The Firing Line Forums - View Single Post - What's the difference between 300 win mag and 300 weatherby Mag

U.L.Grant · September 21, 2012, 08:12 AM

QUOTE:
okiefarmer308
Member

Join Date: February 21, 2010
Location: SE Oklahoma
Posts: 20

300 mag short case
My first post here. A couple or 4 years back I was at a gun show and saw one of the prettiest custom stocked rifles ever. The guy said make me an offer,I popped off($200) and was the proud owner of a supposedly 300 win mag built on a 1917 Enfield action. Worse yet it was left handed stock,I can shoot either handed but am primarily right handed. Took it home prepared for mule like kicks. It did not kick as bad as many 30-06's I have shot. It is a very heavy stock,I will admit. After 3 shots I noticed the shoulders looked funny,yep it was stamped 300 win mag but is a 300 Weatherby magnum. It took a couple of trips to an old gunsmith that was sloooooow before it was figured out. Eddystone action so he magnifluxed it to be sure it was safe. My question is,I have a buttload of 300 win mag brass,would it be safe to fire form and just use them? I know the neck would be shorter but would it be feasible? END.

old question but hot topic lately, with the rising cost of 300 Weatherby ammo, and the economy the way it is

yes, if the necks dont' split upon fire forming, and you get a good neck-only resize die from Hornady, you can just resize the necks, reload them to Wby specs, and use them. The neck will just be shorter, that's all. It would help to soften the brass necks for longevity, by annealing them- but that goes for any 300 mag brass, HH Wby or Win Mag- the 300 belted mag family of cartridges is hard on brass to begin with, regardless of specific cartridge chambering.

Norma made a brass headstamped "300 Re Special" that was basically a generic brass 300 mag, with a 300 Win Mag shoulder, but 300 H&H and 300 Weatherby length. It can be fire formed to either 300 H&H or 300 Wby Mag. Or, it can be trimmed and used as 300 Win Mag.

what most don't realize, but is becoming evident now with the advent of the internet and message boards such as this, when you buy a 300 Wby Mag rifle, you really have in effect, a multi-cartridge firearm. It will fire 300 Win Mag, 300 H&H, or 300 Wby mag ammo. The only difference will be, the first 2 smaller magnums, will have slightly less velocity- and once that brass is fire formed to the 300 Wby mag, it will no longer fit in H&H or Win Mag chambers, unless it is resized back again in a full length sizing die.

The 300 Wby Mag will also chamber and fire 308 Norma Mag ammo, but at that point the brass is so short in the neck area, it would be useless for reloading, once fire formed to 300 Wby Mag.

the reason it's not popular to do is, less velocity, and it works the brass more, and less reloads from the brass. Most guys who buy a 300 Wby mag, do so for the ultra-high velocity. And one would look kind of silly loading up their Mark V 300 Wby Mag, from a box of new 300 Win Mag shells from Walmart for $25. So firing 300 Win Mag in a 300 Wby, sort of defeats the purpose.

It would be like putting a Chevy hood ornament, on the hood of a Cadillac. Sure it will bolt on, and it's still a GM, but it's not the right hood ornament.

but to anser your question, yes, you can re-use the Win Mag brass in the Wby Mag, as your findings showed, the neck is still long enough to seat a bullet. Norma knew that when they created the "300 Re special" brass.

September 21, 2012, 08:12 AM	#53
U.L.Grant Member Join Date: July 16, 2009 Posts: 16	QUOTE: okiefarmer308 Member Join Date: February 21, 2010 Location: SE Oklahoma Posts: 20 300 mag short case My first post here. A couple or 4 years back I was at a gun show and saw one of the prettiest custom stocked rifles ever. The guy said make me an offer,I popped off($200) and was the proud owner of a supposedly 300 win mag built on a 1917 Enfield action. Worse yet it was left handed stock,I can shoot either handed but am primarily right handed. Took it home prepared for mule like kicks. It did not kick as bad as many 30-06's I have shot. It is a very heavy stock,I will admit. After 3 shots I noticed the shoulders looked funny,yep it was stamped 300 win mag but is a 300 Weatherby magnum. It took a couple of trips to an old gunsmith that was sloooooow before it was figured out. Eddystone action so he magnifluxed it to be sure it was safe. My question is,I have a buttload of 300 win mag brass,would it be safe to fire form and just use them? I know the neck would be shorter but would it be feasible? END. old question but hot topic lately, with the rising cost of 300 Weatherby ammo, and the economy the way it is yes, if the necks dont' split upon fire forming, and you get a good neck-only resize die from Hornady, you can just resize the necks, reload them to Wby specs, and use them. The neck will just be shorter, that's all. It would help to soften the brass necks for longevity, by annealing them- but that goes for any 300 mag brass, HH Wby or Win Mag- the 300 belted mag family of cartridges is hard on brass to begin with, regardless of specific cartridge chambering. Norma made a brass headstamped "300 Re Special" that was basically a generic brass 300 mag, with a 300 Win Mag shoulder, but 300 H&H and 300 Weatherby length. It can be fire formed to either 300 H&H or 300 Wby Mag. Or, it can be trimmed and used as 300 Win Mag. what most don't realize, but is becoming evident now with the advent of the internet and message boards such as this, when you buy a 300 Wby Mag rifle, you really have in effect, a multi-cartridge firearm. It will fire 300 Win Mag, 300 H&H, or 300 Wby mag ammo. The only difference will be, the first 2 smaller magnums, will have slightly less velocity- and once that brass is fire formed to the 300 Wby mag, it will no longer fit in H&H or Win Mag chambers, unless it is resized back again in a full length sizing die. The 300 Wby Mag will also chamber and fire 308 Norma Mag ammo, but at that point the brass is so short in the neck area, it would be useless for reloading, once fire formed to 300 Wby Mag. the reason it's not popular to do is, less velocity, and it works the brass more, and less reloads from the brass. Most guys who buy a 300 Wby mag, do so for the ultra-high velocity. And one would look kind of silly loading up their Mark V 300 Wby Mag, from a box of new 300 Win Mag shells from Walmart for $25. So firing 300 Win Mag in a 300 Wby, sort of defeats the purpose. It would be like putting a Chevy hood ornament, on the hood of a Cadillac. Sure it will bolt on, and it's still a GM, but it's not the right hood ornament. but to anser your question, yes, you can re-use the Win Mag brass in the Wby Mag, as your findings showed, the neck is still long enough to seat a bullet. Norma knew that when they created the "300 Re special" brass. Last edited by U.L.Grant; September 21, 2012 at 12:59 PM.