SFAR hates one brand of M80 ball

[MadDuner]

I have a new 20” Ruger SFAR.
I took it out to sight it in a few weeks ago, and all was great. No issues whatsoever.

Yesterday I took it out, with two full-size .308 AR10’s, while verifying 100yd centers with different ammos. The good ammo - 168gr Hornady Superformance was accurate and golden in all three rifles. I also took 147gr M80 milsurp from Malaysia, Switzerland, and Germany. The two AR10’s ate everything without issues.

The SFAR ate all except one.
It failed to eject with only one brand of ammo… and it not only failed to eject, but had to be mortared to get the BCG freed, then each brass pounded out with a dowel rod.

WTF is going on?
The other weapons had no issue with the ammo at all. Only the SFAR had an issue with it… while acting perfectly normal in operation with all other brand presented.
There are no odd marks anywhere else on the brass.

Anybody have any ideas?

 

[XLR308]

Damn that looks nasty, no damage to rifle i hope.
Looks like it is powder issue and port pressure was still way the hell up and trying to rip the case from the chamber.

 

[highbclowgr]

View attachment 8116716I have a new 20” Ruger SFAR.
I took it out to sight it in a few weeks ago, and all was great. No issues whatsoever.

Yesterday I took it out, with two full-size .308 AR10’s, while verifying 100yd centers with different ammos. The good ammo - 168gr Hornady Superformance was accurate and golden in all three rifles. I also took 147gr M80 milsurp from Malaysia, Switzerland, and Germany. The two AR10’s ate everything without issues.

The SFAR ate all except one.
It failed to eject with only one brand of ammo… and it not only failed to eject, but had to be mortared to get the BCG freed, then each brass pounded out with a dowel rod.

WTF is going on?
The other weapons had no issue with the ammo at all. Only the SFAR had an issue with it… while acting perfectly normal in operation with all other brand presented.
There are no odd marks anywhere else on the brass.

Anybody have any ideas?


View attachment 8116714

Those .308 brass compounds could be too sticky for the SFARs chamber material and or tolerances.

Should extract fine even after 1000 rounds.

Any signs of over pressure?

 

[MadDuner]

Those .308 brass compounds could be too sticky for the SFARs chamber material and or tolerances.

Should extract fine even after 1000 rounds.

Any signs of over pressure?

No signs of over pressure.

I tried at every setting of the gas block. All damage to brass is from mortaring the BCG back - where it left the brass stuck in the chamber after ripping the thing open.

 

[highbclowgr]

No signs of over pressure.

I tried at every setting of the gas block. All damage to brass is from mortaring the BCG back - where it left the brass stuck in the chamber after ripping the thing open.

Did you fire thousands of rounds before this happened?

Is the gas key on the BCG good?

All I can think of is a super carboned up chamber or case buldging.

 

[XLR308]

The case head on the right in your picture looks like there was some brass flow into the ejector.
Have you measured the case dimensions on the problem cases and compared to the unfired dimensions ?

 

[MadDuner]

Did you fire thousands of rounds before this happened?

Is the gas key on the BCG good?

All I can think of is a super carboned up chamber or case buldging.

No.
Maybe 100 rounds total at this point.
I just pulled it apart and cleaned it. Wasn’t actually dirty.

 

[MadDuner]

The case head on the right in your picture looks like there was some brass flow into the ejector.
Have you measured the case dimensions on the problem cases and compared to the unfired dimensions ?

I haven’t yet.

Still confused about the ammo working in everything else, but not THIS rifle. And then the rifle being happy with everything else?

 

[Huskydriver]

Measure the HS on the ok m80 ounds vs that m80 brand and see if it's on the longer end.

If it is and your chamber is on the short end you can spike pressure

 

[XLR308]

I haven’t yet.

Still confused about the ammo working in everything else, but not THIS rifle. And then the rifle being happy with everything else?

