Can this be done? The 7mm RM brass is shorter than the 270 WBM, will the brass lengthen when necked down? What tools will I need or is there a better cartridge to form the 270 WBM from?

I used to shoot a 270 Wby quite a bit and I did for a while use 7 rem cases. I just ran them thru the resizer and let er rip.

It worked just fine.

Dogz

This came up on another forum a few yrs back, and a jillion people said it would work, I couldnt make it happen, I couldnt get the bolt to close. I don't have a book handy but I think there is about slight diff in belt size or case head size, heck i can't remember other than I couldnt make it work and I had a ton of 7 mag brass that I wanted to use.

QR,

If you run the 7mm Rem Mag brass throught a 270 Wby full length sizing die set to fully size the case they should work fine.

Its the shoulder on the 7mm Rem Mag that is to far forward and hit the chamber tht prevents chambering unless the brass is fully sized.

Other then that, just check to make sure you have enough neck release and you may have to adjust your loads as the REm Mag brass will more then likely be different then the Wby hulls.

Good Shooting!!!

50

Gringo--It's possible that if that was some once fired brass that you were in need of the "magnum" sizing die. No one seems to think these are necessary--they are a full length collet die that sizes right down to the belt. No other brand of dies gets right down to the belt--they all stop just a few .001" short and when you take brass from one gun and size it for another you can get a very slight bulge just ahead of the belt. A friend gave me hundreds of once fired 300 wby brass and I was going to use them in my 300 wby and 340 wby. (He owns about 4 different 300 wby's. About 1/2 of that brass would not go unless I ran them through this collet die. If you consider that weatherby brass is worth about $1.00 ea. I've paid for that die real fast. The die isn't cheap--about $90.00 but I can now make anything work with anything cause I can take the full dimensions back to factory.

Guys thanks for the information. A couple more questions. Should the neck be inside reamed or outside turned? Would a starting load for the 270 WBM be OK for the first fire forming?

I made lots of 270 wby brass from remington 7mmwby brass when it was available. You don't have to ream the case necks at all for a factory rifle. Your idea of using starting loads IS a good idea though. Rem brass is usually quite a bit thicker than wby brass. I had to drop 2 grains off the loads I was using and I then was getting the same velocity as I had before. A chrony is very useful when you start playing the brass "swapping" game!!

Kraky,

I didn't think about using a collet die, didn't mater, didnt have one in that cal anyway. I just full length sized them with reg sizing die. If I remember correctly it got tight right before it got to the belt. So I put my 7 mag back together and loaded 7 mag.

The magnum die isn't really a collet die like a lee collet die. It's a full length collet die that takes the whole body back to factory dimensions right down to the belt. People don't think they are necessary because not alot of people own more that one gun in the same belted mag caliber. BUT if you take brass from one gun with a slightly loose chamber and then size it and try and get it into a gun with a tight chamber you will see and have the problem. I fiddled and fiddled with that guys brass and was sure that my problem was not getting the shoulder "knocked back" far enough because to me I thought a normal full length die DID size all the way to the belt. Just another one of the things you learn after about 2-3 hours of scratching your head!!

It will work, but keep in mind that as the brass is shorter than factory WBY stuff, part of the chamber is unprotected. As a result a hard carbon (I think carbon) deposit can build up at the front of the chamber, making it difficult to use factory length brass after that.

For the 100 or so brass you need for a Wby cartridge, I'd spring for the higher cost Norma brass. At least that's what I did recently in a Ruger #1 270 Wby I had made. Recent Norma stuff is hard and works well.

RickF,

I agree, I bought Norma brass, a hundred will last me a long time.

QR,

There will probably be no reason for reaming or turning but as a gunsmith, I must advise people to check this critical dimension whenever necking down a case from one caliber to another.

Granted, there is only 0.007" difference between the two but this area need to have attention paid to it whenever non standard brass is formed for a different use.

If you have to do either, I recommend both at the same time. The reamer will remove any donut that forms at the base of the neck on the inside of the case and the turning will true the outside of the case.

As far as starting loads, just start with the standard 10% less then listed max loads for the 270 Wby and you will be fine.

There will not be a huge difference in case capacity using 7mm Rem Mag Brass but better be safe then sorry.

Like has been said earlier, a chorography is invaluable for this type of work.

Good SHooting!!!

50

Thanks for the advice guys. It looks like the Norma brass is the most economical considering the issues of forming the 7mm RemMag brass and short length. Now if I could find some of the Rem. brass produced for the 7mm WBM that seems to be a better fit.

I have a good quantity of The Remington new unprimed 7mm Weatherby brass on hand. E-mail me at cliogunshop@graceba.net and we can negotiate. Jerry