M1924 Sporter - cracking at tang

[Gregory Gauvin]

My uncle recently discovered a M1924 Mauser in his father's attic. It had been sitting up there for 25+ years. He gave it to me to go through it, clean it up...etc. It's amazing in pristine condition. All matching ( sadly somebody took a very nice M1924 and sporterized it - i.e., bent and swept bolt, jeweled it, took off military sights and dropped it into a wood sporter stock and fitted with lyman 57 SME sights. The stock had a few dings and blems. I went through the rifle thoroughly. The rifle was not re-chambered - the original 8x57 barrel was the best looking 8mm barrel I have ever saw - no pitting, no wear...in fact, I do not believe the rifle had been fired, ever. I steamed out the dents, re-blued some of the metal, gave the stock a beautiful hand oil finish. I spent a month turning the rifle into a piece of art. I checked headspace, fitting a safety (which was missing), got a .040" lyman peep aperture for it (also missing) to work with the 1/16th target sized gold front sight bead. I polished the feed ramp, and bolt (leaving the jeweling on the body), polished cocking sleeve, trigger contact points and pins...etc I can go on.

There was a small, near invisible hairline crack near the tang area of the stock. It was not deep, nor did it extend to the tang screw. Front recoil lug showed no signs of cracking or stress. My main concern was that this rifle, in 8x57, fitting in a light weight sporter stock would not hold up to recoil. Needless, I used thin cyanoacrylate to penetrate that small hairline crack. I was hoping the stock cracked here from stresses of temperature and humidity extremes being stuck up in an attic with no central air.




http://postimg.org/image/f46xhd3a5/

I had warned my uncle...that 8x57 is a pretty potent caliber. Needless to say, range day arrived. I had bore sighted the rifle and was on paper. A few clicks to dial in windage and after bore had fouled out (around 10-15 rounds - I had cleaned barrel down to bare metal, not that it was copper fouled to begin with) produced groups I had never seen before in any 8mm chambered rifle. I was firing 63 year old surplus ammo, and producing 3 shot groups smaller than a quarter. Unfortunately, my fears became reality. Firing stopped at 25rds. The crack at the tang area of the stock had begun to open up, elongated and then turned 90 degrees down against the grain.

I am going to having my former woodshop teacher and gun collector take a look. He has repaired 1903s with tang stock cracks - however, they were not fired again. I would like to have this rifle be able to be fired and withstand recoil forces, and not just sit around and be pretty. I know there are several methods of repair.

I don't know what my Uncle would want to invest into this project, but me, personally, I would scrap the wood stock and go with a pillar bedded laminate stock and glass bed it. As far as repairing the current stock...besides cosmetically fixing the crack, what method would can render this rifle from further abuse? Sleeve the tang screw? Pillar bed? Glass bedding?

Trigger is great, rifling is sharp, it's like a NIB rifle. I didn't expect it to clover leaf groups with old surplus. With handloads, this rifle will be one heck of a shooter. If I glass bed the stock, even more so. But glass bedding alone won't stop that stock from splitting into 2 or more pieces. How should I proceed?

[Mobuck]

"But glass bedding alone won't stop that stock from splitting into 2 or more pieces. How should I proceed?"

At this point, you may need profession help. I don't see why a good bedding job and a solid fix of the recoil lug won't fix the problem. If the split is separating, a repair using a metal reinforcement may be required.

[hooligan1]

If you can't confidently pin the recoil lug, and drill a stress relief hole at the end of the cracks and fill with epoxy, then let a competent Smith do the job.
Those actions are nice btw, and if it were mine, I'd fix the stock or have it done then enjoy shooting that dude...

[tangolima]

Two things can possibly cause split in tang. The tang of the receiver is making contact with the wood, so that part of the recoil force is driving the metal into the wood like a chisel. The cross bolt is not compressing the wood behind the recoil lug tight enough, so that the wood bows outwards under recoil.

It is important to properly relieve the wood in the tang area to ensure the recoil lug and the wood behind it being the only recoil bearing surface. Better yet the front of the magazine box can be bedded against the wood behind the cross bolt to provide added support.

