[Diego Naveira]

Hi buddies, I´m new in this forum and this is my first post.
I own a Mark II 77 RSI International (Manl¡cher style) 30-06 carbine. Last weekend I was testing it in order to go hunting and noticed that a handload that previously grouped 1/4 MOA with a slight vertical spread, opened up to a 2 MOA with a WIDE horizontal spread. I returned home quite mad and dissambled it and noticed that the piece of wood between the magazine and the trigger (it´s the part of the stock that runs along the middle screw) was cracked all it´s length by the very middle in the same line of the barrell/stock. This hair thick crack produces a slight, almost unnoticeable, movement when pressed with the hand.

Questions:
How could this crack happen?
Can this crack affect accuracy? I mean, the action is firmly attached to the stock by the other two screws (front and rear) in places with no cracks.
How can this crack be fixed?
How can I prevent happening again once fixed?

Extra info:
This rifle is pillar bedded anb barrel/action floated.
The rifle was adjusted to the stock according the instructios: front screw very tight, rear screw tight, middle screw barely tight.
The handload I was firing is 55.5 grains of RL19 behind a 180 grains Sierra bullet with rifle magnum primer (to burn all the powder in that short barrell). Quite mild as you can see.

I´ll be glad to hear your opinion, sugestions and such.

Thanks a lot

 

[twodog max]

Just a shot in the dark but I am thinking one of two things happened. First there was a wood defect that just now has finally shown up or when the pillar bedding/free floating was done something created some pressure at the wrong spot and caused the crack. I think the last thing would be shooting the rifle with the mentioned load. It can likely be repaired and should be before it gets any worse.

 

[Varminterror]

There are 3 places that Ruger stocks crack, 1) behind the tang, 2) behind the recoil lug, and 3) in the trigger bridge, aka, where yours broke. These are the places that stocks take the most impact from the action under recoil, or take the most flexion.

Pillar blocking doesn't help support the action under recoil. You did not mention whether it was epoxy bedded, or just pillar blocked. If it was NOT bedded, then the recoil lug is able to compress the stock over time, and wooden stocks naturally shrink over time anyway, which can put stress on the stock in new places.

If the magazine box and the forward trigger guard screw were not properly relieved into the stock, this can put pressure over the trigger bridge also.

Cracking in the trigger bridge was a driving force behind Ruger adding a second cross bolt to their Hawkeye African and Guide Gun stocks.

Which direction is the crack passing through the stock? Parallel or perpendicular to the front trigger guard bolt? Running fore and aft, or vertical through the stock?

Usually, they crack longitudinally (running lengthwise of the stock) through the thin trigger bridge. To fix such a break, you can either have Ruger replace your stock (which they may not do since you had it blocked), buy one from an aftermarket supplier, or have a stockmaker add a crossbolt to the trigger bridge. They'll drill a hole through the stock sideways, pull the stock crack open as far as possible, shoot some glue into the crack, then tighten a crossbolt coated in epoxy in the drilled hole to pull the stock back together. You can either leave the bolt heads exposed - typical Ruger style - or have them hidden under ebony plugs.

 

[Diego Naveira]

Thanks a lot buddies. I´ll take the carbine to my gunsmith to fix it´s stock with the mentioned crossbolt solution as the trigger bridge is cracked longitudinally. Guess he´ll mend it propperly. I´ve a question regarding the material the crossbolt should be made out of. Steel? wood? polymer?

 

[weaselfire]

The cross bolt is a steel bolt. It can be done with hardwoods but its nowhere near as good since you can't tighten it as easily. Ruger normally exposes the bolt as in their guide guns, but a plug covering it is an option. Usually the plug is ebony so it stands out, it's almost impossible to blend a plug so it's hidden.

Jeff

 

[Varminterror]

Thanks a lot buddies. I´ll take the carbine to my gunsmith to fix it´s stock with the mentioned crossbolt solution as the trigger bridge is cracked longitudinally. Guess he´ll mend it propperly. I´ve a question regarding the material the crossbolt should be made out of. Steel? wood? polymer?

Cross bolts are called "bolts" because that's what they are - bolts. I described the process and components in my last reply.

Ruger traditionally uses exposed two piece crossbolts, as such you see a bolt head on one side and the end of the bolt and the splined nut on the other side. Talley offers a 3 piece bolt assembly, consisting of two bolts and a coupling nut in the middle, such that you can either see two similar bolt heads at both ends, or symmetrically cover them with the same escutcheons and plugs. Mosaic pins can be used as well, if they are roughed for grip, and the stock maker must compress the stock laterally during the drying and curing process. Engraved crossbolts heads can also be used.

If you don't want to have any impact on the external appearance of the stock, a weatherby style reinforcing stirrup can be used. This is a U shaped (square corners) embedded into the trigger bridge through the action inlet, such that the reinforcing support is not visible from the outside. This is the most expensive option, and most complicated repair. Whether hardened steel or spring steel should be used is a topic of debate, but either way, the smith has to form and re-temper the steel, then route a precision inlet into the bridge to install the support. It's visibly no impact, but the work that went on behind the scenes is the most intense.

 

[Diego Naveira]

Thanks again buddies. Let´s proceed with the crossbolt then.

 

[BassMan]

Two cross bolts, go for another one in back of the recoil lug.

Not wanting to spend much I simply drilled a hole through the stock, coated the right sized machine bolt with epoxy, threaded the bolt in and then cut and filed off the excess on both sides. To finish the job I ground into the bolt using a small diamond ball Dremel bit and filled the hole with epoxy that was then sanded smooth.

Nice fancy cross bolts with attractive heads can be used, one head acting as a nut that can be turned.

Your gun smith will know about all this.