I've had a Weatherby Vanguard in .300 Wby Mag for a while and I'm starting to get bored. I want a new and more powerful rifle. How much would it cost to rechamber/reream/rebarrel a .300 Weatherby to a .340 Weatherby? Thanks.

You're talking two different bore diameters. You would have to re-barrel, not re-chamber. Unless you want to put a lot of money into ityou'll be better off buying a new rifle.

Back in the 1950's and 1960's, there were a number of barrel makers who would ream/re-rifle a barrel out to a larger caliber. One of the most common was taking a shot-out 30/06 barrel and reaming it up to .338/06. You almost never hear of anyone doing this these days. Depending on the quality of the new barrel, a complete re-barrel is going to cost you in the $325 to $450 range.

To have it rebored, re-rifled and the chamber opened up, it will cost you about $350.00 or so. A new barrel would cost around $400.00 UP. That's more than a Vanguard would cost!

The problem with reboring is the time you must wait for the work to get done, but a rebore job by a reputable 'smith is usually excellent! Often better than the barrel was in the original caliber.

Barrel - 300+

Rechamber 150+

I am looking at rechamberin a 22-250 to an ackley for the heck of it...