sig 716 patrol brass shavings everywhere

[Jodirt]

I am new to the "ar platform" and having problems.
My sig 716 is filling up with brass shavings behind the ejection claw, inside the bolt around the firing pin and in the chamber area.
The brass is deforming into the ejector button hole then shears off when the bolt rotates leaving little bits of brass everywhere.
I have had this problem with federal ball ammo, pmc, fiocchi, federal premium, nosler custom.
It does not matter if it's 7.62 nato rounds or 308 hunting rounds or reloads.
I have talked with the manufacturer and been told that this is normal case wear for a piston gun.
having limited experience with the "ar style operating systems" I figure it can't hurt to ask for your opinions, is this a normal thing for all piston guns ?

 

[Jodirt]

pic of some brass

I am new to the "ar platform" and having problems.
My sig 716 is filling up with brass shavings behind the ejection claw, inside the bolt around the firing pin and in the chamber area.
The brass is deforming into the ejector button hole then shears off when the bolt rotates leaving little bits of brass everywhere.
I have had this problem with federal ball ammo, pmc, fiocchi, federal premium, nosler custom.
It does not matter if it's 7.62 nato rounds or 308 hunting rounds or reloads.
I have talked with the manufacturer and been told that this is normal case wear for a piston gun.
having limited experience with the "ar style operating systems" I figure it can't hurt to ask for your opinions, is this a normal thing for all piston guns ?

1

 

[Killsnugglebunny]

No way. I have probably put 1k through mine at a minimum, and yeah occasional brass flake here or there but not like you are describing. I reload too so that would bug me out.
But to be clear mine definitely does not do that.
Early productions had issues, youtube and sigtalk touch on it.

 

[BCP]

The gas system is adjustable you probably have it wide open so the bolt is rotating a bit too early. Also that ammo is loaded way hot, just look at that one in the top right with the gray around the primer. That is gas blowing past the primer.

 

[Jodirt]

haven't figured out how to post comments or pictures very consistently yet.

The gas system is adjustable you probably have it wide open so the bolt is rotating a bit too early. Also that ammo is loaded way hot, just look at that one in the top right with the gray around the primer. That is gas blowing past the primer.

If this goes through I would like to thank everyone for the input.
The gas system is in the normal position, not wide open.
I have not yet tried the lowest position being for a suppressor as I do not have one, I assume this setting is just a little bit milder?
as far as the ammo being very hot. Good point. But I have had this problem with a wide variety of factory ammo it doesn't matter if is
7.62 nato or 308 of many different types and bullet weights.
The only rounds that have not been a problem are hand loads at the very lowest powder charge.
My manuals suggest 39-43g of imr 8208 xbr with 168g bullet
I have worked up loads from 39g to 41.5g I increased my charge .5g for each test batch.
I found only the 39g batch hadn't caused any significant damage.
CCI primer, IMR8208XBR powder, 165g Hornady A-Max, new Hornady match brass.
I have played with case resizing from full length , small base, and just setting the shoulder back .003 on once fired.
Still consistently damaged.
I have read about some sig 716 rifles being made with a new bolt that have 2 smaller ejector buttons, I can't help but wonder if this may resolve my issue ?
Any more suggestions would be appreciated, thank you for your time.

 

[BCP]

Give the suppressor setting a try. A U-shaped indentation is normal but if that U-shaped is missing brass then I'd say it's running a little too hot/overgassed.

 

[Jodirt]

Okay I'll give it a try next time it stops raining.
But just for the record the u-shape area isn't indented it's raised.
Once again thank you for your time.

 

[cal50]

Check the ejector that it moves freely and is not binding. A slight radius on the edge makes it easier on the brass, if its got a sharp edge steel wins over brass and will shave it and mark it up.
When I got my gun and stripped and cleaned it before firing my ejector hole was loaded with some sort of liquid crap and the plunger moved more like a piston. I removed it, cleaned and lightly oiled it. After my 1st outing I then nipped a coil and half off the ejector spring to tweak my ejection pattern where I wanted it.

Other than a bunch of factory dirt , lube and brass shavings once I cleaned and lubed my 716 I do not see any more brass or droppings anywhere.

 

[FALex]

I'd check your feed ramps and the feed lips on your magazine for any sharp edges. I'd also look at the extractor for the same - sharp edges.

I know you stated you were newer to the AR platform. Are you running it with enough lubricant?