How many rounds to crack stock?
 

Big Uncle has me nervous that I shouldn't ignore my gut instincts about adding a second recoil lug on a big bore rifle project.

So my question is this:

If you were worried about a stock cracking due to high recoil - bedded in Devcon steel - how many shots would it take for you to be comfortable that it's not battering your stock?

I'm considering getting a stock, bedding it, trying to break it, then if it breaks, I know I have to add a recoil lug before I get the exhibition stock, if it doesn't, I can be more confident that I won't break it.

I'll be buying and bedding a "fitting stock" to modify and send to the duplicator anyway, so it's not a big issue for expense, just wondering if I put 50, 100, 300, or XXXX number of rounds through THAT stock and the bedding holds, is it ever enough to be confident that the stock and bedding is sufficient?

My motivation, of course, is to eliminate the contact points on the barrel. With the rig I'm planning, one barrel is a high recoil round so it would potentially need another lug, the other barrel would not, and I don't want to have that barrel partially bedded.

Is that caliber one that is sold commercially? If it is get a hold of one and see how the barreled action is fastened to the stock. A reputable manufacturer isn't going to sell a rifle that the stock breaks on after two or three boxes of shells run through it. Just what are you planning on building, a .500 Nitro or something?:biggrin:

I'm guessing you are thinking about doing this project on a Ruger setup and you are worried about that angular recoil lug?

Yup, this is thinking towards my big bore Ruger project. This weekend, I'm going to bed my wife's new 7mm (that will become a 338wm) into a new stock for her to use this winter, and I was thinking more and more about the .458wm that I'll be building to go along with it. Sarah's rifle will probably be getting a .416Ruger barrel as well, as I really like the round so far, so that's a new addition - a 5th cartridge, and one that doesn't share a common case (Ruger says it shares a common follower and mag box, and of course, the same mag bolt face).

I'm not concerned about the angular lug, actually very confident in that design, but a little concerned that it'll be able to crush the wood around it. Every big bore I've owned had 2 lugs, but even then, if they weren't properly bedded, they'd break the stock. If they WERE properly bedded, I had nary an issue.

To Oldtimr's point about pulling a stock on an existing model, well, that's pretty simple - there's no such thing as a 458win mag Ruger M77 Hawkeye. The most powerful cartridge for which the Hawkeyes can be had is the .416 Ruger - which is about equal for ENGERY, but about 10-15% behind the 458wm in recoil momentum. I had a Ruger RSM in the past that DID have the "new version" of the forward recoil lug, but it cracked its stock behind the tang anyway. I bedded it into a replacement stock from Ruger, and it survived as long as I owned it after that without breaking, but that wasn't many shots (.458 Lott).

I've talked to a handful of big bore smiths that have agreed - if you bed the Ruger action properly, it action won't need a 2nd recoil lug. But I really don't care to crush a $1500 piece of wood either.

My discontent is coming from rumors - I bought a Ruger Hawkeye Guide Gun in .416Rug to act as a bench mark for these custom rifles, mine is from the early production, and does not have any recoil lug on the barrel, just the one on the action. I'm told, however, that "some people think" Ruger started putting them on the newer production models of the .416R African and Guide Gun, and that the Alaskan was discontinued because it was crushing the synthetic stocks (I don't buy that). However, I have yet to confirm anyone that owns a .416Ruger Guide Gun that HAS a 2nd lug, and Ruger customer service confirms that they do not (but they're not always aware of most recent product changes, especially on low volume models).

So I figure, why not test it out myself? If I can bed the rifle into a weaker stock, fire XX number of rounds without failure, then do the same bedding into a tougher/denser wood stock, pretty fair to assume it won't fail.

But what's that number? I'm thinking over 100rnds, not sure if I think a stock would crack after 300rnds if it didn't before (and if I ever fire 500rnds out of it, I'll be the one that's cracked!)

Well, your concerns are certainly well founded. Having fired several rifles of that "magnitude" and owning more than a few, they certainly are hard on a stock. Not to mention the shoulder behind that stock. If you were thinking about a laminated stock then your concerns would be a little less needed. But if you are going after a custom walnut then I personally would think quite seriously about adding another lug to "spread" that energy around so to speak. As far as your testing procedure, I would imagine 100 rounds should be plenty sufficient to show signs of stress. Granted anymore I surely wouldn't want to be the one doing the testing. My poor old shoulder just can't handle recoil like it used to. My .500NE will "straighten your hair" and it's getting to where I just can't handle full power heavy bullet loads from her anymore.

Shoot it from a gun vise, that will be the true test !

Yeah but not a realistic one. Stocks are designed with the shock absorption of the shoulder in mind. I've seen several stocks cracked from people using lead sleds and such devises.

I thought the object was to test the strength of the design !?!?:fighting0007:

I'm pretty sure Mercy would prefer a realistic test. He is an engineer ya know :D Granted using a vise or a lead sled would be torture but probably a bit beyond what he would want for reality. Though his shoulder would be thankful for the use of one :D

I don't have a lead sled myself, but my brother-in-law does. I've never seen a benefit from one, so I only had one for a short time...

BUT... Loaded with a couple hundred pounds of sand, it'd sure be a good stress test for a stock. I even still have a couple remote firing devices from my R&D days. Definitely more pressure than 200lbs of me behind it would have. BUT... definitely more likely to crush a stock, which might not be representative of what 200lbs of me would do.

I can usually get through 20-30rnds of 458wm before I give up, plus my wife is generally more recoil tolerant (or at least rolls better with heavy recoil) than I am, so she'll be able to stack up some rounds too.

