Bolt Carrier not staying back question

[Thanos]

Okay, so I have this hot rifle and took it out to a range that only allows one round in at a time. Not a big deal I like the range and it is close to my house in a major metropolitan city. I am using Wolf ammo, I know it is not great but I have 800+ rounds left. Now to my question:

Every few rounds the bolt carrier does not lock back but cycles as though there was another round in the magazine. I think this may be a problem with not enough gas force to blow it back all the way and I should (Since I have an adjustable gas block) adjust it out to allow more gas through the tube, i.e. more pressure to throw the carrier back.

What do you think? I have not taken it to the range since but I am planning on going in a week or so.

[fightingquaker13]

I'd talk to the range, explain that you're trying to diagnos this problem and see if they'll cut you some slack.
fightingquaker13

[alfsauve]

.... a range that only allows one round in at a time.

Not clear on what the problem is.  They only allow you to one round in the magazine?  Failure to lock back is against range rules?  What if there is no hold open device?  The most restrictive range I've ever been on only allow a max firing rate of 1 shot per second.

I should (Since I have an adjustable gas block) adjust it out to allow more gas through the tube, i.e. more pressure to throw the carrier back.

Yes, but first do an inspection to make sure there isn't some obstruction or other reason for the carrier not properly functioning.

[twyacht]

Try a few rounds of "better" ammo.  My 556 would do the same only with Wolf.

Than try another range. Most people are "stocking their ammo" not blazing it on a range.  So there should be no crowds.

Our rifle range has a No Rapid Fire Rule, but you can at least load a full mag.

Shoot, clean,lube, repeat,...

[Bidah]

Find some Federal American Eagle as it should not be a whole lot more than the Wolf.  Better yet get some Winchester Q3131A or similar full power loads. Wolf is a bit lower power so some systems will not work reliably with it.  What is happening is there is not enough force to take the bolt all the way back to lock.  This would also be called short stroking.

If you have an adjustable gas system, yes you could just give it a bit more gas.  Just remember to run it back down when you get to regular ammo.

-Bidah

[Sponsor]

[tombogan03884]

 WITH AN EMPTY WEAPON, cycle the bolt by hand and watch whats happening.
When the bolt locks, does it catch on the mag follower to allow the catch to engage ? it may be a mag issue.

[Thanos]

I don't have a problem with the range, I am just not sure if it will do it with more than one round in in the gun or if it is something that will only happen with the magazine empty. I wanted to know if any of you had the same problem ever. I thought it might be the ammo, and it sounds like twyacht has had the same issues with the ammo before.

[Big Frank]

It sounds like it's short-stroking because there's not enough gas pressure. 

[CDR]

I would try some Federal Lake City XM193 5.56 ammo.  This is military ammo and loaded hotter than most but a really superb round.  I just bought a thousand rounds a few weeks ago and its going to be difficult to move to something else.  If you have the same problem with XM193 you can definitely rule out ammunition as the issue as this will certainly produce enough gas pressure to secure the bolt carrier.  I think the previous response from Tom with respect to a mag follower issue is a definite possibility, but I assume you've cycled through a few different mags trying to isolate the problem.

Good luck.

[MAUSERMAN]

I could be a problem with the gas rings or the seal of the bolt carrier coupled with bad rings.