6.5 creedmoor AR-10 issue

rgitzlaff · January 21, 2023, 09:45 PM

I have an aero precision 6.5 creedmoor with a 22” barrel. It has a rifle length +2” gas system as well. I’ve been using it for a few years with an adjustable gas block but have been meaning to get a superlative gas block because I like the idea of having it run cleaner. Finally installed the superlative with the .025 gap according to the instructions, and turned out 18 clicks to make it wide open. When testing the brass ejection direction as not consistent and it kept stove piping. I would say it doesn’t have enough gas but I can’t open it up anymore. No issues as all with the old restrictive style adjustable gas block. I’m tempted to put the old one back on, but not ready to throw in the towel just yet. Anyone have any ideas?

reynolds357 · January 21, 2023, 10:10 PM

As stupid as it sounds, try closing off the gas block some. I have seen it work, but have no clue why it does.

MarkCO · January 21, 2023, 10:54 PM

Depending on what load you are using and buffer, you might not need adjustable gas. My Stag Large frame in 6.5CM does not need adjustable gas with the loads I am running. Mine is 20" with rifle gas. Load is 143s. 2600 fps and faster run 100%. 2550, not enough gas.

stagpanther · January 22, 2023, 12:35 AM

I have several 6.5 and 6 mm creedmoor AR builds with the same barrel configuration and they all use SA blocks. Creedmoor seems to be one of those cartridges that you really need an adjustable block for if you go up and down in charges on an AR with handloads. You might have a dwell time or chamber roughness issue; case "stickiness" might be what is causing the stove piping--the carrier simply doesn't have the 'umph" to clear the spent case before cycling the next cartridge--or you might have an extractor issue that either doesn't get a good hold on the case rim--or maybe is too tight on it. Another possible issue is the bolt lock-up to extension--look for signs of uneven wear on the lugs. Creedmoor and grendel barrels are the two instances in AR's where I think it pays to get a matched bolt to the barrel when ordering the barrel.

I have to follow SA's directions precisely in order to get good operation, and sometimes that means readjusting for ladder tests that range from min to max. i might choose to single-feed the cartridges to get all the way through without re-adjusting the block, the idea being that I settle on a particular power cartridge.

Lastly, the block may not be properly clocked to the port on the barrel, if it is properly clocked there usually is a concentric carbon ring around the port.

DI gas running "cleaner?" sounds like a reach to market the block for that because either the gas cycles or it doesn't. If your old block functioned with no issues, I'd put it back on. Cleaning is cleaning, no AR can escape that.

Just a few ideas...

jetinteriorguy · January 22, 2023, 09:12 AM

Whenever I start having issues in any DI type rifle, first thing I do is oil it. If that doesn’t fix it I clean and oil it. This usually fixes at least 90% of the problems I’ve encountered over the years. If this doesn’t take care of the problem I’d put the old one back on and call it a day.

MarkCO · January 22, 2023, 09:59 AM

Quote:

Originally Posted by jetinteriorguy

Whenever I start having issues in any DI type rifle, first thing I do is oil it. If that doesn’t fix it I clean and oil it. This usually fixes at least 90% of the problems I’ve encountered over the years. If this doesn’t take care of the problem I’d put the old one back on and call it a day.

Add magazines to the things that "fix" a poorly running AR and you might be over 90%.

stagpanther · January 22, 2023, 10:16 AM

Quote:

Add magazines to the things that "fix" a poorly running AR and you might be over 90%.

Good point--forgot about that, especially in creedmoors with the bullets seated long they can have a tough time making it from the mag to chamber without the bullet nose hanging on something.

IIRC, (I'm overseas at the moment ands don't have access to directions) the SA block is sort of a "2 stage" gas block--at first you are adjusting amount of gas coming through the port through the block--and then "fine tuning" with gas bleed-off.

jetinteriorguy · January 23, 2023, 06:01 AM

Quote:

Originally Posted by MarkCO

Add magazines to the things that "fix" a poorly running AR and you might be over 90%.

Ah, good catch.

January 21, 2023, 09:45 PM	#1
rgitzlaff Senior Member Join Date: January 8, 2006 Location: Madison, WI Posts: 522	6.5 creedmoor AR-10 issue I have an aero precision 6.5 creedmoor with a 22” barrel. It has a rifle length +2” gas system as well. I’ve been using it for a few years with an adjustable gas block but have been meaning to get a superlative gas block because I like the idea of having it run cleaner. Finally installed the superlative with the .025 gap according to the instructions, and turned out 18 clicks to make it wide open. When testing the brass ejection direction as not consistent and it kept stove piping. I would say it doesn’t have enough gas but I can’t open it up anymore. No issues as all with the old restrictive style adjustable gas block. I’m tempted to put the old one back on, but not ready to throw in the towel just yet. Anyone have any ideas?

January 21, 2023, 10:54 PM	#3
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 3,849	Depending on what load you are using and buffer, you might not need adjustable gas. My Stag Large frame in 6.5CM does not need adjustable gas with the loads I am running. Mine is 20" with rifle gas. Load is 143s. 2600 fps and faster run 100%. 2550, not enough gas. __________________ Good Shooting, MarkCO www.CarbonArms.us

January 22, 2023, 12:35 AM	#4
stagpanther Senior Member Join Date: March 2, 2014 Posts: 10,723	I have several 6.5 and 6 mm creedmoor AR builds with the same barrel configuration and they all use SA blocks. Creedmoor seems to be one of those cartridges that you really need an adjustable block for if you go up and down in charges on an AR with handloads. You might have a dwell time or chamber roughness issue; case "stickiness" might be what is causing the stove piping--the carrier simply doesn't have the 'umph" to clear the spent case before cycling the next cartridge--or you might have an extractor issue that either doesn't get a good hold on the case rim--or maybe is too tight on it. Another possible issue is the bolt lock-up to extension--look for signs of uneven wear on the lugs. Creedmoor and grendel barrels are the two instances in AR's where I think it pays to get a matched bolt to the barrel when ordering the barrel. I have to follow SA's directions precisely in order to get good operation, and sometimes that means readjusting for ladder tests that range from min to max. i might choose to single-feed the cartridges to get all the way through without re-adjusting the block, the idea being that I settle on a particular power cartridge. Lastly, the block may not be properly clocked to the port on the barrel, if it is properly clocked there usually is a concentric carbon ring around the port. DI gas running "cleaner?" sounds like a reach to market the block for that because either the gas cycles or it doesn't. If your old block functioned with no issues, I'd put it back on. Cleaning is cleaning, no AR can escape that. Just a few ideas... __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!* Last edited by stagpanther; January 22, 2023 at 12:46 AM.

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January 21, 2023, 10:10 PM	#2
reynolds357 Senior Member Join Date: December 10, 2012 Posts: 6,124	As stupid as it sounds, try closing off the gas block some. I have seen it work, but have no clue why it does.

January 22, 2023, 09:12 AM	#5
jetinteriorguy Senior Member Join Date: April 28, 2013 Posts: 2,771	Whenever I start having issues in any DI type rifle, first thing I do is oil it. If that doesn’t fix it I clean and oil it. This usually fixes at least 90% of the problems I’ve encountered over the years. If this doesn’t take care of the problem I’d put the old one back on and call it a day.