I'll be bedding with a healthy layer of Devcon Steel (considering Titanium), and considering adding a solid steel block to the stock behind the recoil lug, supported screws and bedding. Kicking back and forth using steel tubing instead of the aluminum pillars that I have as well, at least for the front pillar. I've ran that idea by a couple smiths that are versed in building/rebuilding big bores, and they've all agreed that a good thick layer epoxy bedding job would be sufficient, let alone my plan(s), citing that factory rifles with extra lugs are designed to survive firing without bedding at all - just raw stock, which are generally poorly fit, so bedding offers more action support than it had from factory.

Hopefully I'm worried about nothing, but since the only down-side is having a pressure/contact point on my 300wm barrel, instead of fully free floating, otherwise I'd just dovetail a lug into the forend, drop a block of steel behind it in the wood, and be done with it.

Honestly Mercy I believe the Aluminum pillars with a healthy epox bedding would be sufficient. You never said whether you were going Lam or Natural with the stock. If going with a Nat I would go with the extra lug with the epox and alum pillar. If Lam just the epox and alum pillar. Plus your other plans too for the variability purposes of switching barrels and such. When you get the beast done yell and if I'm mobile by then I'll swing out and bring the Krieghoff double out as well as the new .338 you helped me figure out and we can play a bit. I'll load up some express specials for the Krieghoff just for you :D May load up some yote smackers for the 7mm08 and bring her out to and go smack a few yotes :D

For the short term, my wife's rifle is getting bedded into a "coyote" laminate Prairie Hunter from Boyd's. She decided she wanted me to screw the factory barrel back on so she can use it for deer this winter.

We have a couple of cheap american walnut blanks from Richard's Microfit (got them $68 a piece, shipped) to serve as fitting stocks to send out to Macon to get custom Turkish walnut stocks duplicated. Still waiting for Macon to call me to let me know they've found two suitable blanks that are well matched for our rifles - kinda hoping that call doesn't come too soon, since that signals a hefty bill...

I wouldn't mind getting a purple Prairie Hunter for mine, or black/grey, possibly to have it as a "hunting stock" for beating around the deer woods, but my wife says that if we're spending money for "fancy stocks" then by God, we're going to get our money's worth out of them. She insists that if we're afraid to hunt with them, we shouldn't be bolting them to our rifles.

I hold the same view as her. I have a few rifles that people get flat out flustered when they see me pull them out of the case for a hunt. I usually get a "you taking THAT thing out to hunt?" Of course I do tend to "baby" the purdy ones a little more.

So, your going with matched grain walnut blanks (and it is hard to beat that Turkish for some pretty wood) then I would definitely go with adding a lug. It's good hard wood yet still has some flex to absorb punishing recoil (many of your finer express doubles have it) but with the serious expense of that particular blank and having it worked I personally would do everything I could think of to make sure it lasts a LONG LONG time. And it's not like it's a hard thing to do nor very expensive as you have the abilities to do it yourself so why not just take that extra precaution and worry yourself less?

I would think the recoil would be easier on a stock compared to a 338 Win Mag shooting a 250 gr bullet? I've never shot a .458 but I would imagine it's more of a big push then a sharp job and the latter I would think is a stock killer??? I could be completely off base and talking out of my butt too...lol

According to the load of course Jeepkid but a .458wm has more crack that you would think. You would imagine a .500ne to be more of a "push" as well but them buggers have the crack AND the shove. A .458wm has pretty much the same results as well. Again, all according to the load setup as well as the stock design (felt recoil) and weight of the overall rifle. I would imagine Mercy will be loading his up for optimum results from that particular cartridge.

You could bed the front lug with enough clearance that the barrel itself would have no contact with the bedding. Tape the barrel well and let only the lug sink into the bedding compound. If your other barrel is a different shape you might have enough clearance anyhow to avoid a pressure point.

If you use a single lug it will probably be fine with good bedding but to take the chance of ruining a trip (along with the stock) due to a split would be too much risk for me.

To address the original question - I have split stocks more than once with 50 rounds or less. The wood will continue to shrink a little with age and recoil compression so it could happen much later but I have seen most problems occur at the beginning.

Have you figured out what you are going to do with the new stock yet?

I'm gonna go for it without an additional lug in the test stock.

The 7mm, 300, 338, and 416Rug exists in multiple models without an additional lug, so I'm deferring to that experience for those barrels, so the only odd man out was going to be the 458WM. With a hefty bed of Devcon Steel behind the recoil lug, dual cross bolts, and a relieved tang, I'm going to give it a shot for about 100-200rnds of 458wm with the pattern stock - Circ Walnut, weaker than the Turk Walnut I'll have for the permanent stock.

If it does break, I'll add a dovetailed lug to the barrel, and as you mentioned Uncle, I'll shape/step the lug and relieve the "anchor" within the stock such that it can't touch the other barrels. If it doesn't, then I'll take the 100-200rnds as confirmation that it'll survive.

Of course, the whole thing's kinda on hold right now, spending my limited free time in the deer stand instead of the workshop!

That sounds like a reasonable approach. If the stock (and you) are still in good shape after that many rounds you should have a winner. Please post a picture of your rifle when you get it nailed together.

Seemed reasonable to me too, given the information I have and the limited logical reasoning capacity I possess - but that doesn't mean it's the "right answer"!!

Hopefully it doesn't land me in hot water with a very expensive stock playing the role of useless paperweight, ruining a very expensive hunting trip. Stuff happens, and usually at the least opportune times, so I could find myself in a position where I built the rifle out of titanium tempered with dragon tears, but then drop it off of the side and the safari jeep drives over the top of it and bends the barrel... Just gotta mitigate as much risk as I can.

It'll probably be spring before I start tearing into these again - I'm sending them both out together, and my wife wants to use her 7mm for deer and coyotes this winter, which is nice, because that gives me time to save up for the scopes and practice my checkering.