With all that done, the tang wood can be further enforced by adding cross members. In the old days it was splines inletted across the grains. Easier is to drill a small hole across and put a brass rod through, glued in place with epoxy.

That's how I fixed an old Hanyang with awful splits.

-TL

[James K]

That is a very ordinary 1950's vintage mass-produced sporter stock. If you really like the rifle, you might consider not spending time or money on that stock and have a better one fitted and bedded properly.

Jim

[kilimanjaro]

Putting a synthetic stock on this beauty would be a crime. Get if fixed properly or get a new stock, you can still find them.

[Jim Watson]

I think the Tango approach would be worth trying.

If the rifle shoots accurately in that stock (while it is in one piece) it seems worth fixing. Brownells sells long headless repair screws to hold a crack together.
http://www.brownells.com/gunsmith-to...t-prod617.aspx
We can only hope another layer of glue will stick.

As he says, there must be clearance behind the tang or it will just wedge the crack back apart no matter what you do.

Sleeve the tang screw?

Mauser sleeved the tang screw 90 years ago.
A lot of those little sleeves got left out in the sporterizing process which does not do the stock any good. I would round one up. It might mean rebedding but you will probably have to do it after fixing the split anyhow.

[4V50 Gary]

I'd make sure that the backside of the recoil lug is properly inletted. It must bear against the wood. If it doesn't, someplace else will absorb the recoil and I suspect that is why the tang broke. After the lug is inletted (probably a bit of AcraGlass to fill any gap), then I'd glue that piece of tang back into place.

[Gregory Gauvin]

TANG:

You were correct. Upon close examination, the tang of the receiver is making contact with the wood. I'm going to cut a relief there. I also noted that the rear tang hole itself is sleeved. This stock has no crossbolt reinforcement.

Aside from repairing the more or less "cosmetic" crack (as the crack is not deep no does it extend towards the rear tang screw), making a relief so the metal of rear tang does not contact the wood, I'm thinking of glass bedding the recoil lug area.

Anything else?

[Gregory Gauvin]

Here is a picture of the crack forming:



Can anyone tell me what this black stuff is? Doesn't look like modern glass bedding to me. Some type of early 1950s bedding or somebody just spray in on some type of tar or something? For purpose...to seal wood? I'm clueless on this one.



Rifle was originally had a shellac finish, possibly an oil based shellac. Which was dinged, uneven and terrible. I removed the shellac, as I steamed out most of the dents and dings..etc...the picture above is my month long hand rubbed oil finish job. Most guys do fast true oil, varnish or quick finish jobs and make a stock look shiny and nice...I'm more traditional and say slow and steady wins the race. And an oil finish is so much more easily repairable. The day I refinish a gun with a glass mirror polyurethane or such is the day it gets dinged.

[Gregory Gauvin]

I apologize for the clarity of the photo of the crack. It is minor and difficult to see, but starts with the grain at the tang and takes a 90 degree turn to the right, against the grain.

I've been working on guns for years, and hung with gunsmiths and circles with life long experience since I began shooting 20+ years ago. I can confidently do much of whatever, it isn't about how much cost. This isn't my rifle... Only a factor of time, and how much my uncle wants to invest. I told him if it shot this good with 63 year old surplus in this, a glass bedded synthetic or laminate stock would increase accuracy. I could tune the trigger a bit more, although trigger is fantastic now as is with the little work I did. My uncle isn't a hunter...so, a 3-4lbs trigger for target work would be great. I would guess its around 5lbs now...no creep. Also suggested drill/tapping for scope mount, ditch the Lymans, and put on a SWFA SS scope. But for now, would like to have this rifle shoot with this stock.

As my uncle is in love with the cosmetics of the wood as well.

[tangolima]

Originally Posted by Gregory Gauvin

TANG:

You were correct. Upon close examination, the tang of the receiver is making contact with the wood. I'm going to cut a relief there. I also noted that the rear tang hole itself is sleeved. This stock has no crossbolt reinforcement.

Aside from repairing the more or less "cosmetic" crack (as the crack is not deep no does it extend towards the rear tang screw), making a relief so the metal of rear tang does not contact the wood, I'm thinking of glass bedding the recoil lug area.

Anything else?

