crossbolts

[Ontario Hunter]

I was under the impression that a rod thru the wrist was to prevent breakage from an accidental fall l, etc. I’m not sure I can see how it would stop a crack from recoil but perhaps.

Outward flexing of wood during recoil causes grain to pull apart and start cracking. Thinnest parts of the stock are bound to be at most risk of flexing. That's why we add crossbolts there. The areas around the magazine box and trigger are obviously the thinnest spots. Military rifles of relatively modest recoil were the first to adapt crossbolts ahead of the magazine box. Some early heavy thumper guns had simple pins across the area between box and trigger. Eventually it was determined that was not enough and dual crossbolts became the norm for heavy recoil rifles. Restricting flexing of wood in those areas meant that all the energy formerly absorbed there from flexing was transmitted intact to the next thin area of the stock, the wrist. Putting a bedded rod through the wrist helps conserve that energy for the much thicker comb and butt which are less likely to swell with recoil or succumb to swelling. The other option is to bed a metal rod across the grain in the wrist through the checkering (not very asthetic). Cracks typically start behind the tang on top. I'm sure you have noticed that heavy recoil rifles jump up, not down. Thus more of the recoil energy is transmitted to the top tang. I'm sure that's why most sources advocate drilling the hole for wrist rod down through the end of upper tang slot in the stock.

As to Larry Potterfield's video, I concluded he must have a MUCH steadier hand than me to manually keep an electric hand drill with extra long drill bit on track when drilling out the hole through wrist of very hard walnut stock. That's why I built a jig. If attempting to drill the hole freehand, I suggest first drilling a smaller diameter pilot hole with a short drill bit to start the 1/4" extra long drill bit.

 

[Viral_SIGness]

My .375 Ruger African cracked it's stock. I used a cross bolt to repair it, but I still ended up putting it on a .300 Win Mag.

 

[Ontario Hunter]

My .375 Ruger African cracked it's stock. I used a cross bolt to repair it, but I still ended up putting it on a .300 Win Mag.

Images I see online of Ruger African show two crossbolts. Did you add a third? Where?

 

[Grumpy gumpy]

There was a trend for a while to put a crossbolt through the wrist just behind the trigger in the spot where it starts to thin down.
And that fractured stock, I would like to see the other side as to me it looks like a bend fracture, ie; someone fell on it
Gumpy

 

[CBeck]

Outward flexing of wood during recoil causes grain to pull apart and start cracking. Thinnest parts of the stock are bound to be at most risk of flexing. That's why we add crossbolts there. The areas around the magazine box and trigger are obviously the thinnest spots. Military rifles of relatively modest recoil were the first to adapt crossbolts ahead of the magazine box. Some early heavy thumper guns had simple pins across the area between box and trigger. Eventually it was determined that was not enough and dual crossbolts became the norm for heavy recoil rifles. Restricting flexing of wood in those areas meant that all the energy formerly absorbed there from flexing was transmitted intact to the next thin area of the stock, the wrist. Putting a bedded rod through the wrist helps conserve that energy for the much thicker comb and butt which are less likely to swell with recoil or succumb to swelling. The other option is to bed a metal rod across the grain in the wrist through the checkering (not very asthetic). Cracks typically start behind the tang on top. I'm sure you have noticed that heavy recoil rifles jump up, not down. Thus more of the recoil energy is transmitted to the top tang. I'm sure that's why most sources advocate drilling the hole for wrist rod down through the end of upper tang slot in the stock.

As to Larry Potterfield's video, I concluded he must have a MUCH steadier hand than me to manually keep an electric hand drill with extra long drill bit on track when drilling out the hole through wrist of very hard walnut stock. That's why I built a jig. If attempting to drill the hole freehand, I suggest first drilling a smaller diameter pilot hole with a short drill bit to start the 1/4" extra long drill bit.

Images I see online of Ruger African show two crossbolts. Did you add a third? Where?

Early Ruger Africans only had one. Most cracking in the wrist as you described earlier is splitting cracks from the tang. All the energy transferred to that one small point of contact splits the wood like a wedge splitting firewood. Not a shearing crack from side pressure.

I agree that the crack in the wrist shown in the picture above looks like one that was fallen on.

 

[Ontario Hunter]

Early Ruger Africans only had one. Most cracking in the wrist as you described earlier is splitting cracks from the tang. All the energy transferred to that one small point of contact splits the wood like a wedge splitting firewood. Not a shearing crack from side pressure.

I agree that the crack in the wrist shown in the picture above looks like one that was fallen on.

That broken stock was well rebated away from receiver tang. I agree something else besides recoil probably caused the fracture.

A wedge splits wood by spreading the grain outward.

 

[Viral_SIGness]

Images I see online of Ruger African show two crossbolts. Did you add a third? Where?

My African only had one, and it was teeny tiny, and wasnt doing the job. Wish I had all the pictures still, but no idea where they are now.

Anyway, its the bottom one in this picture, under the BLACK Alaskan. Both of my rifles were early models.

Of course I sold the Alaksan and now my African has the Ghille Green stock.