Here goes for my first post on this forum.

I am having problems sourcing brass for my 7mm wsm, can I neck size and fireform 300wsm brass without too much trouble. or is it best to just wait untill I can get 7mm wsm brass.

thanks in advance


Murph

Murph;
I would suggest that with so much power in such a small package I wouldn't take the chance!

I'd wait for the 7mm WSM brass!

WELCOME TO THE AR BULLETIN BOARDS!
Lots of good advice gets posted here!

The answer is; "Yes you can, but!". The necks will thicken, perhaps to the point you might have to turn or ream them. Necking down from 308 to 284 isn't much and the way some chambers are cut, you might wind up with the necks fitting just fine. Have you checked Cabela's, MidwayUSA, Graf & Sons or Widener's for the brass?

Graf says they have it. http://www.grafs.com/metallic/729

Cabela's says they have it. http://www.cabelas.com/cabelas/en/templates/product/sta...=cat20843&hasJS=true

Losk Stock and Barrel says they have it too.
http://www.lockstock.com/prodinfo.asp?number=WBR7WSM

Smedley

Reducing any .30 caliber brass to .284 is typically a one-shot run through the FL die. There is no reason that the WSM series should be any different, even with their sharp shoulder. It is doubtful that any slight increase in neck thickness will do anything other than improve the chamber fit, and it is also doubtful that the neck will lengthen enough to require trimming.

Welcome to the forum!

Thanks for the very rapid replys guys

I am well aware that there are lots of suppliers who have stock in the States, unfortunately I am on the opposite side of the Atlantic in Bonnie Scotland. it would appear that 7mm wsm brass is like hens teeth here,but there are several suppliers here with 300wsm brass in stock, I thought that it would be a similar process to fire formimg for ackley improved cartridges .

again thanks

Murph

I decided that I would bite the bullet so to speak ,I got a bag of 300wsm brass and necked 6 of them down. I marked the neck with a felt marker pen, and just sized down far enough to leave the pen marks on the last portion of the neck above the shoulder. I reckoned this bump in the neck wouould be enough to give proper headspace. after checking each empty case would allow my bolt to close with slight resistance, I loaded them up with 57 grains of h4831 and 140 grain nosler bt's keeping them at max oal of 2.860. I have went out and fired these through my rifle and they were very soft shooting with little recoil. again I checked each case and there were no signs of excess pressure or that the case had stretched at the web. now that I have got back home I have compared the fire formed .300 cases with new ones and you can see the difference in the shoulders with the naked eye. so now I think I can continue and fire form the rest of the bag in the same way

Thanks again for the advice guys

All the best

Murph

The thing you have not considered is the 7mm wsm casing is slightly longer then the 300wsm.

quote:

Originally posted by Stonecreek:
Reducing any .30 caliber brass to .284 is typically a one-shot run through the FL die. There is no reason that the WSM series should be any different, even with their sharp shoulder. It is doubtful that any slight increase in neck thickness will do anything other than improve the chamber fit, and it is also doubtful that the neck will lengthen enough to require trimming.Welcome to the forum!

I'll second that. Who's buying this round? roger