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Joined: Oct 2003
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OP
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Posts: 631 |
I had a Winchester primer leak in the corner of the primer cup a couple weeks ago in my Model 70 7-08. This was with a moderate load. It is a couple grains below max. I shot silhouette with the rifle yesterday and had three more do the same thing. This was also with moderate loads that have never given any trouble. After I saw it I looked at the bolt and found a pit in the bolt face.
I would like to know what the best way to fix it is. It looks like it would clean up with about .010" taken off the bolt face. Is that good way to go or would it be better to weld the pit and reface the bolt?
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Joined: Nov 2007
Posts: 4,320
Campfire Tracker
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Campfire Tracker
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My rifle's bolt has been pitted for years and years, and the pitting does not seem to hurt a thing. Of course, it would depend on the depth of the pitting.
As for what causes pits? It is a weakness in the cup, allowing the hot, high pressure to blow out a small in the primer.
What did it for me was a carton of Rem. 9 1/2 primers. I decapped a few of them and sent them to Rem. Rem. did have the decency to write me back and explain that they had revamped the machinery that makes primer cups. This was to eliminate a step in the manufacture of the primers, but it caused a weakspot in the cup. Thus blowback and a pitted bolt face.
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Joined: Oct 2008
Posts: 621
Campfire Regular
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Campfire Regular
Joined: Oct 2008
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All primers leak eventually. In a new case with a smooth primer pocket, the first primer will seal pretty well, but the first time the case is reloaded, the old primer will leave small scratches in the primer pocket wall as it is pushed out. Primer pocket cleaning tools will often leave more damage. The next primer will seal less well and the situation gets worse over time. Pitting of the bolt face is unavoidable, but usually doesn't cause a problem untill the firing pin hole starts getting involved. Then the bolt face can be repaired by inserting a bushing with the correct firing pin hole size.
RAN
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Unless you have a lathe and a steady rest, you will have to pull
the barrel and use a tood designed for this. Depending on how
much metal you remove to get rid of the pits, it will change
the headspace, creating another problem. Suggest that you
have someone experienced in this procedure to do it.
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Joined: Jan 2001
Posts: 59,121
Campfire Kahuna
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Campfire Kahuna
Joined: Jan 2001
Posts: 59,121 |
I had a Winchester primer leak in the corner of the primer cup a couple weeks ago in my Model 70 7-08. This was with a moderate load. It is a couple grains below max. I shot silhouette with the rifle yesterday and had three more do the same thing. This was also with moderate loads that have never given any trouble. After I saw it I looked at the bolt and found a pit in the bolt face.
I would like to know what the best way to fix it is. Like another said, a pit won't really affect a thing. It looks like it would clean up with about .010" taken off the bolt face. That must be some pit.. I have doubts it's that big; not saying it isn't, but .010 is a LOT. Is that good way to go or would it be better to weld the pit and reface the bolt? BT99's right - it takes a lathe and a bolt fixture to machine a new face on the bolt.. And that WILL affect headspace - which means the barrel will have to be set back and the chamber deepened.. You're looking at quite an expense to correct what is, for the most part, a mere aesthetic anomaly..
Ex- USN (SS) '66-'69
Pro-Constitution.
LET'S GO BRANDON!!!
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Joined: Oct 2003
Posts: 631
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OP
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I have the lathe(and steady rest). I fit and chambered the barrel and I have the reamer and head space gauges. Oh, I also have a barrel vise and receiver wrench. It will only cost time and I will be tinkering with something anyway.
I'll try a different batch of primers before I do anything. I can use this batch for cast bullet loads where they should be fine. I just wanted to know how much I can take off the bolt face of a push feed Model 70 without creating another problem? Incidentally I also have the Tubb firing pin so I can easily adjust firing pin protrusion if necessary.
Thanks for the answers.
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Joined: Dec 2004
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Campfire Outfitter
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Campfire Outfitter
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I would happily recommend Greg Tannel also.
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Joined: May 2008
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Campfire Ranger
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Campfire Ranger
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I would happily recommend Greg Tannel also. I'm not sure I would given this level of "craftsmanship". Don' know who makes the Gre-Tan assembly nor do I care... I do know that numerous assemblies which were purchased that don the name "Gre-Tan" would not screw in all the way into a Remington bolt... They were about 1/8 of a turn shy from allowing the cocking piece to engage properly on the bolt... Returned the assemblies and received new "Gre-Tan" assemblies that out of 4 units one worked and three would not... Bolt and Gre-Tan assembly were sent into Gre-Tan for proper fitting... One would think that the Shroud face would have been shaved down slightly to allow the assembly to be screwed in for the cocking piece to engage as it should... Instead the bolt was ground down and looks like schit... I've purchased 6 assemblies from PT&G that are NOT Gre-Tan units and all work just fine... YMMV... Ground down bolt... ![[Linked Image]](http://i274.photobucket.com/albums/jj252/elkhuntinguide/Guns%20and%20Ammo/001-12.jpg)
The Chosin Few November to December 1950, Korea.
I'm not one of the Chosin Few but no more remarkable group of Americans ever existed.
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Joined: Jun 2004
Posts: 886
Campfire Regular
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I have the lathe(and steady rest). I fit and chambered the barrel and I have the reamer and head space gauges. Oh, I also have a barrel vise and receiver wrench. It will only cost time and I will be tinkering with something anyway.
I'll try a different batch of primers before I do anything. I can use this batch for cast bullet loads where they should be fine. I just wanted to know how much I can take off the bolt face of a push feed Model 70 without creating another problem? Incidentally I also have the Tubb firing pin so I can easily adjust firing pin protrusion if necessary.
Thanks for the answers. It looks like you have all the stuff there to fix it up real good. Be sure to post some pictures.
"Hired Gun" Quickest and fastest all motor sand car on the planet.
3.008 at 104.8 300' of sand.
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Joined: Feb 2003
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Campfire Outfitter
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Cutting the pitting off a bolt face is like lapping scope rings.
Negative value added.
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps
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Campfire Tracker
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Campfire Tracker
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I seem to recall in one of the Video tapes on customizing mausers put out by AGI that they fixed some pitting on some of their bolt faces by making very tiny welds to fill in the pit, and then of course dressing it off. I don't know anymore about it than that, but the video of them doing it sure looked good.
Maybe you could find somebody locally that is set up for micro tig welding and give it a try.
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