Well, I guess what Im asking is this. If you were thinking about building a new project and wanted to pick between a 300 wsm an a 300 mag. Which would you pick and why.
I understand that the WSM is a different case, slightly more powerful. What are the advantages and disadvantages?
I think they are both great calibers but my choice would be the 300 wsm,it is a more efficient case and is a little less fussy to load for probably because of the case design also it is used in short actions and will have better velocities if you like shorter barrels.
Both good cartridges. I choose the .300WinMag. and have for the past 15 years. I had a 7mmRemMag for just as long. They are not fussy to load for, and I get .3" groups at 100yds and get under MOA out to 650yds with my .300 and average .2's (occassionally getting .1's) at 100yds with the 7mmRemMag. I average 3100fps with 180gn bullets (26" barrel) in a Savage 112BVSS and 3200+fps with the 150gn bullet (26" barrel) in a 700P.
I have never owned a .300WSM or 7WSM, but I have reloaded and done load development for a couple. I owned a .270WSM and it is a "true" magnum if you're comparing it to the .270Win. It bumps the .270 Weatherby.
In my experience the .300 and 7mm WSM's do not offer anything in the way of performance over the .300WinMag and 7mmRemMag. The "standard" length magnums have been around for 45 years and are still doing fine as far as I can see. The WSM's are newer mousetraps. JohnnyK.
"The only thing necessay for the triumph of evil is for good men to do nothing."
The Win mag will run the 220 gr bullets a little better than the 300 WSM.
Up to the 210s, they are ballistically the same. The WSM in long barrels will run the 210s to over 3000 fps in some 30" tubes. 2950 is the norm.
The 300 WSM will get 2-3x the barrel life of a Win Mag. We have documented 4000 rounds down a comp gun in WSM, while the same shooter never has got over 1300-1400 in his Win Mags. my first tube went over 2400 before I pulled it and it was just then starting to open up a little.
If you anneal we have gone over 35 reloadings on WSM brass.
So for a hunting or comp gun, go the 300 WSM for all the previous reasons and the barrel life.
the 7 WSM is another animal. Similar ballistics but a sure fire barrel burner.
Average life on the 7 WSM seems to be well under 1000 rounds down to as little as 600-700 in some cases.
280 AI and 7mm Mag seem to be the better choices.
If you learn how to properly size belted dies, no difference in case life if you anneal. If not, they will be improperly head spaced and come apart. Simple as that.