crossbolts

[thoma018]

A bit of explanation requested and needed...newbie here so bear with me and embellish me with info and links to rifle makers/manufacturing if you will.
I see most large caliber (375 and up) with crossbolts in the stock, sometimes one but mostly two. I always assumed they some how provide strength to the stock but then I see rifles of large caliber that do not have crossbolts. School me on the why's and why not's.
Thanks

 

[5shot]

To reenforce thin sections of the stock to prevent cracking. Some action inlets may not have the issue and thus no cross bolts?

 

[mdwest]

the areas behind the recoil lug and in front of the trigger are subject to absorbing much of the recoil from a rifle shot.. on heavy caliber rifles crossbolts are a means for reinforcing the stock in those key areas..

this video shows how crossbolts are installed and does a good job of explaining why they are needed and where they should be installed, etc..etc..

 

[grand veneur]

Unfortunately, they do not prevent the cracks of the pistol grip.

Rifle caliber 460 Weatherby Magnum which also has two crossbolts. The crack is clearly visible on both side.

 

[thoma018]

@mdwest, thanks cool video.
@grand veneur --how does one assure there is no pistol grip cracking ?

 

[mark-hunter]

School me on the why's and why not's.

Later edition of ZKK 602, 375 that I have has an inlet in stock forend, and connecting screw. Price of this is barrel that is not free floating. (old fashion design) I was entertaining myself to install crossbolts and make free floating barrel.
But the gusnmith suggested not to do, and rifle has acceptable accuracy. So, I kept it as it is.

 

[mdwest]

Unfortunately, they do not prevent the cracks of the pistol grip.

Rifle caliber 460 Weatherby Magnum which also has two crossbolts. The crack is clearly visible on both side.
View attachment 669884

Also doesnt help with cracking behind the tang with happens with frequency in some models of rifles..

 

[mdwest]

@mdwest, thanks cool video.
@grand veneur --how does one assure there is no pistol grip cracking ?

There are methods for reinforcing pistol grips and the area behind the tang.. but more often than not what you see is repairs to those areas after a crack develops rather than a preventative measure being put in place ahead of time..

A common "fix" for pistol grips is to have a rod installed upward through the pistol grip.. much like a crossbolt, it will absorb recoil, and can easily be hidden with a decorative pistol grip cap..

bedding the action with a high quality bedding compound and paying extra attention to the area surrounding the tang is a decent way to reinforce that area...

 

[Ontario Hunter]

Crossbolts keep the wood from flexing outward during recoil which can lead to cracking. Weatherby pioneered "internal crossbolts" which can't be seen externally. This amounts to hollowing out crosssections internally and reinforcing with a piece of threaded rod imbedded in fiberglass.

For wrist reinforcement I drill down into the wrist from end of tang slot. Most use 1/4" threaded rod again embedded in fiberglass. Here's the jig I made to drill out the channel for wrist rod. Drill is in the jig ready to start. I could have cut the drill shaft off shorter to help prevent wobble.

Slots in the stock at end of tangs, both top and bottom, should be "rebated" so there's a small gap between end of tang and wood. This will help keep cracks from starting in those spots.

Here's the jig for drilling out Winchester engraved crossbolts.

And here's the finished product.

 

[Major Bonkers]

Every Mannlicher-Schönauer in .458 Winchester Magnum that I have ever seen (I own one) has a broken grip (American)/ hand (British). I am convinced that the reason is that these rifles have no cross-bolting.

 

[Ontario Hunter]

Every Mannlicher-Schönauer in .458 Winchester Magnum that I have ever seen (I own one) has a broken grip (American)/ hand (British). I am convinced that the reason is that these rifles have no cross-bolting.

I suspect the wrist was too thin and no reinforcement rod. The stock for 98 Mauser in above photos was so thin that I had to shorten the rear action screw and add more threads + trim top of mag box before the tangs would draw down flush into their slots. Still had a ways to go in this photo.

Also, note in the image of finished project that I had to significantly reshape the Timney trigger shoe before it would fit inside the trigger guard. That's because this stock made the rifle become significantly thinner than standard 98 Mauser.

I knew that stock wearing a 404J would not last without wrist reinforcement. I seem to recall Mannlicher stocks are noticeably "elegent" (i.e. slim). Look inside. The stocks may have internal crossbolts a la Weatherby. Otherwise I would expect cracking around the mag box where wood is thinnest, not in the wrist.

