Home Forums Hunting & Shooting Ask The Gunwriters .300 WSM vs. .300 Win Mag

The 300 WSM was never intended to compete with the 300 WM. It was initially called the 300 Jamison before Winchester stole the idea and hung the "magnum" label on it. This probably hurt the chances of success because people keep comparing it to 300 WM.

It is a good round giving 150-300 fps more speed (depending on bullet weight) than a 30-06 from a lighter more compact short action rifle. With the hotter loads it will somewhat overlap lower end 300 WM loads, but with the best loads is always 50-100 fps slower. The 300 WSM works very well with shorter 22-24" barrels whereas the 300 WM really needs 26".

In equal weight rifles recoil is almost exactly 1/2 way between 30-06 and 300 WM due to 50-100 fps less speed and about 10-12 gr less powder than 300 WM. Or you can shoot a 300 WSM in a 1/2 lb lighter rifle and get about the same recoil as 300 WM.

For someone putting together a lightweight mountain rifle and wanting more punch than 30-06 with manageable recoil it is a good choice. If you want that last 100 fps and don't mind more recoil or a longer heavier rifle any of the other 300 magnums will out perform it.

You guys have me halfway convinced to take one of my 06s on my elk hunt!

You guys have me halfway convinced to take one of my 06s on my elk hunt!

Do it!

That about describes it.

Says a NM farmer that uses a 460 Weatherby for rabbit.

JMR40,

Yes, the .300 WSM was indeed intended to compete with the .300 Winchester Magnum. Rich Jamison may never have seen it that way (I'm not going to go back and reread his articles on it), but Winchester did. Their advertising/publicity campaign constantly emphasized how the .300 WSM matched factory 180-grain .300 Winchester Magnum muzzle velocity through some magic in the case shape that allowed "more efficient" use of the powder. But the fact that the standard SAAMI muzzle velocity for 180's in the .300 Winchester Magnum was only 2960 fps, well under the capabilities of the round, was never mentioned.

And no, the .300 Winchester Magnum does not "need" a 26-inch barrel. With a 24" barrel it beats the top loads in the .300 WSM by around 150 fps (not 50-100), with both using 24" barrels. Both rounds will lose or gain just as much velocity from the use of a shorter or longer barrel.

The average "short" action for any rifle the .300 WSM is offered in weighs 3-4 ounces less than one of the same model of "long" actions used in .30-06's and .300 Winchester Magnums. The ONLY meaningful weight savings in a .300 WSM is due to using lighter stocks and/or barrels. The difference in action lengths runs .5 to .8 inch, depending on the action, which makes about as much difference in "handling" quality as using Weaver scope mounts instead of Leupolds.

It's easy to buy or build any of the three in a rifle weighing the same, and with factory 180-grain ammo the recoil of the .300 WSM is far closer to the .300 Winchester Magnum than it is to the .30-06. In 8-pound rifles, Sierra's recoil computer recoil calculator puts it at 22.9 foot-pounds for the .30-06, 31.1 for the .300 WSM, and 34.8 for the .300 Winchester Magnum. Now, we can manipulate rifle weight and handload numbers all we want, but those are the facts with 180-grain factory ammo in rifles of equal weight.

Part of the reason I know all this is because I've owned and handloaded for several rifles in each chambering, and hunted big game from "deer-sized" up through 6x6 elk with all three cartridges. I still own rifles in all three right now, and may (or may not) hunt with all of them this fall.

I am NOT anti-.300 WSM, but the claims Winchester made in the beginning about the magic case shape and less recoil were ballistic BS. The .300 WSM gets exactly what it should from it's case capacity, nothing more, and if somebody wants a slightly milder .300 magnum then it's certainly a cartridge to consider--as is the .300 H&H.

JMR40,

Yes, the .300 WSM was indeed intended to compete with the .300 Winchester Magnum. Rich Jamison may never have seen it that way (I'm not going to go back and reread his articles on it), but Winchester did. Their advertising/publicity campaign constantly emphasized how the .300 WSM matched factory 180-grain .300 Winchester Magnum muzzle velocity through some magic in the case shape that allowed "more efficient" use of the powder. But the fact that the standard SAAMI muzzle velocity for 180's in the .300 Winchester Magnum was only 2960 fps, well under the capabilities of the round, was never mentioned.

And no, the .300 Winchester Magnum does not "need" a 26-inch barrel. With a 24" barrel it beats the top loads in the .300 WSM by around 150 fps (not 50-100), with both using 24" barrels. Both rounds will lose or gain just as much velocity from the use of a shorter or longer barrel.

The average "short" action for any rifle the .300 WSM is offered in weighs 3-4 ounces less than one of the same model of "long" actions used in .30-06's and .300 Winchester Magnums. The ONLY meaningful weight savings in a .300 WSM is due to using lighter stocks and/or barrels. The difference in action lengths runs .5 to .8 inch, depending on the action, which makes about as much difference in "handling" quality as using Weaver scope mounts instead of Leupolds.

It's easy to buy or build any of the three in a rifle weighing the same, and with factory 180-grain ammo the recoil of the .300 WSM is far closer to the .300 Winchester Magnum than it is to the .30-06. In 8-pound rifles, Sierra's recoil computer recoil calculator puts it at 22.9 foot-pounds for the .30-06, 31.1 for the .300 WSM, and 34.8 for the .300 Winchester Magnum. Now, we can manipulate rifle weight and handload numbers all we want, but those are the facts with 180-grain factory ammo in rifles of equal weight.

Part of the reason I know all this is because I've owned and handloaded for several rifles in each chambering, and hunted big game from "deer-sized" up through 6x6 elk with all three cartridges. I still own rifles in all three right now, and may (or may not) hunt with all of them this fall.

I am NOT anti-.300 WSM, but the claims Winchester made in the beginning about the magic case shape and less recoil were ballistic BS. The .300 WSM gets exactly what it should from it's case capacity, nothing more, and if somebody wants a slightly milder .300 magnum then it's certainly a cartridge to consider--as is the .300 H&H.

For me it would boil down to the rifles, i.e. which one I liked the best.

A 180 gr bullet at 3000 fps is what it is,no matter what case you use to get it there.

Jeff,

Where did I say anything about either cartridge "needing" a 26" barrel? Some other people posted about 26" barrels on the .300 Winchester, but I sure didn't.

You might want to check back in this thread a little ways for another of my posts listing the velocities of 180-grain bullets from a 24" barrel in the .300 Winchester with some powders introduced in the last 12-15 years.

Some short actions are much shorter than the same "long" action, because the long action is enough longer to handle cartridges like the .300 Weatherby and .375 H&H. But others are just long enough to handle the .30-06 or .300 Winchester Magnum. I'd bet that if blindfolded you couldn't tell the difference in "balance" between a couple of rifles using the latter sort of actions. This is because I've invited some people to try with NULA rifles.

Not to detour here but to pick up on Win's "smoke 'n mirrors" marketing of the WSMs, I remember a poster showing the 270 WSM equaling the 270 Wby, the former with some
streamlined bullet and the latter with some truncated pill. 🤔 IIRC, the point was that at 400 yards there trajectory was the same. 🙄

The .300 WSM gets exactly what it should from it's case capacity, nothing more...

Do it!