Home Forums Hunting & Shooting Gunsmithing M77 barrel in a 98 question

I have got an intermediate length action mauser 98 that was chambered in 25-06 years ago. I had my doubts at first but it does appear to be a large ring. The magazine isn't really long enough for the rounds unless you seat the bullets deeper then spec. This gun is just aching for a rebarrel or at least a rechamber to something a little shorter.

So....I have a ruger MkII in 280 that I would like to rebarrel one of these days to a 24" heavier contour. Would it be possible to cut this old 280 barrel back a bit, clean the chamber up to a 7x57 and screw it into my 98? I'll check with my smith when the time comes but I just wanted to get some opinions on this idea first.

Am I dreaming something up not possible? Thanks!

Just about anything is "possible"...the question is, is it more practical and economical than just purchasing a new barrel and having it installed.

First thing your smith would need to do is determine if there is sufficient barrel diameter for the new chamber and larger threads once the threaded portion is completely cut off the Ruger barrel.

Also...and this is sure to get some dissenters...all chambers and reamers are not created equal and assuming that your 7x57 reamer is going to just "clean-up" the .280 chamber is assuming an awful lot.

Setting up to chamber a barrel that already has a factory chamber in it is often more time consuming and difficult than cutting a new chamber from scratch. Factory chambers are cut with non-piloted reamers and they are notorious for being non concentric to the bore and slightly oversized.

Thanks!

Yes, the goal would definitely be to save money. If it ends up costing more reusing the barrel there wouldn't really be a point to it.

How do the M77 threads compare to a large ring mauser? Smaller diameter and totally different count? I was thinking they might actually be pretty similar since they more or less copied the design.

Sorry "clean-up" wasn't the right use of terms, the 7x57 chamber has a little more taper then a 280 right? Probably take .5" or more of set back to clean up the 280 chamber you think?

the ruger thread count and tenion diameter is smaller than the large ring mauser. by the time you cut off the old threaded portion and rethread you might not like the looks of the barrel with a short cylinder in front of the action. after you cut off the old end i think you will have shortened the original chamber enough to chamber the 7x57 with out problems

There's an old saying about tripping over dollars to grab for nickels that comes to mind every time I hear someone asking about what you describe.

New rifle barrels are not all that expensive, and you certainly wouldn't have to go with a top of the line barrel to match or even exceed what you would get by doing what you are contemplating.

The threads aren't even close. A large ring Mauser has a 12 TPI 55� Whitworth thread and a major diameter of 1.100". The Ruger has a 16 TPI 60� thread with a .998" major diameter. In other words...the entire threaded portion of your Ruger barrel will need to be removed. That will shorten the breech end, and the existing chamber, approximately .690".

The trouble with rechambering an existing factory chamber of similar diameter is that if the original chamber is not concentric to the bore your new reamer is going to try and center itself on the bore and you can end up having a chamber with a slight dog-leg where the old chamber stops and the new portion continues forward because there is not enough difference in size for the new reamer to cut and true the entire chamber. It's only cutting the forward part.

Ah you posted while I was typing ...

It looks like it would take about at least .75" off barrel to cut the thread off. That would leave about .75" for the cylinder portion of the barrel. Sounds a little short, no?

Thanks to you both, any opinions on the short chambered Adams & Bennet barrels from MidwayUSA?

A&B would, at least, perform on par with a factory barrel.

I agree.

I am hardly a fan of AB barrels but even as bad as they can be they would probably out perform such a hack job as this would end up being.

Just my opinion.

But, then.............If you did it, rifle loonies fifty years from now will be arguing whether it's an unknown model of Ruger, or if Ruger owned Mauser, or if Mauser owned Ruger !

ER Shaw will furnish you a barrel for your action cut, threaded, and chambered for $166 shipped. They will install and test fire the barrel for you for an additional $70. They offer many different chamberings and they could blue the barrelled action for you if you want for $100 for premium polish and blue or $90 for matte blue.
They make a very nice, modestly priced barrel.

Well...they are modestly priced...that's true.

Yes you get what you pay for no doubt. This is not a project I was wanting spend a lot of money on nor was I expecting to get a $2K custom rifle that shoots 1/2 moa groups from the work either. Basically just wanting to change calibers. "Factory" or "off the shelf" accuracy is just fine.

That said , I'll just save my money for a douglas or shilen CM blank. MidwayUSA actually has a little better prices then I was expecting.