Looks like your rifle doesn't have a cross bolt, like a k98k does. The recoil lug rests on the wood in front of the magazine, similar to a Remington 700. Can't make it out in the first picture, there is most likely some sort of cross member reinforcement through that piece of wood, something like a copper rod. If it really has nothing, I would surely add one there.

This is important. Under recoil the wood will bow outwards around the magazine. Without cross member reinforcement, it will split in the tang. Buy a run of brass rod from hobby shop and drill a matching hole through that piece of wood. File a few shallow anchor notches on the brass rod, and implant it though the hole with epoxy. Dress up the ends of the rod and it will look nice with the wood.

Glass bedding will most likely improve things. But since the rifle is already shoots well, I will wait and see whether that is necessary.

-TL

[Gregory Gauvin]

Thanks. For this caliber...what diameter rod would you suggest to reinforce the recoil lug area? Also...I am familiar with crossbolts, but for this particular application, should I install the crossbolt directly in the center of the recoil lug area or should it be further forward or towards the magazine well? I am assuming directly in the center...not much material to work with.

Also, that black stuff...I've been looking closing. It appears to be bedding material. The rifle has barely been shot...and the action fits the stock snugly. Don't know why the bedding material extends all the way up the forearm of the stock...usually 3-4" past the recoil lug area to keep the barrel free floated.

As far as epoxy goes...I know a slow curing, high strength epoxy is best. How would JB Weld hold up?

[HiBC]

Think in terms of recoil being energy flowing into the stock.And think of the mechanics/grain structure of wood.
The primary transfer point is the wood behind the recoil lug.As it is bedded,that should be 100%.

Now lets look all the way back at the tang,where your crack is.Due to the curvature of the wrist,the wood falls down and away behind the tang.That wood is unsupported to the rear.It will chip/split/flake off like kindling.Standard practice is some clearance behind the tang.
That's good,but more goes on during recoil.

Lets go forward again.The mortise through the stock for the receiver/mag/and guard.Its open.You have two thin slabs of wood,connected by a web of wood behind the recoil lug,and another web of wood between the mag mortise and the trigger mortise.

During recoil,the side slabs want to bow outward.
This bowing outward force wants to split the stock.Behind the recoil lug,between the trigger and mag wells,and at the tang,where your crack is.

As a special bonus to this splitting force,tapered sides going back to the tang,like a wedge.

So,make sure that wedge is not real tight.

Then,do this.You can do it in stages,step at a time.That web of wood,between the mag box and recoil lug.Use releaseagent on the mag box,but bed that wood to be backed up by the mag box.Then bed the rear of the box and the lower tang to transmit recoil into the stock.Note how well all that wood is self supporting.Once the linear recoil force is transferred to the wood behind the recoil lug,you want it to go into the front face of the mag box,then to the rear of the mag box and lower tang.The wood behind these surfaces is strong and supported.
The mag box/guard assembly is critical structure to absorbing recoil.

And then,yes,by one of several methods,a cross pin or bolt through the wood behind the recoil lug,and just ahead of the trigger assembly will limit the outward bowing.Look at a military stock.They have them.
I know its expensive,etc.I find Brownell's Accra-Glas gel easy to work with and reliable,for jobs where you do not want the material to run.Its a little stickier/stringier than peanut butter,but similar.

Regular AccraGlas or West SystemEpoxy have both worked well for me.
Honey/motor oil viscosity.Good for liquid gluing.

[tangolima]

I used 3/32" brass rod for my Hanyang.

As for epoxy glue, they all work similarly. I like slow cure as it gives me more work time. The key is not really the glue, as the glue is actually stronger than the wood, but the surface preparation.

All surfaces must be free of oil and dust. They need to have roughness for the glue to anchor on. Anchor holes can even be drilled into the wood to mechanically lock the cured glue on. That's also why to file shallow notches on the brass rod for the glue to "bite" into.

Depending on situation clamping may benefit. Lastly the glue needs to be given enough time to properly cure. It also requires thorough mixing the glue before application. Mix it till you think is more than enough, and then mix it more.

-TL

[tobnpr]

I was hoping the stock cracked here from stresses of temperature and humidity extremes being stuck up in an attic with no central air.

