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which caliber to convert to?


mr fixit

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I'm curious about which round to convert a couple Mausers to.  I have a Yugo intermediate action, and a standard length La Caruna action both originally in 8x57.  Considering getting them to feed smoothly, what would be an easy caliber conversion?  How much trouble is it to get say a .270 to feed smoothly?

I would like to chamber them in something that would be easy to find ammo for. 

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My vote would be 7x57 if you're dead set on not using 8x57.   I haven't bought any ammo for a while, but 7x57 always used to be one of the more common country store-type calibers.  My personal favorite rifle is a 7x64, but you did mention easy to find ammo. ;)  It's a personal thing, but I have a prejudice against .270Win. as a result of a bad experience with a sweet old guild gun that was rebarreled to it years ago.  .270Win. is a pretty high pressure round.  Sure a GOOD M98 should handle it easy, but... well, like I said, it's just a personal bias.  That said, out to 200 yds. the 7x57 will do just about anything the .270 will. 

8x57 ain't no slouch though!  Is it simply preference or are the existing barrels trashed?   If "easy to find" is the #1 criteria though, you can't go wrong with .30-06 and .308Win.  

BTW - I think that .270 barrel is still in the shop somewhere.  If you're interested I'll make you a deal on it. 

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27 minutes ago, MorgansBoss said:

My vote would be 7x57 if you're dead set on not using 8x57.   I haven't bought any ammo for a while, but 7x57 always used to be one of the more common country store-type calibers.  My personal favorite rifle is a 7x64, but you did mention easy to find ammo. ;)  It's a personal thing, but I have a prejudice against .270Win. as a result of a bad experience with a sweet old guild gun that was rebarreled to it years ago.  .270Win. is a pretty high pressure round.  Sure a GOOD M98 should handle it easy, but... well, like I said, it's just a personal bias.  That said, out to 200 yds. the 7x57 will do just about anything the .270 will. 

8x57 ain't no slouch though!  Is it simply preference or are the existing barrels trashed?   If "easy to find" is the #1 criteria though, you can't go wrong with .30-06 and .308Win.  

BTW - I think that .270 barrel is still in the shop somewhere.  If you're interested I'll make you a deal on it. 

 

I'm interested.  As far as why not 8x57......I'm taking off the military barrels and replacing with sporter barrels to get the smooth lines and no military curves.  Just going for looks, but since I am replacing them I need to pick a caliber.

I guess my question should have been what replacement barrel calibers are 'plug and play'?  I assume either 8x57 or 7x57 would need very little work to feed well.  If not those calibers, what are the next easiest to get to feed well with the least work?

I have thought for years a 7x57 would be sexy. Mainly because of the 'mystique" and history of the round.  I have very seriously considered a custom 7x57, and stamp the barrel ".275 Rigby" cause I'm just weird like that.

As for .270....I love it.  My main rifle is a factory Remington 700 from the era of pressed checkering.  I bought it used as a teenager in the 80's because I had read about it in Outdoor Life so often.  It has never let me down.

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I was gonna say 7x57 but I didn't think it fit your criteria.  But I like the round, mostly for the history.  Have you read the thread I have on it?  That's everything I know about them.

The Spanish redid their 7x57's into 308's by (near as anyone can tell) boring out the shot out 7mm barrels, cutting some grooves, turning down the chamber end a tad and rechambering.  So, I would infer from their experience that feeding issues with small ring Mausers going to 308 shouldn't be much of a problem.

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47 minutes ago, Dr.Hess said:

I was gonna say 7x57 but I didn't think it fit your criteria.  But I like the round, mostly for the history.  Have you read the thread I have on it?  That's everything I know about them.

The Spanish redid their 7x57's into 308's by (near as anyone can tell) boring out the shot out 7mm barrels, cutting some grooves, turning down the chamber end a tad and rechambering.  So, I would infer from their experience that feeding issues with small ring Mausers going to 308 shouldn't be much of a problem.

both of mine are large ring

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I would say 7x57 is the the closest thing to plug-n-play, plus barrels, reamers, and ammo are easy to come by. Another easy plug-n-play is the Sweedish 6.5x55.  The 8x57 is another obvious fit but, sporter barrels are a little harder to come by.

The 7.65x53 Argentine is another catridge that feeds very well but, once again reamers and barrels are hard to find.

Longer cartridges like the 30-06 can be readily made to chamber but they do require extra work.

I've done a couple 308s and they don't feed all that great in my opinion, at least not without extra work.

I have 2 military 308 conversions, 1 Israeli lg ring and a Spanish sm ring, neither feeds worth darn.

