Will a .257 Weatherby chambering reamer clean up a 25-06 Remington chamber?

My diagram shows a .281" neck diameter for the Witherbee and a .290" neck diameter for the 25-06 Remington. Would I end up with a step in the neck?

Reason for asking is that I'd like to rechamber a 25-06 Remington T/C Pro Hunter 28" stainless fluted barrel to .257 Weatherby without having to go the custom barrel option.

No not cleanly.

Don't know if this will open
http://ammoguide.com/cgi-bin/aichamber.cgi
Given a currently chambered cartridge, list rounds that are candidates for conversion.
This advanced software analyzes the shape of cartridge cases.
(Thanks to Stephen P. Gibbons for suggesting this tool.)


Sorry, but based on your settings, you cannot ReChamber your .25-06 Remington firearm to .257 Weatherby Magnum because the case of the .257 Weatherby Magnum is too narrow at the top of shoulder.
NOTE: A qualified gunsmith can sometimes work around reported problems with special-case techniques not considered here, such as 'barrel setback'. Always consult with a qualified professional.





.25-06 Remington at AmmoGuide.com
.25-06 Remington
(Shoulder angle is estimated)
.257 Weatherby Magnum at AmmoGuide.com
.257 Weatherby Magnum



Try Again:


It says the rechamber won't work because of the dia at the start of the shoulder. AS\s I look at it for the base of the neck your dia would be too large resulting in overworking the neck. However since the 06 is shorter the top of the neck would be cut to Wby dia so yes you would have a stepped neck.

A thought that comes to mind if the neck is the only issue then use a neck reamer to cut it to the same dia. Yes the larger neck would overwork the Wby brass. How much not sure.

If you can set the barrel back I think you still have neck issues unless you can set it back far enough to remove the old neck. Doubt that.

Paul,

Thank You - I appreciate your prompt response.

I'm not sure where the idea comes from that there is a neck diameter discrepancy between two modern .25 caliber rifle cartridges. My SAAMI reference book doesn't show the .257 Weatherby, but this spec drawing shows it to have the same .290" O.D. neck as all other modern .25's, including the .25-06: http://stevespages.com/jpg/cd257weatherbymagnum.jpg

The body of the .257 WBY is longer than that of the .25-06, as is the base-to-neck dimension, so the chamber should "clean up" without any barrel setback.

The complication might come with a factory chamber which has a too-generous neck that is smaller than the WBY reamer's neck. But a competent gunsmith can ream the neck-only to the diameter of the original neck after reaming the body in order to make a seamless chamber.

All of that said, unless having the availability of $90 per box factory ammunition is important, rechambering to the .25/264 (.25/7mm Rem Mag) or even .25 STW is probably a better solution which avoids the Rube Goldberg radiused shoulder and excessive freebore issues of the obsolete Weatherby design.

Gerry
In reading my post I confused myself. I do agree with Stonecreek with the issue being in the neck. I don't have the SAAMI spec I have several sources showing CASE necks being smaller on the WBY I have no clue as to what the chamber is cut too. They may all be the same. As Stonecreek stated and I tried to say the neck could be cut smooth after the rechamber. If all 257 chambers are cut to the same dia then no issue.

Unless I had a 26" barrel and plenty of $$ to waste or simply wanted a 257Wby no matter what I would sure leave it as a 25-06. Nothing you would hunt with a 25 cal would know the difference when hit.

I built a custom short throat .257 Wby a couple years back and sold it early this summer. It was a neat gun but when the new wore off I went back to my .280 Improved 40° and 7mm Rem Mag. If it had been a .25-06 I might have kept it for ease and cost of reloading. The only creatures that find the .257 Wby more impressive than the .25-06 are humans.

I've been using a 25-284 for a couple years that really impresses me. Bout the same as the -06 version.

I've owned both.

I've liked both.

I've sold both.

My wife just bought me a Pre War Mod 70 .257 Wby. I'm tickled pink. I'll keep it.

But I prefer the .270 Win.