Sig 716 Patrol Rifle Malfunction -- NEED HELP!!

[1371MARINE]

Ok Gents here's the background and issue;

Purchase this rifle in Dec. 2012. It sat in the safe until yesterday's maiden voyage to the range.
I disassembled it to wipe off the excess factory and storage oil before running it.
Field stripped the BCG, wiped everything down, reassembled it.
Inserted an empty mag and ran a function check... everything performs as it should.
Locked the bolt back, insert a full mag of PPU ammo and slam one home.
The round did not fully seat in the chamber hence causing the bolt not to fully lock.
So I try to seat it with the forward assist a few times, but no luck.
Next I try to extract the round but the lugs on the bolt are behind the lugs on the barrel extension because it did not fully rotate and lock in the first place.
So now I have a live round stuck and can't go forward or back with the BCG.
Does anyone have any advice to offer?? I know it's under warranty, but I can't ship it back with the live round in place per Sig's owners manual. I haven't contacted them since it's the weekend so I was hoping someone out there could offer a solution to get the round out before I move forward. Thanks in advance for any help.

 

[jwh20]

A friend has one of these and had the exact problem. BTW, these are REALLY nice rifles but in his case we were using surplus ammo and at least 50% of the rounds did exactly that. They failed to chamber fully and the bolt gets stuck just before going into battery. You can't force it forward and you can't pull it back with the charging handle. The only way out is to carefully use a tool to pry the BCG back far enough that it unlocks.

We switched to some better quality ammo (Winchester White Box .308) and it's been 100%. My guess is that it will loosen up a bit over time but after measuring a number of the surplus rounds they were quite inconsistent in their sizing. The Winchester was all really tight tolerance.

I don't have any experience with PPU ammo but You might pickup a few boxes of different .308 and see if yours likes one brand vs. another.

 

[1371MARINE]

I thought of doing just that(Prying it back) but it's lug on lug now. Won't it have to rotate as well to unlock?

 

[red_zr24x4]

In a safe location, pull baçk on the charging handle while smacking the butt on the ground. The momentum will usually get the bolt unstuck.

 

[USMC-Johnson]

Mortar tube it...basically put the weapon on safe...grab the charging handle like a man and slam the butt on a hard surface while pulling on the charging handle...also not a bad way to clear a brass over bolt malfunction either.

 

[M67]

Yup, mortar it, hard.

Oh, for a 308 AR, unless you're certain the rifle is a little dry and the BCG didn't quiet lock, don't use the forward assist. 308s use man springs, lot more power behind them. If a round doesn't want to be in the chamber for a 308, don't force it.

 

[1371MARINE]

Yup, mortar it, hard.

Oh, for a 308 AR, unless you're certain the rifle is a little dry and the BCG didn't quiet lock, don't use the forward assist. 308s use man springs, lot more power behind them. If a round doesn't want to be in the chamber for a 308, don't force it.

I was a little skeptical on this approach, although I've used it many time in the Corps, given it was a new rifle and I could potentially damage it further and void the warranty. I finally talked myself into it and it didn't take very much force. The round popped right out and didn't show any signs of FTF or FTE. I pulled the bolt and out of curiosity dropped that same round in the chamber, it fell right in. Others did too. So all in all it turned out to be a good day with the promise of a "near in the future" range trip to see what ammo does or doesn't run in this puppy. Thank you all for you comments and help. Semper Fi !!

 

[M67]

308 ARs when they're new can be picky or temperamental. My old DPMS was picky, especially on powder. My POF P308 has been picky as well, suppressed and unsuppressed, I just haven't had the time to really work on loads for it. And unfortunately, the "plinker loads" I developed for the DPMS won't always run properly or even chamber in the POF. Shoot it, break it in, and if it doesn't chamber, mortar it and try it again, try avoiding to use the forward assist.