Could be, but not likely.
Cracks at the tang are caused by the back or sides of the tang contacting the surrounding wood. No go...

Even with the recoil block in place there will be movement, and there needs to be space for the metal to move under recoil. It's simple physics, violent recoil- back edge of the tang slams into the wood.

Once the action is bedded there will be no further issues, as the action will no longer move in the stock and the recoil forces will be mol evenly distributed from the wrist back through the buttstock. Still, I would leave a small (couple of hundredths ) gap around the tang, enough to eliminate contact and not create an unsightly gap.

[Scorch]

Your rifle needs to be glass bedded to keep the tang and tang screw from tring to split the stock every time you fire. You should have .015" or so of clearance at the back of the tang and all radiused areas at the rear of the action..

[Unclenick]

The black material is some form of hard pitch, probably heated and poured or painted in. They didn't have epoxies widely available in the 1950's. It might be worth cutting that old resin out and doing some glass bedding. It may also dissolve in mineral spirits if it is pitch. You'd have to try it to see, but be prepared it can then stain and color the wood.

Speaking of epoxies, you might consider painting in some Rot Fix or other water-thin epoxy for repairing rotted wood around the inside of the inletting so it can creep into the wood and reinforce the wood fibers. Do this just before bedding so the thin epoxy has not quite completely set when you apply the bedding. That way the two can bond together better.

[Gregory Gauvin]

Thank you all...great suggestions. The black pitch, or tar, is unaffected being rubbed with mineral spirits. I had thought the mag box fit was tight to the wood at both ends, but indeed, I just checked and was able to slide the largest width of my feeler gauge set between the box and the wood - I didn't even take note of what the feeler gauge size was. So indeed, it needs to be bedded, particularly at the areas all mentioned.

I'm planning to use brass rod for cross bolts as opposed to buying expensive manufactured cross bolt pins. When I glue them in...how do I keep enough epoxy in the hole...as won't pushing the rod through push out most of the glue?

[HiBC]

The pin will push epoxy out of the hole,but if you coat the pin with epoxy,too,it will be a good job.
There are a lot of ways to cross pin or bolt a stock for re-enforcement.Some are better than others.The "expensive type" or other means that have some head and some screw compression,they resist the splitting ,bowing out forces better.But a simple pin will probably help.A drill motor used like a lathe will let you file grooves around the pin for the epoxy to bite.
You may use brass if you wish,I'm not sure I understand the advantage over drill rod or even a nail.The ends of the steel pin can be cold blued and its a little stronger than brass.
Don't forget release agent on the mag box.
And avoid pulling it out by the trigger guard.

[tangolima]

Brass doesn't rust, and it looks good with wood.

I myself don't like using drill rod in guns. It is same sort of steel as in drill bits. Hard but tends to be brittle. It doesn't take shock loads well. It is just my choice. I prefer spring stock if I need to used steel.

I wouldn't worry about the rod pushing out all the epoxy. The glue does need to be a lot, but just enough to fill all the voids.

-TL

[Gregory Gauvin]

I'm more than likely going to bed this with MarineTex, or PC-7. Not that agraglas is expensive...it's just I have Marine Tex, Devcon, PC-7, PC-11, even Splash Zone on hand. No reason to go buy stuff when I have materials on hand that others have successfully used.

As far as a release agent, or parting agent, I was thinking either vaseline, or Kiwi shoe polish...I hope I don't have a problem. Unless anyone here has used any of these epoxies and can suggest a better parting agent.

Lastly...The angles on the trigger (sear) and cocking sleeve are sharp, clean...I polished them to mirror. The trigger is actually...surprisingly...better than I thought would be using military parts. There is absolutely no creep. I would estimate trigger break at 4.5 LBS. This is not going to be a hunting gun. It's going to be a target rifle. I would like to bring the pull down two 4LBS, 3.5 would be ideal, or if I guesstimate is off, and rather 5lbs, a 4lbs would suffice. Just a teenie bit lighter would really be the cherry on the pie after all this work.

Two questions: I'm not going to buy 8mm snap caps that I'll use this one time and never need them again. I'm not going to make 20+ deprimed cases and do a hot glue deal. Is there any method I'm not thinking of to dry fire this rifle to measure trigger pull? I will need to dry fire it at least 20 times.

