Home Forums Hunting & Shooting Ask The Gunwriters Mechanics of a rebore

Can someone answer a few questions about reboring. Lets say you have a 308 rifle and you would like a .358 win, or you have a 22-250 and you want to make a 250-3000. What is actually reboring? Do they actually cut the bore larger diameter and then rechamber? What are the limitations on the doner barrel (i.e., barrel thickness?) Obviously there would be some limitation on thickness if your making the hole alot bigger but is there some formula to calculate what is feasible?

In reboring, the old bore is reamed out and then cut-rifled. If the basic chamber is staying the same, say from .308 to .358, then usually the neck/throat portion only is enlarged. If there's an actually change in the chamber, say from a standard to Ackley Improved round, or from a standard round to belted magnum, then an entire new chamber gets cut.

Exactly how large the barrel diameter must be can depend on the type of steel and exactly who's doing the rebore, but generally at least .15 inch of barrel thickness around the bore at the muzzle is sufficient. In fact my Savage 99F .358 only has about .13 inch of steel around the hole at the muzzle.

+1 on the above description of the rebore process. I believe that you mean your .358 has .130" wall thickness not .013".

Is there information available that will tell us which chambers can be cut anew from a previous chamber?

I have an old rifle that has a really thick Buhmiller barrel. It's a 22-250. I would like to make it into a 6.5mm-06. The barrel is 28 inches. I think it would be fun to shoot. Who does this kind of work? Thanks

Relode28,

A look at cartridge dimensions in a reloading manual can provide a good idea of which rechamberings are possible. Setting the barrel back a thread or two makes some other possible.

Of course. Certain shops that do this work can tell you if a certain reamer will "clean up" an existing chamber without setting the barrel back. Thought you might know if such a list existed.

hanco,

Apparently only four people are doing rebores in the U.S. these days, and one of them isn't taking on any new reboring jobs because his schedule's full up. The other three are:

Classic Barrel & Gunworks
339 Grove Ave.
Prescott, AZ 86301
www.cutrifle.com

High Plains Reboring & Barrels, L.L.C.
243 14th Avenue NW
Turtle Lake, ND 58575
nrjonsnwestriv.com

JES Reboring
715 South 6th Street
Cottage Grove, OR 97424
www.35caliber.com

Thank you very much. I don't know if Buhmiller built rifles or only made barrels. It's an old 1917 action, beautiful stock, and a great trigger. No markings except Buhmiller on the barrel. He was one if the early writers for Handloader.

Hanco, I've read a bunch about JES, all of it good.

JES is very good, but don't know if he rebores smaller than 35Cal.

I've had two rebores, one by Cliff LaBounty, 30-06 to 35 Whelen and the other by JES, 30-06 to 375 Whelen. JES does great work and has a fast turn around. I had the 375 back in 10 days.

JES recommends having a muzzle diameter of at least .20 over groove diameter or at least he did the last time I talked to him.

I like reboring as an option to move up in caliber, try a new cartridge or restore a pitted barrel. You get to keep the same barrel and sights and it drops right back into the original stock with no fitting.

I've also used Oregunsmithing and Al Siegrist, Oregunsmithing years ago, and he still advertises the service. It took a couple tries with them, but I was satisfied (.30-06 to whelen) and had Mr. Siegrist do a .30-30 to .38-55 this year. Very happy with that rifle.

Not sure if MD looked into them.

Old70

Butch,

JES does .338's now, and several calibers up to .50. He's planning to do some more calibers, but only in the larger range he's doing now.

old70,

Thanks for the info. Did not know about Mr. Siegrist. Will look into him.

How do rebored barrels shoot?

John,

Just for completeness, who is the fourth.

I thought for sure Danny was the one who's schedule was too full to accept new work. That's what his answering machine currently says at least.

Thanks,

Scott

I had my first rebore done in 1994 by Cliff LaBounty, the pioneer as some might say. His rule of thumb was .100" a side over bore diameter at the muzzle. Seemed OK to me given my factory tang 35 Whelen measures .558" at the muzzle. Make no mistake, a proper rebore will shoot very, very well. I have multiple rebores both rifle and sixgun that deliver.

Redman's Rifling & Reboring in Omak, Washington.

I've talked to Danny on the phone a couple of times in the past month or so, but apparently he answered, so I never heard the message. He did mention, however, that he was BUSY.

I have two rebores done by Al Siegrist. I believe he is still working. Mine are handgun rebores and are very fine.

Siegrist Gun Shop
Al Siegrist
8752 Turtle Rd.
Whittemore, Mi. 48770
989-873-3929