Home Forums Hunting & Shooting Winchester Collectors 300 RUM to 6.5-300Wby

Any foreseen issues converting a Model 70 Classic in 300 RUM to a 6.5-300WBY?

Pacnor said they can match the contour, etc. I’m just concerned about the feed ramps and feeding in general?

Any input is appreciated. Thanks!

The RUM has a mag box with windows for the fat round.

I’m thinking replacing that with a std mag box and follower.

Feeding should be OK with that set up.

DF

Quite the device. Y'all expecting trouble down there?

Not now.

Ha!

DF

Is the bolt face on the fat beltless RUM the same as for the belted .300?

Yes thanks to rebated rim.

DF

I built a .404J on a M-70 300 RUM donor. Had to open the bolt face to accommodate the parent round.

DF


Edited to add, why don’t you consider the 26 Nosler. Don’t think you’d need to change out anything.

Pretty close to the 6.5-300 Wby and no belt.

I'll trade your RUM mag box and follower for a 375 mag box and follower. Then you'd be able to go 6.5-300 with ease!

There ya go. Just what you need.

DF

The left hand feed rail on RUM actions has a cut-out that allows the cartridge to slip its wide butt out and under the extractor. I just converted a STW action to 375 RUM and had to dupe that cut to get it to feed from that side. Going the other way, I don't know what effect that cut-out might have on the feeding of a Weatherby round. A guy might want to make up some dummy rounds and see how it fed before investing in a new barrel.

The feed rails themselves are slightly wider on the RUM also. It has to be to allow room for the wider round to come up a bit higher so the bolt can catch the rebated rim on the RUM.

Welding up and remachining the feed rails could make finding a different action a bargain.

Another alternative: My guess is the 26 Nosler would feed fine in the present action and magazine box. The powder capacity of the 26 and 6.5-300 is just about identical, so they do the same things. Or at least that's my experience with handloading for both in 26-inch barreled rifles.

Agree the 26 Nosler should work well in a RUM action without much or any alteration.

Good quality brass, no belt. Great round.

If I was the OP, that’s what I would do.

DF

You're killing me guys, he wants my mag set up to stick to the Wby plan so I can build my 404 haha

His RUM would be an ideal donor for your .404J. I built one using a 300 RUM donor.

Maybe you should buy his RUM. He could buy a Wby 6.5-300.

DF

Ive already got an extra 375 M70 with nice wood, Sako is going to trade mags/followers after I sent him a pm about it. Ive already got a Lothar .423 bbl on hand that is really close to the M70 Safari contour. I have a custom 375 being put together now, so this gives my other gun a purpose! The LW bbl was going to become a 10.75x68 mauser, but its a bit heavy for that round imo. So, I'll order another .423 LW but in an Obendorf type contour, and stick the heavier one on the M70 and poof, new elephant gun!

FWIW My Montana 1999 in .300 RUM has a mag box that is a little longer than the M70. It can fit rounds up to 3.72 OAL in the magazine. And some models are available in the 26 Nosler

I like a full mag length box for the 26 Nosler. I’ve discovered that I get better accuracy at factory COAL of around 3.4”, more jump for the 120 TTSX and 120 E-Tips that I like to use.

DF