375 Scovill or 375 Whelen

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Canuck65

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So I've got the itch to build something out of the assorted M98 bits and pieces I have lying around. I think I've narrowed it down to these 2 choices. The action I want to use is an old FN98. I've got 3 or 4 Husqvarna M98 30-06 barrels in decent shape as well. I suppose I could just do a boring old 35 Whelen, 9.3x62, 338-06 or whatever, but I'd like to take my time and make something more interesting I think. If I was to go with a more common chambering, I'd likely just buy a rifle ready to go.

Anyone have experience with either of these cartridges? Pros and cons of each? I've seen dies for these, but what are the odds of finding reamers to cut the chamber?
 
I have a 9.3x57 and a 9.3x62; also is several 30-06 here. Those barrels not going to do you any good - you will need a barrel with 9.3 mm groove size, or .375 groove size to make those wildcats - 30-06 barrels will need to be reamed to larger bore, then re-rifled, then re-chambered.

As per article by John Barsness - a "Scovill" wildcat - based on 9.3x62 - is going to pretty much maximize case volume for 30-06 size head and still give you a usable shoulder. I think much more is probably possible with rebated rim design (30-06 / 9.3x62 rim with larger diameter case body).

FYI - is no small thing to convert a military Mauser 98 to a hunting rifle action - remove stripper clip guide, drill and tap for scope bases - alter bolt handle for scope clearance, replace the military safety and often replace the bolt shroud, often want a hinged floor plate (or a detachable magazine set-up) , then "magic" polish / grinding to feed rails on underside of action to get the cartridge of choice to feed slickly, polish down the action and re-blue - install and headspace the barrel. "Modern" people probably want a "trigger blocking" safety, instead of a horizontal swing three step safety. Has been done a gazillion times over the years, but does not make it an "easy" thing to do. There were MANY FN 98's made over the years - the last run was chambered in 30-06 for the Belgian Navy and their Army - might be the "best" ones to start from? There were also commercial variants made by FN of the 98 action - Husqvarna used a lot of them - a great amount of the conversion "work" was done at the factory.

Or maybe consider a 308 Norma Magnum - was designed from the "get go" to be done into surplus 30-06 chambers - uses same barrel / bore as 30-06, but needs reamed chamber and altered bolt face / extractor. Was commonly done in USA to P17 Enfield's, 1903 Springfields - not certain why it could not be done on a 30-06 Mauser 98.
 
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Have a 375 Scovill-Hawk on a custom P-14 action. 2500 fps with 270 speer and health dose of RL15. Did not build but bought from the builder. Pretty hard on the shoulder but accurate. I also like the different calibers, more interesting. Don't know what happened to the builders reamers and other guns as when he passed his wife unloaded everything and left town. Too bad as there were other interesting rifles.
 
Potashminer said:
I have a 9.3x57 and a 9.3x62; also is several 30-06 here. Those barrels not going to do you any good - you will need a barrel with 9.3 mm groove size, or .375 groove size to make those wildcats - 30-06 barrels will need to be reamed to larger bore, then re-rifled, then re-chambered.

As per article by John Barsness - a "Scovill" wildcat - based on 9.3x62 - is going to pretty much maximize case volume for 30-06 size head and still give you a usable shoulder. I think much more is probably possible with rebated rim design (30-06 / 9.3x62 rim with larger diameter case body).

FYI - is no small thing to convert a military Mauser 98 to a hunting rifle action - remove stripper clip guide, drill and tap for scope bases - alter bolt handle for scope clearance, replace the military safety and often replace the bolt shroud, often want a hinged floor plate (or a detachable magazine set-up) , then "magic" polish / grinding to feed rails on underside of action to get the cartridge of choice to feed slickly, polish down the action and re-blue - install and headspace the barrel. Has been done a gazillion times over the years, but does not make it an "easy" thing to do. There were MANY FN 98's made over the years - the last run was chambered in 30-06 for the Belgian Navy and their Army - might be the "best" ones to start from?
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Thanks for the reply. Of course I know the bore for a 30-06 is too small for a 375 bullet. I just mentioned it because of the chambering - in theory, the chamber should be able to be re-cut for the difference in shoulder, neck and throat, and the barrel would be opened up to 375. For the gunsmiths out there - is this practical, or should I be shopping for a new barrel too? And the action is not from a military mauser. It was a Husqvarna 30-06, before I took the gun apart. I also have the commercial bottom metal and box mag, etc.
 
