Can the magnum boltface on a .700-inch diameter bolt be hogged out to fit the .579-inch face of a 460 Weatherby Magnum? I have an MRC long action chambered for 300WSM. Feeds very poorly-- so bad, I shoot it only as a single shot gun. I want to cut the 460 cases to 2.440 inches long, form a 30-degree shoulder and neck the mouth to fit a .30-caliber bullet. I want to save my barrel. This will be a new round. The 300WSM case is .555 at the base datum; no other case works to wildcat this round. The 300RUM is too small by about .011 inches there, so it's not a candidate. The 460 is big enough-- it's .604 at the belt, which may be removed or just have the chamber cut to obviate it by .002 inches and have the round headspace on the shoulder. Any gunsmiths or machinists know the answer to my question? Thanks so much...

Yes, it can be opened up that much. I have a MRC long action I opened up for .416 Rigby which has the same case head diameter.

Sorry that this is not your initial question, but have you thought of using either Rigby brass or 338 Lapua brass, as John has said, they're the same as the big Wby cases base size but should give more mag space, the Wby belt might compromise this. I'd say they might be easier to make feed better but there'll be a queue to bollock me for suggesting such a thing so I won't mention it.
Steve

Thank you, TmT and Shinzo, for your replies. I am using the visual comparator over at ammoguide.com to find a suitable candidate for this conversion. The belt on the Weatherby cases is really not needed; it was just a marketing ploy in the 1960s when the round came out to tell shooters the new round was so powerful, it had to have the belt. I can remove it or just cut the space for it a little deep and it's not part of the equation. I don't need to have three or four rounds loaded. I shoot bench-only with the gun and only then as an amusement. It's a toy, not a serious competition gun. Considering that TmT has done it, I now know it can be done. And now, back to research on how to actually make the brass. I think Rigby brass is available as a cylinder item?

No problem to open up the bolt face and feed rails for that conversion.

weatherby and rigby bolt faces are NOT the same ... the rigby is SIGNIFCANTLY larger.. .590 vs .560, as the weatehrby brass is quite rebated.

Doesn't matter what the "old drawings" say, put calipers to brass.

Yes, a .700 can be opened up for either

Great information!

quote:

This will be a new round.

Yes and no! Have you ever heard of the .30/.378 Arch? It was the .378/.460 Weatherby case cut to 2.25" and necked to .30 cal. The problem you will run into is trying to neck the brass down without collapsing it. Dr. Arch did it hydraulically and it was quite a process. I ruined several boxes of very expensive .378 Weatherby cases without making one usaeable Arch case. For more info, check out Volumn II of Ackley's Handbook for Shooters and Reloaders, page 442.

I really can't believe all this BS about belted vs non belted cases. I never in 40 years saw a problem WITH a belt...doesn;t do a darn thing to either enhance or or cause feeding "problems" Oh Yeah! gun writers love to have something "new" to bash.

Without that, they would be out of a job! The fact is that a belt CAN be a secondary headspace option...not bad, and easily measured. The shoulder can be way off the map, but the belt will keep safety under control.


I'm neither advocating nor condemning the belt..., but Holland and Holland had a darn good reason to design the belt...that reason is still valid

Below is the sketch of the proposed round. I call it the 30-416. It's on a 416 case, shortened to 2.5 inches, shoulder diameter of .555 inches (same as base datum of a 300WSM) and a shoulder angle of somewhere near 30 degrees. Just slightly longer than a .30-06, not as long as a 300Win or 300RUM but larger in diameter. The idea is to totally wipe out the 300WSM chamber in the gun and cut a new one that's closer in tolerance than the SAAMI chamber there now, hopefully leading to greater accuracy. Being .400 inches longer than a WSM, feeding should not be a problem.



Image from ammoguide.com, a great place for megatons of tasty gun-related information. I have to give them the screen credit. Their Cartridge Creator is really cool. You can enter any or all of the dimensions, hit Display, and instantly see your inputs to .010 inches in accuracy. Neat!

Lots of Siamese Mausers have been opened up for the .605 rim of the .45-70.