White mountain crack

[Crows-R-US]

Could you please explain the how and why and the mechanics behind the overtightened bolt causing a lateral crack in the stock.

You answered most of your own question in your response #14. I totally agree it's a design flaw coupled with poor grain orientation of a relatively soft, loose-grained wood. It's a thin area of the stock with a lot of dead space between it and the lock. Walnut is a good wood for stocks but, it's relatively soft and loose-grained. When you over-tighten the lock bolt you're pre-stressing this already weak area even more. Combine this with the thin wrist, excessive drop at the wrist of the White Mountain, and the heavy loads people like to shoot in their fast-twist barrels & it just don't take much to set things in motion.

And I also agree with you that 'prevention is the key' and not over-tightening the lock bolt is just part of that prevention. After all, all the lock bolt has to do is keep the lock from falling out so just no need whatsoever to over-torque it.

 

[chorizo]

An unrelieved bolt hole is really the issue. If you tighten the bolt, of course, it provides a much more unforgiving tension to allow it to pass on lateral force to make it into a splitting wedge. Leaving the bolt loose simply is treating the symptom and not the problem. I can see where the Seneca was the genesis of this myth because, in fact, the design of the washer in a hole can cause cracking from overtightening. The current design with the washer sliding on top of the stock would not. It has lead to the MYTH (held over from the Seneca) that over tightening the bolt will cause a crack, whereas it is the bolt itself banging up against the stock in the undersized hole the causes the crack in the non seneca models

The tang solution by Eric, along with bedding and relieved oversized bolt holes...tang and lock...should solve and prevent any problems. The poorly designed tang/trigger screws contribute significantly to cracks in other areas along the tang.

I have never seen that type of crack in the SxS sidelocks that have a bolt through a much more narrow dainty stocks even in the heavy game/live pigeon shotguns and both locks pull together fairly tight. But then again the through bolt hole is relieved on each and every one of them and it prevents the bolt from banging up against the wood. Now I have seen at the back of the locks where cracks will form, but that is because of either poorly inletted locks or a loose through bolt or a combination of both.

Hopefully Eric will wade in also as he has extensive experience in this.

 

[bat119]

The crack on the WMC is identical to the one on mine possibly when stress is applied from the sides the recoil impact causes the grain to separate? The cracks follow the grain in the wood I think my next project will be bedding my Hawkens for prevention, I use JB weld cheap insurance.

 

[chorizo]

The crack on the WMC is identical to the one on mine possibly when stress is applied from the sides the recoil impact causes the grain to separate? The cracks follow the grain in the wood I think my next project will be bedding my Hawkens for prevention, I use JB weld cheap insurance.

No. It is the bolt banging up onto the wood in the screw hole. Nothing to do with tightness of the through bolt.
Make a oversized hole and it won't bang up against the wood.

 

[chorizo]

Hmm double post

 

[planefixer da50]

do a piller beding of lock bolt. use the threaded tube used for lamps that the cord snakes through. drill stock to screw onto it with slow set epoxy. want to just barely touch lock plate when drawen tight. have done this to a couple friends. no cracks using max loads if they want .

 

[Crows-R-US]

Believe what you want but, it's a simple fact that all the lock bolt has to do is hold the lock steady and in place so there's absolutely no need to stress an already weak spot in the stock design by over-torquing the lock bolt. And properly tightened, the lock bolt doesn't do any "banging against the sides of the hole".

 

[chorizo]

And properly tightened, the lock bolt doesn't do any "banging against the sides of the hole".

Yeah, right. That's why the almost never crack. Simple solutions for simple minds.

 

[tgfrench]

At the risk of being royally flamed. I'm going on record stating that I see minimal lateral forces being applied to the lock screw in the shock of firing being the root cause of all evil.
Over compression of the screw, yes, in an area that has been overly inletted, absolutely!
Inletted brass or iron compression panels opposite the lock to alleviate this issue non existent in lower end rifles.
I submit that the lateral forces applied to an overly machined Inletted breech and lock along with poor design of the whole area contribute as much as poor wood grain to this issue.

 

[Crows-R-US]

Yeah, right. That's why the almost never crack. Simple solutions for simple minds.

If your lock is moving around enough for the bolt to bang around you've got far worse problems than a lock bolt. And if you want to talk about 'simple minds' talk to the fellow in the mirror.

 

[BadDaditood]

From the title of this thread I was expecting something completely different!?!

 

[64Springer]

From the title of this thread I was expecting something completely different!?!

Yeah.

Crackhead Hunter spending a day in the snow covered Rockies.

 

[Bad Karma]

do a piller beding of lock bolt. use the threaded tube used for lamps that the cord snakes through. drill stock to screw onto it with slow set epoxy. want to just barely touch lock plate when drawen tight. have done this to a couple friends. no cracks using max loads if they want .

I’ve used pieces of aluminum arrow shafts

 

[kyron4]

From the title of this thread I was expecting something completely different!?!

I find a 1/3 of the post titles here very misleading.

 

[TDM]

I find a 1/3 of the post titles here very misleading.

No! Say it isn’t so!