Cycling issues going from 20" to a 22" barrel

[Frankie12f]

New to the forum and thank you for the add. I bought a pre-assembled 6.5 creedmoor upper from Delta Team Tactical with a ss 20" barrel and it ran amazing never had a problem with any factory ammo had shot plenty of roundsthrough it. But I purchased a 22" fluted BA stainless barrel. Installed it and aligned gasblock properly (nonagb) rifle length tube and its the right length. But it's having a hard time cycling. The nosler wouldn't even pick up the next round it would discharge the spent case fine but seem to short stroke and my bergers would get caught half way in the cycle. Sometimes it cycles a couple rounds fine and sometimes it don't for the bergers that is. But the nosler i could never do a following up shot it would re-engage the hammer but no bullet in the chamber so would have to manually cycle it. All I did was change barrel, gas tube and block. But I have some weird marks on the backside of my bolt lugs almost like the bolt is trying to go into it's cycle before the lugs are fully disengage from chamber. Any help would be greatly appreciated thank you.

[Frankie12f]

Wish I knew how post pictures on this forum lol

[gman47564]

Welcome to the forum frankie.. dont know alot about the ar10's even though i shoot one.. but theirs some guys on here that do know about them.. one thing i would check if you still have your old barrel and thats the size of the gas port hole in the barrel.. and also make sure the hole is lined up correctly.. i have seen guys use a short piece of spaghetti to do this.. break a short piece of spaghetti off the length of the hole in the gas block.. slide the gas block on the barrel and when the holes line up the spaghetti will fall into the barrel.. then just clear the barrel..

[Frankie12f]

I did check my alignment and it is dam near right on i don't think I could get it any better. I have read some people have solved this with a little heavier buffer but before ordering one didn't know if people have really had success with it. I will have to check my port opening on the old barrel to see if port size is the same or bigger smaller

[Windsage]

You said it was short stroking.  Have you tried just putting one round in the mag.  If you do this, does it reliably eject and lock open?  If so, then it's not short stroking.  If it does not reliably lock open, then you do not have enough gas, and since this is a 2" longer barrel, you should recheck the gas port size and alignment.

If it reliably locks open, then you could just be way over gassed and having feed problems.  Look at the direction the brass goes when it ejects.  You want the brass to eject at 3:00 to 4:00.  If it is flying off between 12:00 and 3:00 then you could be over gassed.  A heavier buffer uses more gas and could help if you are over gassed.

[Frankie12f]

Well I took my old barrel to compare with the new one and the gas port on the 22" is definitely smaller compared to the 20" a 5/64 drill bit is sloppy in the 20 and won't even go in on the 22.

[Frankie12f]

If you were in my position would you a go lighter on buffer and possibly bcg or drill barrel?

[gman47564]

Frankie i hesitate to say this because i have never done it.. but after you posted saying the hole in the new barrel was smaller i did some looking on you tube and found a few videos on the issues you've described.. in the videos i watched the guys just drilled the hole out bigger with a regular old hand held drill.. so im not telling you to do that but if it were mine i would get a drill bit the same size as the hole in your old barrel and drill the new one out to the same size.. but if your not comfortable doing that take it to a gun smith and have them drill it out.. if you do some looking on you tube you can find videos on this..

[autoxforfun]

You said it was short stroking.  Have you tried just putting one round in the mag.  If you do this, does it reliably eject and lock open?  If so, then it's not short stroking.  If it does not reliably lock open, then you do not have enough gas, and since this is a 2" longer barrel, you should recheck the gas port size and alignment.

If it reliably locks open, then you could just be way over gassed and having feed problems.  Look at the direction the brass goes when it ejects.  You want the brass to eject at 3:00 to 4:00.  If it is flying off between 12:00 and 3:00 then you could be over gassed.  A heavier buffer uses more gas and could help if you are over gassed.

I think Windsage gave a very good way to approach diagnosing the problem.  If you can not get the bolt to lock open, then opening the hole may be required....but I would first verify that this is the problem.

[Kansaswoodguy]

The difference in an AR-15 rifle length has tube and a AR-10 rifle length gas tube used by some barrel manufacturers is a 1/4" longer the AR-15 tube just barely makes it into the gas key and will short stroke the gun. Measure the distance on you old barrel and new barrel to verify they are the same. If they are then get a lighter buffer.AR-10 in 6.5 Creedmoor are normally over gassed so I suspect your gas tube is 1/4" short. Best to order gas tube from the same place you got the barrel from on AR-10's

[Frankie12f]

I ended up drilling the gas port on the barrel. The gas tube was right length. So far it's cycling my nosler rounds just fine that it wouldn't even pick up out of the clip before and in a 3-4 o'clock ejection pattern. Have to do more shooting with it but so far so good.

[Windsage]

I am glad this worked out for you.  Issues like this are why I never use a normal gas block.  I always use an adjustable gas block.  My favorite one in the Superlative Arms one.  I use them in restrictive mode, but I like that you can adjust them easily in the field.