Gunsmithing SPR Boltface

[223ai]

I am currently having a .308 built on an FN SPR action from CDNN using a Brux 10 twist finishing at 20 inches, CDI Mag system, and a McMillan A3 stock. I like the action, and it was surprisingly smooth from the get go. Interestingly enough, I've read of some people having primer cratering issues with these actions and I think my gunsmith might have found the culprit:

My gunsmith had this to say:

"Will cause primer cratering that will look like pressure signs. I can bush the hole to make it crisp as it should be. I would go ahead and go to a .062" diameter pin since we are bushing it(further eliminates cratering). I can turn your stock pin down to .062"

Here are the after pics:

He also found that firing pin protrusion was only about .040", should be .050-.060", and corrected that.

Just wanted to share the pics, as I thought they were really interesting.

Best,
Josh

 

[cal50]

Re: SPR Boltface

Nice work.

 

[Jester8]

Re: SPR Boltface

Nice, do you have some before and after pics of the brass?

 

[223ai]

Re: SPR Boltface

No pics of the brass as I haven't fired a round with this action. My post should have read that some other people with SPR actions have some cratering "issues". I think the brass marks are from test firing at the factory. I bought the action from CDNN Sports.

 

[yavapai kid]

Re: SPR Boltface

Good information, thanks.

 

[BOLTRIPPER]

Re: SPR Boltface

what camera did you use to take them fine pictures..?

 

[223ai]

Re: SPR Boltface

Bolt -

Some kind if microscope rigged up with a camera attachment. This gunsmith has serious attention to detail....

Josh

 

[Jester8]

Re: SPR Boltface

Yeah those are damn good pics, good thing you have a smith that pays attention. Is it surprising that FN would let this slip? Just thinking out loud here.

 

[Casey Simpson]

Re: SPR Boltface

I'm not surprised; it's just an ole' factory rifle. And most of the pin holes in bolts of factory rifles are too darn big. The pin hole in my AI/AE is too big and needs bushed. CCI#41 primers compensate for the misstep in manufacturing the bolt. Tubb's rifles don't have this problem.

 

[duey1267]

Re: SPR Boltface

What is the name of the smith that did the work?? Great looking job

 

[Casey Simpson]

Re: SPR Boltface

Ditto Duey.

 

[Bacarrat]

Re: SPR Boltface

Kenny Porter. Local guy that doesn't builds rifles for a living but heart pumps. He also builds parts for one of the best known shooter out there...

 

[223ai]

Re: SPR Boltface

Sorry for the delay, we are in Napa pounding wine right now....


Bacarrat nailed it, Kenny Porter is his name.