112 Magnum Target barrel swap

[efm77]

Pardon some of my ignorance. I'm a member to the forum and have done several barrel swaps on my Savages, but haven't been on the forum in quite some time. I kind of have my eye on the 112 Magnum Target in 338 Lapua. But I'm wanting with not only the ability to shoot 338 Lapua but also to swap to a smaller cartridge, most likely a belted mag or similar. I know the receiver, lugs, and lug recesses are beefier and it is heat treated differently to make it stronger. All qualities I like and the reason I'm wanting it. If I've researched correctly, it sounds like I would need to have a bolt head custom made for a different case head. Here's where my lack of knowledge comes in on this particular action. My question is why? I know the lugs on the Lapua are thicker front to back which would make the nose of the bolt come out further in the front receiver ring. Are they dimensionally different otherwise? If I put a regular magnum bolt head on it, can I not just screw the barrel in further until it contacts the go gauge appropriately and tighten down the nut from there? Or is it that big of a difference that there isn't enough threads on the barrel to do so? Any advice/input would be appreciated.

[sharpshooter]

Savage makes the same bolt head for a belted magnum (.532")

[efm77]

Thanks. I knew they did but thought I read somewhere that it wouldn't work in the Lapua action? Maybe I misread? Let me clarify. I knew Savage makes magnum bolt heads. But what I was concerned about was whether or not it would work in the Lapua action. Something I read made me think that there may be something different about maybe the stem length or the thickness of the lugs to where it wouldn't work in the Lapua action.

[sharpshooter]

Savage also made the 110 BA in .300 win mag. Same action, same heavy magnum bolt head dimensions (9/16") lugs. So it would be a drop in replacement.

[efm77]

That's true. Thanks. Do you know where I can get one? Midway and Brownells only show the Lapua bolt head for the BA action. Or would a standard magnum bolt head also work?

[Hotolds442]

If you deviate from the 9/16" bolt lug thickness, your firing pin protrusion will change. If your firing pin is adjustable, you may be able to reset the protrusion. If you have the "new" one-piece firing pin, you cannot adjust the protrusion. So you either build it so that all it takes is the barrel/bolt head swap by using another 9/16 bolt head, barrel/bolt head/firing pin adjustment using another bolt lug thickness, or barrel/bolt swap using a second bolt built for the belted magnum conversion.

[efm77]

Thank you. That's what I was wondering about. Thanks for clarifying. I wasn't thinking about swapping the entire bolt assembly but I guess that might be the simpler thing to do if I can't locate the 110ba bolt head for the 300 win mag. It will be more expensive but won't have to adjust the firing pin every time.

[efm77]

One more question. Not that I want to do this, I'm just curious. Since they're similar case diameters, is this action capable of handling the 378 Weatherby case and its derivatives?

[Hotolds442]

I don't think there's anybody here qualified to rate the Savage actions for their maximum pressure capability. SAAMI pressure specs on the Lapua Mag is 60,916psi, for the 378 Weatherby its 63,817. Those numbers are taken from Wikipedia so their accuracy is worth what you paid for it. Will the action handle 3000 psi more? Maybe. Do you really want to find out the answer is no with the action and all of its shrapnel 3" from your face? I'm just not all that impressed with the Savage platform enough to push its limits. You might be.

[efm77]

Nope. As I said, I was just curious if anyone knew. One thing to think of though is that while it may be 3k psi more, that shouldn't be pushing the limit of the safety margin of the action. And I don't mean a regular Savage action. I'm talking about the one specifically made for the Lapua. Most actions are built with a safety margin close to twice what the cartridge actually produces. Not to say it couldn't still cause lug set back, but should hold together. Again, I'm not one for pushing limits. I was just curious since their cases are similar in size and thought with that being the case that the bolt thrust would be similar.

[yobuck]

Nope. As I said, I was just curious if anyone knew. One thing to think of though is that while it may be 3k psi more, that shouldn't be pushing the limit of the safety margin of the action. And I don't mean a regular Savage action. I'm talking about the one specifically made for the Lapua. Most actions are built with a safety margin close to twice what the cartridge actually produces. Not to say it couldn't still cause lug set back, but should hold together. Again, I'm not one for pushing limits. I was just curious since their cases are similar in size and thought with that being the case that the bolt thrust would be similar.

I think that if a person were to call a few well known gunsmiths who make their living building these type guns,
you probably wont find (any) who would recommend using a Savage action.
I know a guy who has had a 30x378 Wby built on an 98 mauser action for over 40 years.
The only reason he's still alive is he dosent shoot the thing.

[efm77]

I guess it depends on which Mauser. A standard one, yes he's living dangerously. If it's in a magnum Mauser then he should be fine. There used to be a gentleman in here that built 378 size cases on the single shot target actions and never had any trouble that I know of. I believe his call sign was 358 hammer. Not sure if he's still around or not as its been a long time since I've been on here. Nevertheless since savage beefed up the lapua action like that have and the case heads are about the same, I would think it could handle it but was just curious if anyone had done it. The bolt thrust should be about the same. Maybe a little more for the weatherby but it has less case taper so should grip the chamber walls better which helps too. I'm not going to do it because of cost of weatherby brass but the mark v action isn't really any bigger. Maybe just barely. It has the 9 lugs but they're so small, I think the actual bearing surface is minimally more than a two lug bolt.

Anyway, just curious and being somewhat hypothetical. I appreciate the feedback.

[yobuck]

Technichly speaking I guess there all mauser or at least mauser type actions.
And of coarse actions like the FN mauser are a different species than the production
military 98 action. I wouldn't hesitate owning a gun built on one of those either, but
it wouldn't be in one of the large case variety cartridges. I'm of the opinion that the larger
bore cartridges like the 338 and larger don't develop as much chamber pressure as do smaller
diameter cartridges. Notice they don't offer at least to my knowledge, a 30x378 in their lineup.
What happens to the chamber pressure when somebody decides a 7x338 Lapua might be a fun thing to build
on their Savage action?

[sharpshooter]

"What happens to the chamber pressure when somebody decides a 7x338 Lapua might be a fun thing to build
on their Savage action?"

I can tell you first hand what happens, nothing good. Although I had no catastrophic failures because I was smart enough to stop before it got that far, it's a good way to ruin an action.

[efm77]

Don't misunderstand, I'm not condoning over doing on anything or pushing the envelope too much. I'm most likely going to buy this rifle and leave it the chamber it is, or drop down to a smaller case like a RUM size. Just saying I remember 358 Hammer doing it on here with the short, single shot, target actions and a few rounds based off of the 378 case. I just thought that since this action was beefed up for the Lapua, and they're similar in case diameter, that it would be able to handle the 378 Weatherby cases too. And while the larger cases might not develop as much pressure, it's over a larger area so you increase bolt thrust which is kind of what I was getting at. It's not just the psi you have to look at, it's the bolt thrust too. So Sharpshooter, have you tried say a 338x378 in one? Sounds like you tried a 7mm. Jut wondering if you tired a larger caliber and what happened?