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I was at one time a big fan of 270 having followed Jack O'Conner reading Field & Stream magazine in my high school library. I believe it was my second rifle of many (to many actually), a Remington pump. Being that you already have a 270 before selecting a caliber. Think about the need or niche you're trying to fill. Small caliber something like 22-250, large 35 Whelen or 35 Winchester. For a nostalgic choice 7X57 is great if you're a handloader.  In my thinking you're filling the same niche as 270 but having bragging rights on a 275 Rigby project you built, kinda cool in my mind. 

I've had bad luck in the past with late 40's to early 50's Spanish 8X57 receivers. I believe they were Oviedo but way to many years ago to say for sure. Net chatter claims the 8X57 Spanish Mauser the metallurgy is inconsistent. I had one take the female threads out of the receiver pulling the barrel. The other re barreled to 308 developed a headspace problem. According to a gunsmith it was receiver set-back claiming the metal was to soft. Might be shooting dice if you're not willing to spend the bucks having the Spanish receiver heat treated. If I recall it correctly back in the era PO Ackley was building sporters. He refused to rebarrel certain Spanish Mausers without him heat treating first. I believe he also refused to do magnum conversions on Spanish recievers. Ackly's hey-day was way back in the 70's and I could have the facts wrong.

I recomend if your Oviedo is in original military configuration, peddle it to a collector and take the bucks to a gun show. I haven't been very active as I once was visiting gun shows but I do recall seeing plenty of dirt cheap prices on Mauser bubba'd sporter projects often with matching bolts. 

WARNING!! After building your first expect to become addicted and building more, welcome. 

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On 1/29/2018 at 10:48 PM, AzRednek said:

I haven't been very active as I once was visiting gun shows but I do recall seeing plenty of dirt cheap prices on Mauser bubba'd sporter projects often with matching bolts. 

WARNING!! After building your first expect to become addicted and building more, welcome. 

The two rifles that get more use than all others combined at my place were built from two such "sporters" and a non chambered 7mm barrel (I reamed to 7x64), all bought for $100 about 15 years ago from a dealer that specializes in "collectables."  He was thrilled to get those atrocities out of his shop. So was I. :D  Jack O'Conner introduced a whole generation to the .270 Win.  To that end, as I recall from reading everything he wrote for years, even his mountain rifle was a 7x57!  He was a big sheep hunter and I believe it was a lightweight outfit thus, being the attraction for toting on vertical trails.    

Just about any .470 head size and within 0.10 inch in length from the 8x57 should be a painless adaptation. Shorter cartridges sometimes benefit from mag. blocking, but that's a simple operation.  My personal recommendation as your first project is narrow your preferred list, weed out any that may not be an easy conversion (overly large or small head sizes, long lengths and any rimmed round), then shop reamer availability.  Gunsmithing is not as much hocus-pocus as many think.  98% is how much patience and mechanical understanding you have.  Plan on it taking twice as long as you first expect if you want to be proud of the finished product. 

Oh, one more bit of advice.  If you scrimp now, it will show later.  I'm a huge fan of not buying anything I can make, adapt or fix, but how many would make their own car fender from a piece of sheet metal bought at Lowes after hitting a deer.   ;)

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The Yugo should be able to handle 308. A lot of Yugo rifles were turned into 308 rifles.  

I have a questions are these rifles in their original stocks? If they are by the time you find stocks, barrels, chamber reamers and head space gauges you could buy several hundred rounds of box style brass in 8MM, reload it yourself. The days of cheap rifles like mauser's seems to be over and a lot of these rifles have been sporterized. So a rifle in its original stock even if numbers arent matching will have a value someday. 

Plus sometimes when you replace barrels you can damage a receiver

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  • 3 weeks later...

If you want Sporter calibers, you can get a pre-threaded, short chambered 98 barrel in 25-06 for about $130 from ER Shaw. #1 contour, 24" length. Should feed with absolutely no problems. They also have 30-06 and .308 Win barrels in the same configuration for the same price.

Ok, having said that. If you choose to go with 25-06 or 30-06, you will want to lengthen the mag well opening by about .100". Pretty much a necessity for the 30-06, optional for the 25-06.  Easy to do.  Mauser actions are designed around a tapered cartridge, and the 25-06 and 30-06 are just about perfect for this.

Now, if you go this route, you can get left over Santa Barbara made blued hinged trigger guards from Numrich for about $60. They are made much better than some of the aftermarket Mauser hinged trigger guards out there. There are also hinged aluminum trigger guards on eBay for $65 - $70, and they take about a 1/2# off the weight of the rifle.

The .308 Win barrel would be great on the Yugo action. I have just finished installing and headspacing an Interarms MkX .243 Win barrel to one of my Yugo actions. You can pick up a short chambered, prethreaded .308 Win and .243 Win barrel from Numrich for about $140.  (More than likely made by ER  Shaw) I'm working on the stock, and I think that I've figured out how to make a nice looking hinged trigger guard for the Yugo action. I've just got to work it through in my head more, and find someone with a TIG welder.

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