This whole WSM evolution appears to be simply Winchester engineers copying Rick Jamisons pet cartridge. Has anyone seen or heard anyone giving any credit to Jamison? What do you think?

The 300 Jamison is nothing like the new short action magnums. The Jamison is a full length belted magnum designed from an improved 8mm Remington magnum case.

From one Dan to another Dan, think you are wrong buddy. Don't read Shooting Times much anymore but Ricks .300 was based on a .404 Jeffery case, cut to 2.5 inches and fireformed. Or maybe I'm just a dope.

This has been hashed and rehashed a few times.

Dan, you're correct!!!! The Jamisons are a shortened and formed 404 Jeffrey. I have two of them. And one WSM.

Olin claimed the case was "new" and based on the 348 Winchester. It's not. The 348 is rimmed. While also short, about the only similarity is length and a similar head diameter. The WSM follows closely the head dimensions of the Ultra Mags which followed the Canadian Mags, which were derived from the 404 Jeffrey. The WSM's have some diminsions which are beyond the .010" tolerances in SAAMI specifications. That apparently avoided copyright conflicts with the Jamisons. The word was that Jamison tried to sell his case to Olin who liked it. His ego insisted on the cartridge bearing his name, which never happens when wildcats go legitimate. Olin designed a case with enough minor changes to get around all the problems and avoided payment and credit for it, and named it the WSM. It IS a new case.

The other thing lost in this is that Jamison's rounds were not new or original either. Gradle did them on the 348 case with the rim turned down in the 50's. Two local smith's here in my area did their's in the 1960's and 1980's... Dave Gentry's were done in the 80's on the 404 case to work in a 2.8" box... there's nothing new under the sun and I'm personally glad that Jamison didn't get credit as he NEVER gave credit.

Brad

Just for additional info, I believe the original Jamison cartridge was done on the 425 Westly Richards case (for the rebated rim, I think)but someone pointed out the advantages of using the 404 brass and so he went with that. - Dan

Gentlemen,
This is new info for me. I didn't know about the others before but I agree there isn't a lot that's really new. I just noticed that Layne Simpson necked down the 8mm RM and it was big news and then necked it up to .35 and now we have factory offered 7mm STW and .350 STA and he got credit. Others before him had done similar things. Rick shortend an existing cartridge and formed it to a short mag that works and there was no mention of him ( or his predecessors). Just a strange thing to watch. I was interested not for the .300 jamison but for the 6.5 or .257 possibilities.

No, there's little new out there. But some folks seem to get credit when others are overlooked. I for one was shocked when several magazines and reloading manuals credited Jim Carmichael with the .260. That little round was done MANY times before Jim ever barreled up for his .263. Nothing against Carmichael, but he just doesn't deserve to be credited for a wildcat cartridge that has been in existence (and widely used) for many years. Unfortunately, in the media, many times one simply rehashes what another says without the least bit of legitimate research.

Ah yes, you guys are correct, for some reason I was thinking of the 300 Jarrett.