Reboring a 7x57 RB to ? caliber

[Gaucho Gringo]

I am looking at 7x57 Remington rolling block. I just emailed the seller for more pictures of it. He says the barrel is sewer pipe but he had a gunsmith check the rifle and supposedly the action is tight and in good shape. Does anyone know what calibers it could be relined to or maybe just rebored to a larger size? Thank you.

 

[Unka-Boo]

http://www.youtube.com/watch?v=wkVwI3L6VAg

This is the first thing I thought of....I think SGN had an article a couple of years ago doing the same to a Martini.

 

[osprey176]

The relining procedure is good for rimfires and low pressure centerfire rounds.The 7x57 is too high pressure to reline,I think.You could rebore to any similar pressure,larger caliber round,like maybe 8x57.If it were my rifle,I would most likely just replace the barrel.Unless of course,the rifle had a high collector value.

 

[dprice3844444]

rebarrelling a Remington rolling block google this

 

[Jim Watson]

You could rebore to 8mm which would leave the basic 57mm Mauser chamber and rimless extractor alone. Clearwater charges $350 to rebore, rerifle, and enlarge the neck on the same chamber. Assuming the chamber is not as rough as the 7mm bore.
And assuming you are willing to stick to mild American 8mm and not shoot the hot European stuff.

Anything else, you had just as well rebarrel, a good rebore is an expensive one-off these days, although they used to be an economical way to salvage a barrel.

 

[wlewisiii]

See if the folks at www.35caliber.com would be able to bore it to .38-55?

 

[tahoe2]

+1 on the 38-55... a traditional and low pressure round for that Rolling Block!

 

[Edarnold]

I am looking at 7x57 Remington rolling block. I just emailed the seller for more pictures of it. He says the barrel is sewer pipe but he had a gunsmith check the rifle and supposedly the action is tight and in good shape. Does anyone know what calibers it could be relined to or maybe just rebored to a larger size? Thank you.

If you are planning on making the investment of Reboring or rebarreling this RB, you should check to see if it's the 1897 or 1902 action. The 1902 is made with better steel and heat-treatment and is much stronger than the earlier type. I believe the distinguishing features of the 1902 are the rotary extractor and a somewhat shorter hammer spur.

You would want to stay with the .473" case head or larger, anything smaller would mean adding metal to the extractor hook which would be a pain. Also, since the headspace on many of the South American 7x57 rifles was made to match Remington's ammunition, and is often too long for current manufacture ammo, the rechambering and reboring to 8x57 might result in excess headspace. A longer case would clean up the chamber: reboring and rechambering to .30-06 would be a good choice. Rebarreling would give you more caliber choices, but I'd check with your gunsmith on the additional machining needed to cut the clearance for the breechblock and the recess for the extractor. If I remember rightly, the barrel threads are also very different from the usual V-shape. The extra machining might bring the rebarreling cost higher than reboring.

IMHO

 

[natman]

A longer case would clean up the chamber: reboring and rechambering to .30-06 would be a good choice.

It might be a good choice in terms of cleaning up the chamber; I'm not so sure about the pressure level in an older RB.

 

[Abel]

38-55

 

[morcey2]

...

Also, since the headspace on many of the South American 7x57 rifles was made to match Remington's ammunition, and is often too long for current manufacture ammo, the rechambering and reboring to 8x57 might result in excess headspace.

...

The distance from the bolt face to the shoulder on the 8x57 is just under 0.100" longer than the same dimension on the 7x57. Even on a rifle reamed for larger headspace, it should clean up nicely to 8x57 without excessive headspace.

I'm a huge fan of 8x57, but I think a 38-55 would be perfect for this. But, is the sewer-pipe bore really a sewer pipe bore? I have finn-captured mosin that has a bore that looked really bad when I got it. It looked a little better after I cleaned it, but was obviously very frosted, dark, and somewhat pitted. But it shoots 2" groups at 100 yards with iron sights and surplus ammo.

Matt

 

[Jim Watson]

.38-55 is a sweet little round but it will not clean up a 7mm chamber.

Hey, I did not realize that an 8x57 actually had a longer headspace dimension than 7x57.
So that would let you eliminate the traditional headspace problem on the rolling block.
But it will also increase the cost of the rebore.