Ruger AR556 occasionally not going into battery...

[Balrog]

I think I know the answer, here but let me describe my problem, and y'all tell me what you think.

I shot a new Ruger AR556 for the first time today. I was shooting 55g FMJ loaded to NATO specs.

I did not clean the gun before shooting. I took it out of the box, inspected the bore, loaded a magazine and started shooting.

No problems for the first magazine.

On the 2nd magazine (probably around round #40), I started having problems with bolt not going completely into battery. It would almost completely close, but when I pulled trigger, I would just get a "click". In order to get the bolt open, I had to do the pogo stick move, ie, bang buttstock on hard surface while pulling back on charging handle.

What do ye say the problem is?

 

[Rod47]

Lack of lubrication. Read the owners manual for product suitability.

 

[buba68]

AR's like to run wet especially new ones during break in. I would take it down and clean it good and lube the bolt carrier until the oil is almost dripping off of it. That should solve your not going into battery problems.

 

[FL-NC]

Lube, possibly magazine. I lube my AR's with white lithium grease from auto zone.

 

[mshootnit]

reloads or factory ammo?

 

[sequins]

I had the same issue. Lubrication solved it. The chambers on the AR-556 are TIGHT

 

[edwardware]

. . . the pogo stick move, ie, bang buttstock on hard surface while pulling back on charging handle.

Mortaring the rifle.

What do ye say the problem is?

Like that the operator didn't lube it, esp the cam pin and cam surfaces.

 

[ms6852]

The chambers on the AR-556 are TIGHT

This could be the issue. As others have stated lubrication is needed and possibly cleaning the chamber out. Powder residue may cause the bolt to not go into battery if the chamber is tight. The gap between case and chamber allowed vary and the gap may be about .006. A piece of powder residue no larger than a piece of copy paper measuring .007 thick can be enough not to allow the bolt to close and lock.

So cleaning the bcg and chamber should take care of your issue.

 

[BBarn]

I've had the issue a few times with my reloads in a couple of ARs. Corrected by sizing cases completely with standard sizing die (adjusting sizing die for contact between shell holder and die bottom with a case in the die).

 

[Balrog]

I shot the gun more today after cleaning and lubing. I think the issue was an unlubricated and dirty BCG and chamber, and using reloads that were slightly longer than the gun wanted.

 

[jeepnik]

Probably nothing wrong a little lube and a smarter operator won't fix. Seriously, new, right out of the box, and you're surprised it didn't function 100%.

 

[buba68]

I think I know the answer, here but let me describe my problem, and y'all tell me what you think.
I shot a new Ruger AR556 for the first time today. I was shooting 55g FMJ loaded to NATO specs.

I did not clean the gun before shooting. I took it out of the box, inspected the bore, loaded a magazine and started shooting.
What do ye say the problem is?

Are you reloading your ammo? Don't know what dies you are using but most of the AR's do better with small base resizing dies. The small base dies will help if your chamber is on the tight side. Like everyone has told you and you found out keep the BCG very well lubed and you should be good to go.

 

[Balrog]

Probably nothing wrong a little lube and a smarter operator won't fix. Seriously, new, right out of the box, and you're surprised it didn't function 100%.

Oh, I didn't realize I said I was surprised. You will have to point out where I said I was surprised.
Turns out though, I think it was my reloads being a little long, and not the fact that I shot the gun right out of the box. After shooting the gun more without cleaning, it runs fine with factory ammo, but one batch of my reloads is a problem for it, and the OAL cartridge length is a hair longer than I should have made them.

 

[Peakbagger46]

OAL of your cartridge is a possible cause of your issue, BUT, cases that were not full length sized all the way down to spec is the more likely culprit IMHO. It might be a good idea to invest $20 or so in a case go/no go gage.

 

[Riomouse911]

Sounds like you found the issue, it’s common with semi-autos to be cranky with ammo slightly out of spec. .

Stay safe.

 

[earlthegoat2]

Problem is solved it appears but whenever a reload is in play, a test with factory ammo should be one of the first steps.