses mid-length (18") and that 1 runs perfect using standard components and non-adjustable gb's.

18" .0635 port
22" .0730 port

a cbi barrel i have is very accurate w/hornady 123sst and a-max that uses rifle length gas, but has an op issue. i don't care to add weight to the buffer to try and fix the issue (that's if it'll fix it).

Here is a good link to gas port diameters on a variety of calibers and barrel lengths (also how to calculate the right gas port dia.):

UncleDano said:

Here is a good link to gas port diameters on a variety of calibers and barrel lengths (also how to calculate the right gas port dia.):

Barrel Gas Port Size,308/338/260/243 etc.

I'm starting a thread on this in hopes the STAFF here will make it Pinned . Only info needed here is if you know your Barrels Port size , post it here , with Manufacturer , Gas system length & Barrel length & if you had to make any changes to it to make it work if you had issues. Kreiger ...

forum.308ar.com

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to bad they don't list which and what recoil parts are being used along with non or adjustable blocks. it does make a difference

ARlife4me said:

to bad they don't list which and what recoil parts are being used along with non or adjustable blocks. it does make a difference

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I've never needed that. I always run a low mass bcg, lighter recoil spring and good click adjustable gas block and adjust it just open enough that the bcg stays back on an empty mag, then they run nice with almost no recoil. I've never seen the need to mess with all of the buffers and such that people like to mess with.