Home Forums Hunting & Shooting Gunsmithing Bolt Face Cratering

Had some primers undersized that leaked and now have significant cratering matching the OD of the primer.Unfortunately this is a dolled up Pre 64 Win. 70 in .270 and I'm sure has affected the guns value.
Can this be neatly fixed and if so who?
This was a major brand of primer that I've had good results with in the past.Have contacted them but don't really expect much help. Thank You!

Winchester?

There are several top gunsmiths that bush firing pins, so yes it can be fixed.

I had the same problem only with several firearms! I spoke to one gunsmith who said I needed to send it back to the manufacturer for a new bolt? I hope a gunsmith could fix this to save the headache of sending out several firearms to be fixed.

Competent benchrest gunsmiths regularly bush firing pin holes, it's a fairly straightforward lathe job and no need to send the gun back to the factory for a new bolt.

Especially as a new bolt will likely require the headspace to be reset which means setting back the barrel a thread or facing the bolt.

+1
If it's Winchester, the problem is not undersized primers, it's that the brittle primer cups crack, just FYI. This is important to figure out, because if it's the Winchester primer issue, they will replace the primers and pay to fix the bolt.

Also, fixing pits around the OD of the primer is different than bushing the firing pin hole. Don't ask someone to bush the firing pin hole and expect that to necessarily fix the bolt face pits.

I figure it will be a pain in the arse to get the bolts fixed but hoping it won't be!

Interesting thread, Gentlemen.

I pretty much stick with older single shots, and have bushed most ALL of them,...a variety of reasons therefor that have no bearing here,...

Tech question, ...pure and hopefully simple, regarding this specific job

What would be the actual thickness of the bolt's face,
...e.g. how much material lies between the vertical plane, and that area where the firing pin's recess first begins ?

Thanks in advance.

Greg

The bolt face could be TIG welded and machined, probably less costly than bushing.

Bolt face catering by primer leakage won't be fixed by firing pin bushing

Yes they were Winchester primers,Sharon at Winchester is being very helpful.
I took a good look at the bolt face and it looks like a .265" cut would clean up the damage and in the process leave a shallow shoulder.Drill all the way through the bolt firing pin hole and tap 10-32.Use piece of .265 drill rod and machine the shank and thread 10-32,drill through .080" diam. for new firing pin hole.Screw this gizmo in with red locktite and carefully machine the excess flush with existing bolt face.
Much like bushing strikers in shotguns.The wall thickness of material behind the bolt face is about .250", plenty to work with.

Nnnnnoooo, unless you want it to look like a hack job.

Go to Jim Bordens web site. He has complete instructions along with diagrams there. You want a headed bushing that the O.D. of the head is slightly larger then the cash head, counterbore the bolt face aprox .100" deep for the bushing. It will give a more homogeneous look, you won't be able to see the insert once it's faced off.

Lovin' that !

....as far as threads go, I lean toward VERY fine, 40 TPI and up for this sorta' play,....32 TPI is just too damned coarse.

GTC

If you're worried about depreciation from the cratering a visible repair will make it worse. A pressed in bushing will hide where a threaded one will always have a pit and line where the threads meet. The Borden repair would look nice. Greg Tannel does a nice job too.

For a rifle worth $3,000+ I would replace the bolt. Midwest Gun Works has them. For a rifle worth less than $2,000 I really doubt a pitted bolt face is going to change the value as much as replacing the bolt is going to cost.

It's a cosmetic mark that is not really noticed unless you are looking for it. A ding in the exterior metal, a cracked or chipped stock would devalue a collectable rifle much worse.

The gun will be going to GreTan as they come highly recommended.Winchester has been very accommodating and I do appreciate there concern.There is no visible serial number marking on the present bolt so don't know if it is the original.This rifle was refinished in rust blue and the marking may have been buffed off,don't know,don't care.It is a keepsake to me!

I was going to suggest GreTan

Thanks for mentioning Gre-Tan. I talked with Greg last week and sent off a Ruger M77 eroded bolt yesterday. He said 2 to 3 weeks and cost from $90 to $150 depending on damage.

The bolt was sent to Gre Tan and returned in approx. a weeks time.It looks to be an absolute first class repair,checked headspace and everything fine.
This was a pre64 bolt and the ejector slot also needed to be recut as the new bushing extended into the slot.Cost was $125,couldn't be happier and Gre Tan is to be commended!

I think you sure be totally sure that it was bad primers that caused the erosion. Over length cases or severe copper fouling can cause high enough pressures to blow a primer and cause erosion. Case length gauges and a case trimmer are your friends. So is Wipe Out and some elbow grease. Fix the cause, not just the symptom.

If you do a search about Winchester large rifle primer leaks, you'll see it's not a problem of headspace, etc. It's a known problem of weak spots at the corner of the primer face and the primer edge. I have a couple of rifles with etched bolt faces that occurred with starting loads and spotless bores (I call it "Wipeout clean"). I was really questioning my loading procedures until I started seeing other examples (photos) of the exact failure I had experienced.