converting 7x57 into a .257 Roberts ?

[TexasPatriot.308]

I own lots of firearms, but not a firearms expert. I know the .257 Roberts is derived from the 7x57. I have an old custom 7 mm mauser that I have no use for, but am looking at getting a .257 Roberts, can this mauser be rebored into a .257 and what would it take. I know lots of you guys out there are very knowledgable, appreciate any input.

 

[1948CJ2A]

By the time you buy the barrel and pay for all the gunsmithing (install barrel, turn bolt for scope, chamber & test fire, and polish & blue), you'd be better off keeping the 7x57 and buying a new or used 257 Roberts.

Both the 7x57 and the 257 are outstanding. I'm curious what use you have for a 257 if you have none for the old 7x57?

 

[morcey2]

I've got both. Since the 7mm has a bore that's already larger than 257, reboring isn't an option. If the 7x57 just doesn't shoot well and you want to rebarrel it, 257 Bob is as good a choice as any. If you just don't like the 7x57 and want the same gun in 257 Bob, go for it.

But, like 1948CJ2A, what use would you have in a 257 that wouldn't be filled by a 7x57? I've got both and both will do everything from varmints to deer quite well. 7x57 can do elk with the right bullet, but that's what I have a 30-06 for. (or 8x57. )

Matt

 

[TexasPatriot.308]

I have never owned a .257 Roberts, got plenty other rifles. fixin to be 60 and got no use for anything more than a .308. the mauser was given to me by a friend, no markings on barrel or anything, he hadn't shot it in 30 years and it was given to him by another friend. it just sits in my safe, guess I can always put a scope on it and fire it anyway (vise it down and pull trigger with string first). anyway I am gonna buy me a nice .257 Roberts I guess....just cause.

 

[denton]

If the 7x57 shoots decently, it is pretty hard to come out ahead on a customization project.

You can put the money into a new barrel, plus the cost of mounting the barrel, and still have one gun.

Or you can put the money into buying a 257 and have two guns.

This from the guy that has about five custom Mausers....

 

[LAGS]

I rebarrel a Mauser to .257 Roberts and it was a Very nice rifle.
And I have two barrels for the Large Rings in the .257 to convert others when I feel like it.
But you didn't say which Mauser you have and want to convert, or if things like if the receiver is drilled for a scope, or the bolt has been turned down yet.
We cant give you proper advice if we are lacking information.
If the rifle has been Sporterized already, and you just have to change the barrel out, then I would give you the thumbs up for this project.
But if it is a rifle that needs a lot of other work like the bolt and drilling for a scope, it can get cost prohibitive unless you are doing a lot of your own work.
Also, the Small ring Mausers like the Spanish, can be converted to .257 , but The Pre threaded Barrels are harder to come by than are for the Mauser 98 and similar actions.

 

[morcey2]

What's the action it's built on? I don't think there's any better reason to change it than "just because." Works for me. If it's a Mauser action, either small or large-ring, rebarreling it shouldn't be a big deal. I built mine on a Yugo-captured K98 receiver with an Adams and Benett (now Green Mountain) barrel. Mark Skaggs did it for me and he did a great job. Also, if it's a large-ring mauser and has a barrel longer than 22", I might be interested in the old barrel.

I say go for it.

Matt

 

[JerryMander]

You know, you could always take the 7x57, get a stenciler, and write ".275 Rigby" on it. Brand new rifle.

If it ain't a 1893 mauser, I'm sure some people on the forum would be interested in it.

 

[DRYHUMOR]

There's an outfit over in Hempstead, called precision Barrel Work. I have a rifle they built with a Shilen barrel in .257 Roberts. It's a shooter.

Looks like it's just down the road from you; might be worth a call and trip to see what they can do for you. 979-826-2563

 

[Onmilo]

"Custom" Mauser means a lot of Things
.257 Roberts is about the same overall as a .30/06 or .270 so you will need a Model 98 action for best feed and function.
As stated, you can't rebore a 7mm (.264") Mauser to .257 (6.5mm), it will need a new barrel.

 

[Abel]

7X57 is way cooler than a Bob. Leave it as is.

 

[morcey2]

7X57 is way cooler than a Bob. Leave it as is.

Can't be! The parent can never be cooler than the kids! Except in my case. I'm much cooler than my kids. They still haven't learned to appreciate a good mullet.

Matt

 

[Abel]

Too funny.

 

[denton]

The 257 is based on the 7x57 case, which makes a bit shorter than 30-06 and 270. They work very well in an intermediate action, such as the Yugo. Since the Yugo can't be made into a 30-06 length firearm, they are not very popular and don't command much in the marketplace. You can get an 8x57 for around $175 if you shop.

If I wanted a 257, that's probably where I would start, rather than breaking up a working 7x57.

 

[TexasPatriot.308]

the 7x57 I own has a Mauser action and is has scope rings on it. the irony is I took this rifle to an old friend of mine probably in his late 70s, early 80s, retired gunsmith that still works on firearms for friends. He went to Colorado last summer to visit his son and do some varmint shooting, had a heart attack while out there and his doctor wont release him to come home, so my rifle is in his safes so one of these days I will find out from him what he thinks and I value his opinon highly. I just took it to him to see if it was safe or not as safety was not working properly. just might leave it the way it is when he comes home. Meanwhile I am gonna treat myself to a .257 Roberts for my 60th birthday.

 

[MachIVshooter]

I think I'd leave it 7x57. Nothing wrong with the Bob, but the 7mm Mauser is a more versatile cartridge.

you can't rebore a 7mm (.264") Mauser to .257 (6.5mm), it will need a new barrel.

.257" is 6.35mm; 6.5mm is .264" cal

 

[LAGS]

@ Denton
That is why I have spare .257 barrels, as I have several Yugo 24/47's that are not in good enough shape to restore.
So those get built into .257 .243 or.308's
I love that mid length action.

 

[epoletna]

PM me if you wanna sell that 7X57 -- I'm in the market for one. Fred

 

[HOOfan_1]

I think I'd leave it 7x57. Nothing wrong with the Bob, but the 7mm Mauser is a more versatile cartridge.



.257" is 6.35mm; 6.5mm is .264" cal

Depends on whether you are talking bullet diameter or bore diameter

English units usually go by bullet diameter

.224"=5.68mm
.243"=6.17mm
.257"=6.53mm
.264"=6.70mm
.277"=7.03mm
.284"=7.21mm
.308"=7.82mm
.311"=7.89mm
.323"=8.20mm

Lazzeroni named their cartridges with metric names by the bullet diameter.

Land diameter of the 7x57 is. 275" though