Secondly...The trigger spring, or sear spring, or trigger return spring no matter what you call it...is over power. It's got plenty of power that even taking 2 coils off wouldn't even put it in a dangerous trigger no return/reset condition. But I would only consider clipping a 1/2 coil, 1 coil at most. I also know the firing pin spring adds to the trigger pull weight. I'm not inclined to clip coils on the firing pin spring, as some of them military rounds need that hard hitting pin strike to light off those thick cup primers. But I don't think 1 coil would put me into light primer strike territory. What really effects the trigger break more...the firing pin spring or the trigger/sear spring?

All my rifles are collector grade guns, unadulterated in military configuration. This is rather my first in depth work over on a custom sporter mauser. Give me a 1911 or a M1A or FAL or AR or heck even a Winchester 290....and I could work them over blindfolded.

[tangolima]

Not familiar with the epoxy products that are in your "inventory". Bedding compounds should have minimum shrinkage as it cures. Even the famous agraglas is only marginal I read. The best compound I have used is devcon steel putty.

Shoe polish is fine as release agent. But watch out for mechanical locks. If you allow that happens, no release agent in the whole wide world would save you. Preparation is the king. You may just have one chance to do it right.

4.5lb 2-stage trigger is already excellent. It is the delta between the stages that is important, not really the absolute weight. The rifle is already shooting superb before bedding. I wonder why the pursuit of perfecter than perfect. If you must, a over-travel limiter is probably a better use of efforts.

Snap caps for a mouser is moot.

-TL

[Dixie Gunsmithing]

What I use for pins is all thread, or just cut the head off a small screw. The threads hold the epoxy. I keep all thread, because I can cut it to the length I want. You can make pins, as mentioned, or by stock repair pins, that are grooved.

[HiBC]

A couple more possibilities,just to kick off some creative thinking.There are a LOT of approaches that are fine.

You could drill a small pilot hole through,and make a shallow countersink or counterbore,not much,on each side.Cut your all thread,or whatever you use,slightly short..Mix your epoxy with the black dye they supply in Accra-glas.
Fill above flush and dress it off.You will have a black dot on each side.

A slightly more "rustic" but acceptable(to me) approach,use something with a head,similar in geometry to a nail.Make or find a small washer that will just slip over the pin.Drill,and once again make shallow counterbores.
Install with epoxy,set the washer over the pin,and peen the end of the pin.
IMO,done well,and cold blued,it could look fine. And its the IMO that counts.
I'm not ruled by my critics.
I have heard of taking a very sharp chisel,and curling up a shaving,leaving it attached,at the site of the pin.After the pin is installed,the shaving is glued back down as a veneer.I lack confidence in pulling it off,myself.


Tangolima:Please do it your way!!With my respect.We are entitled tour preferences.

FWIW,(not an argument) Some would say if the rifle is Walnut and blue steel,the ends of such a pin might look better following suite as blue steel.
But that is pure preference/opinion.Your way is fine.

In my experience,drill rod is usually sold in both hardened and unhardened conditions.It may be W-1 or O-1 tool steel,and sometimes is available in other alloys.
The advantage to drill rod is it comes OD ground to size.
As it comes,I have not used the W-1 much..I have used the O-1 extensively.Frankly,its not my favorite steel.My attempts to eyeball torch harden and draw parts HAS disappointed me with brittleness on more than one occasion..
With pro heat treating,its a lot better,which says my heat treating is poor.
And,like any oil hardening,it warps in quench

But,as purchased,soft or hard,I think it would hold up to the task of being a pin.

Now,if you need to make a gun part out of something "good"look up "Mold Core Pin" DME might be a supplier.
They are heat treated,od ground,and made of H-13.They come in two hardnesses.CS,and CX.I forget the Rockwells,but the CS will cut with high speed,and the CX willcut with carbide.
For really hard/tough,mold ejector pins are not only ground and polished,they are nitrided toover Rockwell 50C,maybe near 60.

Core pins and ejector pins come with heads,that are usually annealed.
A couple decades of moldmaking ....