Can a Classic Win 7mm be rechambered to this round?What about 7mm Ultra Mag?What about cost?The gun is currently a 7mm Rem Mag.

Thanks in advance.

Short answer: Yes. But there are a few things to consider. The action is long enough. It will take a full length H&H case, same length as the 7mmSTW.

You will need a new mag box and follower. I'm not sure about the availablity of these items now that USRAC went under. Your 7mm RM box has a spacer in it and the STW case won't fit lengthwise.

If you look carefully at the dimensions of the 7mm RM vs the STW, you will notice that at the position of the shoulder on the 7mm RM the diameter is a few thousands larger the the same position (measuring from the cartridge base) than the 7mm STW. With a simple rechamber, you may end up with a ring in the chamber where the 7mm RM shoulder was. This happened to me. You may have to cut off the threads and set barrel back to fully clean up the chamber. You will loose about 1" of barrel doing this and the 7mm STW needs all the barrel length you can stand to take full advantage of the larger capacity of slow burring powders.

When Winchester built 7mm STWs on the Classic M70, they uses the "Express" action. It is really the same as the M70 long action used for 7mm RM and similar length cartidges except that the loading port is opened up in the rear to make cartridge loading and ejecting easier. A shorter ejector and bolt stop is also used. A little over 1/4" is removed from the front of the rear receiver bridge and that also removes the forward scope base mounting hole on the rear receiver bridge. A new hole needs to be drilled. When you look at scope bases they list .860 spacing for M70 long actions and .330 spacing for express actions. If you to modify the rear receiver bridge, you will need new scope bases.

You can be by without opening up the rear receiver bridge, but you will have to replace or shorten the bolt stop. If you don't you won't be able to pull the bolt back far enough to pick up the cartridges from the magazine. Also, loading cartidges into the magazine will be more difficult with out opening up the loading ports. The is also the possibility of ejection problems.

All of this applies equally to the 7mm RUM except the part about the chamber dimensions. You will not need to set the barrel back for the RUM cartidge. But with the RUM, because of the larger case diameter, you may need to have some work done to the actions magazine rails to make it feed reliably.

quote:

Can a Classic Win 7mm be rechambered to this round?What about 7mm Ultra Mag?What about cost?The gun is currently a 7mm Rem Mag.

I've converted close to 10 M70 7rm to 7STW. about half I just took out the spacer and ground off the bolt stop and ejector. The others I bought a new box, stop & ejector. Either will work. If you grind the off use the spacer as your guide.

Now the ring issue is interesting. Looking at shoulder Dia listed in my loading book and plotting it out I still get the STW is .002" larger in dia at the old 7rm shoulder point.

However looking at the Clymer site they show the 7rm shoulder at .492 and the 7STW to be .491. Checking my fired, resized and reloaded brass I read .491. That would make the STW .006 larger at the 7rm shoulder.

I have never had a line but not saying it couldn't happen.