Thread: .300 WSM variants

For those of you possessing a .300 WSM, you may be interested to know that wildcatters in the USA have produced the following variations:

.22-300 WSM: 4,100 fps velocity using a 50 grain Nosler projectile
6mm-.300 WSM: 3,180 with a 107 grain Sierra
6.5-.300 WSM: 3,030 with a 140 grain Sierra
7mm-.300 WSM: 2,850 with a 170 grain Norma
.338-.300 WSM: 2,550 with a 250 grain Speer.

I think there's a .277-300 WSM too does about 3,195 with 150gr Hornady

so..is that to get around the patent crap around anything 7mm??? the 7mmwsm had some sort of "thing" that made it expensive
there is a 270wsm already so is this the same or just renamed to get around patent???

7mm 300wsm was better than the 7mm wsm due to longer neck I believe.
My experience with wsm's is that they became problematic with bumping the shoulder back due to the shoulder angle. This may well of been related to the brand of brass I was using.

The wsm and wssm cases have been taken all the way up to 458 and even a straight wall 50 cal of some sort.
There was a 25 wssm at some stage. Neck up to 6.5 was also a nice concept for something that was a bit less of a barrel burner. The problem is finding brass to feed the thing.
If you have the money and the patience everything is possible I guess.

.35 Sambar
And .375-300wsm are a bit of a favourite one here. See some .325 wsm pop up for sale but that was a weird one for projectile choice. Didn’t make much sense as a factory offering when there so many more 338 choices


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Originally Posted by Micky Duck

so..is that to get around the patent crap around anything 7mm??? the 7mmwsm had some sort of "thing" that made it expensive
there is a 270wsm already so is this the same or just renamed to get around patent???

Greetings @Micky Duck,
There was a problem with patent infringement which I believe resulted in the lack of new medium size 7mm cartridges for about 20 years. The big two, Winchester and Remington thought they could get away with it but could not and sulked for a long period. The longer head to shoulder datum dimension with the 7mm WSM is to stop the 7mm WSM being chambered in a .270 WSM and blowing it up. Remington did the same thing with the .280 Rem to stop it being chambered in a .270 Win. Some manufacturers now seem to have got over their funk and we have the 7mm PRC although this is a longer case. We can also likely thank the debacle for the US manufacturers getting over their hatred of anything 6.5mm. The grandfather of the short fat cartridges was, from memory, a shortish cartridge based on the .348 Win case with the rim turned of and an extractor groove added in the 1950's, the same parent case the WSM's use.
Regards Grandpamac.

And to think that the WSM was designed, and made right here in NZ several years before Winchester introduced it. Was designed and made using the same principles as the PPC cartridges, short and fat. The guy who originally designed it was a very good friend of Graham Henry's, and Graham wrote an article about it, and how it performed. The first animal shot with the "300WSM" was a bull tahr shot in the Dobson.

Lazzeroni had developed its range of short magnums based on the lapua ( or Rigby) in the early 90’s. The foundations for the wsm range that came later was already laid
And let’s not forget the 6mm ppc of the 70’s which is the foundation for the short fat cartridges.

Originally Posted by Husky1600#2

And to think that the WSM was designed, and made right here in NZ several years before Winchester introduced it. Was designed and made using the same principles as the PPC cartridges, short and fat. The guy who originally designed it was a very good friend of Graham Henry's, and Graham wrote an article about it, and how it performed. The first animal shot with the "300WSM" was a bull tahr shot in the Dobson.

Mr Woodman, by any chance??

Originally Posted by Basenjiboy

Mr Woodman, by any chance??

Yup, certainly was.

Originally Posted by Husky1600#2

And to think that the WSM was designed, and made right here in NZ several years before Winchester introduced it. Was designed and made using the same principles as the PPC cartridges, short and fat. The guy who originally designed it was a very good friend of Graham Henry's, and Graham wrote an article about it, and how it performed. The first animal shot with the "300WSM" was a bull tahr shot in the Dobson.

Greetings,
I think we need to go back a lot further than that for the first of the Short Magnum cartridges. During the 1950's Roy Gradle introduced his 7mm Gradle Express. This was based on the .348 Win case as mentioned in my previous post, same case as the WSM cartridges. The case was around 2.230 inches long and the cartridge was a little longer than the WSM's overall. John Haviland wrote it up in Rifle Mag no 348 and compared its performance with the WSM, SAUM and Rem Mag in a period Enfield rifle. The rifle had its original 7/8" tube 2.5 power Lyman scope without adjustment s. The mount allowed for zeroing. John called it the first short magnum which is debatable but it was likely the first beltless short magnum.
Regards Grandpamac.