With a quick change barrel ?

Can you use the same bolt ?


Simply swap out the barrels ?

300 WM = .513 case head diam

300 RUM = .550 case head diam

So, no.

you can run a switch barrel it would have to be 300wsm and 300rum, which would be cool because you would have tons of room to seat the heavy bullets in the 300wsm.

I think you are wrong, the RUM is a rebated rim at .539, the Win Mag is .532, sounds like it would work to me.

Just measured some of my 300 Rum brass. They are:

.526
.525
.526
.527
.528
.526

All measured at two places on the rim. Donald

They both use the same bolt head the standard magnum boltface. I have run a 338-300 Ultramag improved on a standard Magnum bolt. As stated the rims are rebated. If someone asks a question it is wise to actualy knoe the answer before telling them the wrong answer.

+1 it is a magnum bolt face, the .338 Lapua uses a bigger bolt face. So a 300 RUM, 300 Win Mag, 300 WSM, and 7mm WSM all use the same size bolt face. All can be built from a 300 RUM, someone you wanted to.

Apparently the manual that I referenced that data from isn't correct. It seemed funny that 513 was listed as the head size since I thought 532 was a standard belted mag...

All mine are .542 read just in front of the rim on the body. All mine have been fired and I don't resize anything but the necks so the case is chamber expanded. I don't have a piece of new brass or I would measure that but I don't think my cases have grown .030 in width from shooting. I should measure a new one some time to get a base line so I know the chamber size. Point is I don't think the brass was .513 when new as the rim is bigger than that and the rim is rebated so the case body would have to be bigger than .526 to start with. Donald

In short, yes.

Yes they are the same size.

What's the COL of a .338 Edge? That would be a cool way to get .338 Lapua performance out of a .300 Win mag action and bolt face. With a new tube and all it would also have to be a single shot I think. Do you think a Badger bottom metal for .338 Lapua would solve that?

my coal length on my 338 edge with 300smk is 3.85" I have a single shot so mag isn't an issue but even if you need a mag box wyatts makes one for $25 that is 3.9" long.

it will work as long as you use the RUM bolt face.i've done it.
using a sako extractor.
the only problem i had was ejecting a loaded 300 win.the extractor sometimes wouldn't quite have enough tension to grab and completely eject a loaded round. other then that it worked fine.
boltfaces almost identical.

I want to do the same using a win M70 LA action and magnum bolt.. probably have to wait awhile to start that project though.