 

[Nhoro]

Wood splits down the grain. So crossbolts go across wood grain and hold it together to prevent splitting. As others have said, glass bedding also helps. Particularly weak areas like magazine and trigger are worse because more wood is removed so those areas. They arecommonly reinforced with crossbolts. Summary they help, I would also use glass bedding- nothing is foolproof but it all helps.

 

[grand veneur]

All of these measures are of little use for rifles with very strong recoil. Sure, all of these options must be used for such rifles, but ultimately the choice of stock wood is the most important thing. I speak from experience because I can compare the quality of the wood of the stock of my rifle caliber 460 Weatherby Magnum and that of my rifle caliber 500 Schüler. No cracks with the last one, but you have to take the very high quality of the wood of this stock into account.

 

[KJE81]

I got this sketch from the gunsmith that is building my incoming custom rifle in .375 H&H showing the different stock bolts. The forward one is much stronger then the rear one.

This picture below shows the forward stock bolt which is a completly square metal piece inside the wood.

 

[dlmac]

All of these measures are of little use for rifles with very strong recoil. Sure, all of these options must be used for such rifles, but ultimately the choice of stock wood is the most important thing. I speak from experience because I can compare the quality of the wood of the stock of my rifle caliber 460 Weatherby Magnum and that of my rifle caliber 500 Schüler. No cracks with the last one, but you have to take the very high quality of the wood of this stock into account.

I have an inherited Blaser R83 in 8x68 and was told the stock was replaced twice before it stop cracking. I think that it was the quality of wood and grain as nothing else was changed.

 

[odonata]

For a left-handed shooter like me, finding rifles chambered in certain calibers can be a challenge because the factory selections are more limited. So in order to put a 458 Win Mag in my safe, I decided to upsize a 1999 Ruger MkII that was chambered in 7mm Rem Mag mainly as a fun project just to see if I could do it.

I ground down the head of a 4" / 10cm stainless bolt to countersink a hole & install it in the grip for reinforcement since that's what I had lying around the shop.

Some people just epoxy a solid rod of some kind. Basically you want something to keep the smallest part of the grip from cracking under heavy recoil.

I then installed aluminum pillars at the front recoil lug and around the back receiver bolt. I used a chisel to create a small amount of space around the rear tang of the receiver so it would not act as a splitting wedge if it was pushed in a rearward direction. The last step was to put crossbolts behind the front recoil lug and the middle action bolt in front of the trigger. I used epoxy to eliminate spaces that might allow movement of any kind.

An anemic 7mm Rem Mag up top and a more powerful 458 Win Mag below

I then put a 23" 1:14 McGowen #5 profile barrel on it & used chisels, files & sandpaper to enlarge the barrel inlet. So far it's been a really nice rifle to shoot. When you disassemble a rifle down to its basic parts, you realize just how thin the stock is between the crossbolts where the magazine box is located. There's not a lot of strength there so the extra reinforcement to prevent the stock from flexing & the action from moving backwards really helps.

 

[Ontario Hunter]

I opted to drop my wrist rod down through the end of the top tang slot. That is where most wrist cracks originate: top down, not grip cap upward. Most who add wrist reinforcement use 1/4" threaded rod but I elected to use 3/16" straight steel rod (no 3/16" threaded rod available). I scored the rod with Dremel cutting disk to ensure better grip to JB Weld bedding material. I chose the narrower rod because this stock's wrist was so slim. Not a lot of wood to work with.

 

[CBeck]

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.

 

[odonata]

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.

You may be right. I added the rod to my rifle based on the advice of more experienced hunters since I was a newbie with rifles of this power. Basically I was trying to avoid a crack like the one below which another poster said developed from shooting really stout handloads. Were there other mitigating factors? Possibly. Would the rod in my rifle stop that? Unknown at this point. All I know is the extra reinforcement from the base of the grip to the base of the receiver certainly didn’t appear to hurt anything. I was simply trying to be proactive & prevent any cracks from getting started.

 

[Ontario Hunter]

You may be right. I added the rod to my rifle based on the advice of more experienced hunters since I was a newbie with rifles of this power. Basically I was trying to avoid a crack like the one below which another poster said developed from shooting really stout handloads. Were there other mitigating factors? Possibly. Would the rod in my rifle stop that? Unknown at this point. All I know is the extra reinforcement from the base of the grip to the base of the receiver certainly didn’t appear to hurt anything. I was simply trying to be proactive & prevent any cracks from getting started.

View attachment 670136

Note how narrow that stock is through the wrist compared to ahead of trigger guard. Someone trying to make a heavy recoil caliber into a lightweight rifle. Then the shooter pushing the envelope with his reloads. Tsk, tsk.