Yeah thats kind of odd, was it the Malaysian ammo out of curiosity ?
If it was brand new and not commpletly clean i might question residue in the chamber left over from the nitride process but that generally leaves a smoked looking soot on brass that isnt there.

 

[MadDuner]

Yeah thats kind of odd, was it the Malaysian ammo out of curiosity ?
If it was brand new and not commpletly clean i might question residue in the chamber left over from the nitride process but that generally leaves a smoked looking soot on brass that isnt there.

I was wrong.
This ammo actually came from Bosnia.
I thought it was German.

 

[highbclowgr]

I was wrong.
This ammo actually came from Bosnia.
I thought it was German.

I wonder if you mix powder residues from all different types of ammo if it can get sticky.

 

[MadDuner]

I wonder if you mix powder residues from all different types of ammo if it can get sticky.

Interesting idea!

Here’s what the other ammo looked like…

 

[highbclowgr]

Interesting idea!

Here’s what the other ammo looked like…
View attachment 8116779

I think the one in the middle is 8x57 Mauser from Afghanistan.

Jk.

 

[MadDuner]

I think the one in the middle is 8x57 Mauser from Afghanistan.

Jk.

I saw that also....
1 or 7?
What could possibly go wrong?

 

[highbclowgr]

I saw that also....
1 or 7?
What could possibly go wrong?

Possibly not much.

 

[XLR308]

I saw that also....
1 or 7?
What could possibly go wrong?

I have seen similar, primarily Polish.
Their writing specifically numbers takes some getting used to.
@Huskydriver explanation seems the most plausable at this point.

 

[highbclowgr]

Figure it out yet?

 

[MadDuner]

Figure it out yet?

Not yet.

Since this rifle is happy with every other ammo I’ve tried...
For now I’ll just not put this type of ammo through it and come back to it at a later date to see if a thousand rounds through the thing changes anything.

 

[BCP]

It failed to eject with only one brand of ammo… and it not only failed to eject, but had to be mortared to get the BCG freed, then each brass pounded out with a dowel rod.

Poor ammo QC it's probably on the larger end of headspace would be fine a 7.62NATO rifle but not a 308 commercial. I've had the same problem with my DPMS SASS and M1A and various kinds of mil spec ammo.

 

[MadDuner]

Just thought to update this....
Only another 100 or so rounds through it, but no issues since I left the Milsurp M80 stuff at home.

 

[9.80mps2]

SalTech (Swiss) ammo does this in my Ruger SFAR. Real shame because it groups well in this particular barrel.
About 1:20 rounds it will fail to extract.
Aero M5E1 Cycles the ammo just fine, but despite a Criterion 18.5 barrel, does not group well with this $0.75 ammo.

 

[1911hombre]

Cuz....Ruger.

 

[BCP]

SalTech (Swiss) ammo does this in my Ruger SFAR. Real shame because it groups well in this particular barrel.
About 1:20 rounds it will fail to extract.
Aero M5E1 Cycles the ammo just fine, but despite a Criterion 18.5 barrel, does not group well with this $0.75 ammo.

308 win min headspace is 1.630, M1As I had were 1.632 for NM and I think 1.634 for standard. 7.62 NATO min headspace is 1.635. While that .005 doesn't sound like much it does make a difference when you have ammo made to one sizing spec vs the other. My guess would be that using lots of lube and shooting a few hundred rounds through it will "loosen" it enough to shoot whatever you want.

Orrr if you're in AZ I'll buy all your saltech and shoot it through my 716.

 

[MadDuner]

308 win min headspace is 1.630, M1As I had were 1.632 for NM and I think 1.634 for standard. 7.62 NATO min headspace is 1.635. While that .005 doesn't sound like much it does make a difference when you have ammo made to one sizing spec vs the other. My guess would be that using lots of lube and shooting a few hundred rounds through it will "loosen" it enough to shoot whatever you want.

Orrr if you're in AZ I'll buy all your saltech and shoot it through my 716.

And the Saltech shoots fine through mine, but not the Igman.