Canuck65 said:
Thanks for the reply. Of course I know the bore for a 30-06 is too small for a 375 bullet. I just mentioned it because of the chambering - in theory, the chamber should be able to be re-cut for the difference in shoulder, neck and throat, and the barrel would be opened up to 375. For the gunsmiths out there - is this practical, or should I be shopping for a new barrel too? And the action is not from a military mauser. It was a Husqvarna 30-06, before I took the gun apart. I also have the commercial bottom metal and box mag, etc.
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Reboring your existing barrel may be possible, depends on the outer diameter of the barrel. Ron Smith does this kind of work, perhaps check with him. - dan
 
Canuck65 - the 9.3x62 that I have was a Husqvarna Model 649 - had the "swing over the top" three position Mauser 98 leaf safety - I also have a Zastava 458 Win Mag - one got the Dakota three position horizontal swing safety; the other got the Gentry version - I did both here at home - so is a "home shop" doable thing to install them. FN and Parker Hale made "left" side up/down two position safeties that were close to drop in for converting a Mauser 98 military shroud to use a scope; Dayton Triaster / Timney / Buehler and other made "right" side ones that usually require a slot to be cut into the shroud for them to work. I suppose it depends on which side of the bolt that you think the safety should be.

If you are going to play with a Mauser 98 action, is very worthwhile to get the book "The Mauser M91-M98 Bolt Actions: A Shop Manual" by Jerry Kuhnhausen. Along with that one, is "Mauser Bolt Rifles" by Ludwig Olson - and then was several books like by Roy Dunlap that will show how to do many of the conversion steps from milsurp to sporter.
 
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Potashminer, thanks, I will check those books out. The action I have already has the bolt handle and safety converted for scope use, and it is already drilled and tapped (As I mentioned, it's from a Husqvarna sporter). My question was more about the practicalities of converting a barrel, and a comparison of the performance of the two cartridges.

That said, I do have a couple of military actions that I'd be interested in re-purposing, so I'll definitely check out the books you've recommended.
 
Some time ago, Tradex was listing 9.3 mm barrels that were threaded for Mauser 98 (I think?) - I know they are no longer in business, but might be some barrels like that, still available somewhere? I have no clue what they cost - then or now. From swapping factory take-off barrels here - can become royal PITA to get headspace correct, and the iron sights at top-dead centre - without re-chambering that barrel - some were before I owned a metal lathe - mucking about to make thinner or get fatter recoil lugs to get the headspace, bolt face clearance adequate, with sight holes at top dead centre. Last one that was done was perhaps 3 days ago - owner was not interested about iron sights - ended up circa 1:00 o'clock when headspace correct, using factory recoil lug. I have changed out a few Remington 788 - 308 Win into a 243 Win and vice versa - also straight install 308 Win onto an orphan receiver - no clue what it was originally. Might be a bit easier with a Mauser 98 - I think that internal bulkhead within the front receiver ring helps "home guy" set that barrel. I am only part way on first one - I used an action mandrel from Brownells - sure enough, the previously used action was not "square" at the very front, to the barrel tenon threads - but after a session on my lathe, it is now.
 
I have a factory Husqvarna in 9.3x62, and I've had a couple of .30'06's. The outside barrel dimensions are the same. The Swedes were obviously comfortable with fairly thin barrel walls at the muzzle, whether the gunsmith doing the reboring would be as comfortable would be an individual thing. Going from memory the muzzle diameter on my 9.3 is .595". They make for a muzzle-light, but nicely balanced rifle.

The barrel blanks Potashminer is talking about come up fairly regularly on Switzer's auctions, if you're looking for a 9.3. Personally I don't think you're going to gain much performance 9.3 vs .375, but I'm not going to try to talk you out of building something unique if that's what you're looking for. Check the reamer exchange sticky at the top of the page, you might find what you're looking for.
 
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