Ruger SFAR small frame 308, 6.8 pounds

[WindstormSCR]

@MinistryOfTruth have you tried any ammo from a completely different batch lot#?

could be Hornady had a small run of oversized primer pockets that were just enough to blow out with the internal ballistics of 6.5CM. I know that was a contributing factor to the issues with the 6.5CM SCAR

other thing you might inspect is how close your chamber is to minimum spec, kissing it gently with a fractionally larger reamer might give the case enough room to do its thing without popping the primer.

 

[doubloon]

have you tried

FWIW, my 308 SFAR blows primers with Core-Lokt and Hornady hunting rounds that both function fine in the DPMS and the bolt gun

After enough rounds it also suffers from sticking cases and torn rims with virtually any ammo I've tried.

I'm currently of the mind that the chamber is the correct place to focus for a solution.

 

[MinistryOfTruth]

I am going to use a throating reamer on it next.

 

[MinistryOfTruth]

@MinistryOfTruth have you tried any ammo from a completely different batch lot#?

could be Hornady had a small run of oversized primer pockets that were just enough to blow out with the internal ballistics of 6.5CM. I know that was a contributing factor to the issues with the 6.5CM SCAR

other thing you might inspect is how close your chamber is to minimum spec, kissing it gently with a fractionally larger reamer might give the case enough room to do its thing without popping the primer.

I have new lot and old lot stuff. Both do it.

 

[EzGoingKev]

Out of curiousity, have you chrono'd any of it?

 

[MinistryOfTruth]

Out of curiousity, have you chrono'd any of it?

Yes. quite a bit. ES and SD are good and in line with my other 20” ARs.

To be exact my JP 20 did 2534fps with this ammo. This gun does 2534fps with this ammo.

 

[EzGoingKev]

I was curious to see if you were getting higher than normal/expected velocity readings.

 

[MinistryOfTruth]

I was curious to see if you were getting higher than normal/expected velocity readings.

Makes perfect sense and I wasn’t watching it closely till you said something. I had brushed it off as a nonissue but only took half a look.

 

[MinistryOfTruth]

Just ordered the reamer for the throat. I notice my throat is very very slightly off perfectly cut. There is a shadow of rifling on one side.

I may use cold blue on the throat before I cut so I can clearly see what happens