Gentlemen I am seriously thinking about another project for myself these days. The caliber in question would be a 6.5/STW, that I can use on big game and still shoot long range targets as well for kicks.

Anybody have any information on this particular wildcat? Your words of information and wisdom would certainly be appreciated immensely thank you. :)

I don't have any particular load info, but seems like it would be identical to the 6.5-300 Wby Mag. I've got a wildcat cartridge book around someplace that has the Wby version. I can dig it up for you, if interested. My reasoning: isn't the STW case an improved full length 300 H&H? That is the 300 Wby.

I don't have any particular load info, but seems like it would be identical to the 6.5-300 Wby Mag. I've got a wildcat cartridge book around someplace that has the Wby version. I can dig it up for you, if interested. My reasoning: isn't the STW case an improved full length 300 H&H? That is the 300 Wby.
Yep I believe you are right and specifically an 8mm mag if I am not mistaken. One of my old gun rag/mags has a great write up in it up the 6.5 STW.....see if I can't find.

From what i have heard the 7mmstw is eating barrels up pretty fast as it is ! So a 6.5stw should eat the bore even faster ! I don't know if stainless steel barrels will help for many more rounds then ChromeMoly ! JAGG

Great cartridge, Would expect that you will get at least a hundred rounds thru it before accuracy starts falling off because of bore wear. You might want to build it on a Savage action as that is the easiest to replace barrels on.

With the heaviest match bullets it should be a good 1000 yard match gun.

2Bits,

I've got a Ruger Number One in 25-06 that sees only occasional use. I've considered the .257 STW as an alternative. So many toys.....so little time! :)

Lobo in West Virginia

El Lobo I'm not sure if a 257 STW would fit in your action. The STW case began life as a full length 375 H&H before being made into the 8mm Rem mag. You would need the Ruger action chambered for the 375 length case to chamber a 257 STW.

I may be wrong about this so don't take it as gospel, but you might want to do some research on it.

Bob,

My Ruger rifle is their single shot version. It will take any length cartridge, as the gunsmith just reams out a little more of the bore to accomodate what ever case is being used. I could use a 3 1/4 inch .45 basic case un-altered and have a "Super 45-70".

Lobo in West Virginia

I would go with the 257 weatherby mag. first ! Then when you ware out that throat you can rechamber to the longer case ! The Weatherby is a good round as is !JAGG

Alyeska338....Yes sir, I would like to see that information if you can find it to send.

l had a 7mmSTW and put over a 1000 rounds through it before I got rid of the rifle. I know a fellow who purchased it from the gun store and he says he has shot over 400 rounds through it so far and still it shoots under .750 MOA with his loads.

Surely I would get more than a 100 rounds down the barrel before accuracy fell off!

I like what a 6.5 bullet can do on big game animals and at the long range targets. This is my reason mostly for wanting something that will not break my shoulder in the process while sitting at the bench.

I also have a couple of 25-06's but they are NOT in the same boat as this caliber and I do like that 140 grain bullet the 6.5 serves up for big game.

Thanks to you all gentlemen!
2Bits.

2Bits,
The article was written by Earl Etter, I'm not sure of the original publish date, but is in Wildcat Cartridges II from Wolfe Publishing 1992. http://www.riflemagazine.com/catalog/detail.cfm?ProductID=92 see the review in the Book forum here at Beartooth!

This was originally known as the 6.5-300 WWH or the 6.5-300 Weatherby-Wright-Holder. It burst upon the 1,000 yard benchrest scene in the early 1960's. Essentially, according to Etter, it is a 300 Weatherby necked down to 6.5 caliber, with no other changes. Seems it was quite popular in Pennsylvania for a while because of the late Al Hoyer, a custom gunsmith in Mifflintown, adopted it as his pet and turned out some real long range shooters based on this wildcat.

Case forming is done by running 300 Wby cases through a 6.5-300 Wby die from RCBS (Bonanza offered a die also, but I don't know if they still do). Another way would be to fireform 300 H&H or 375 H&H brass, which Mr. Etter preferred because the 300 H&H brass evidently had a thicker web. He also prefered to size down in steps, first to 7mm, then 270, then to 6.5.

At the time of publishing, the author used H870 and H570 exclusively. He had 2 rifles chrono'ed, one with a 30" barrel and the other with a 26" barrel.

He was able to push 139 grain Norma bullets to around 3300 fps with both barrels. Velocity for the same load, same bullet weight differed about 36 fps when shot from the 30" barrel and 26" barrel. I can't see that the extra 4" of barrel length would be justified if you could get an additional 36 fps (3309 fps vs. 3273 fps). He did get 3400 fps from the 26" barrel using 86 grains of H870. Rate of twist was 1 in 8" for the 139 and 140 grain bullets, which the author tested.

Apparently tests run at Hodgdon (reported by Ackley's Handbook for Shooters and Reloaders) indicated that the 6.5-300 WWH was not overbore, but was an absolute maximum case capacity for the 6.5 bore. That was with H870 and H570 powders. I'm sure with today's powders, velocity and barrel life could be improved upon. The author reported 4,000 shots from single barrels.

The author did report at the time that the cartridge was a one powder-two bullet cartridge and he would likely not build one for long range bench tournaments again because of that. With the slower burning new powders today, I think that would be less of a concern.

He also had killing problems with the cartridge due to bullet failure when pushed as fast as the 6.5-300 WWH would push them. Again, with today's bullet technology, I would think that would be less of a concern.

If you would like a scanned copy of the article, send me a PM with your email address. There is a ton more information in the article than I have put in this post.

Alyeska338.......Thanks for the information! I agree about that 4 inches of extra barrel too. I remember reading something about that particular "wildcat" from years ago, however I had forgotten about it really (like several dozen other things in the last couple of decades) I know that was well before I had the conversion made of the .270/300Win mag. I soon found out It was NOT for Pdog towns out west. We gave it a try though that day. I fired over a 150 rounds from the bench with the 140 grain bullet. I was an accurate rifle, but the barrel was to heavy for use on mule deer etc.

Any way thanks again for looking up that information! I really appreciate the effort. I would like to make this a long range hunting rifle for smaller big game animals and playing around on the range a bit.

With the slow burning powders today like H1000, Retumbo and others, along with plenty of time between groups and shots, this cartridge might not be too bad. Mr. Etter did report he was still shooting small groups with his rifle out to 1000 yards after 1000 shots. He reported others getting 4000 shots from their barrels. I'm sure these were bull barrels though.

Barnes is making their 130 grain Triple Shok X bullet in .264" these days, which should prove to be quite the bullet for mule deer or elk.

Lost River Ballistics is making a 120 grain J36 bullet for the target crowd that should be good.

Of course, Nosler is making their Partition in 100, 125, and 140 grain weights in .264".

Oh, by the way, the title of the article in Wildcat Cartridges for this wildcat is "the 6.5-300 WWH" "A former fan of The Greatest Long Range Cartridge takes a critical look".

Seems the only gripes he had about the cartridge was the fact that H870 was the only powder available at the time of writing that he could use to the cartridge's potential, and the 139 grain Norma and 140 grain Speer bullets were the only bullets available.

Sounds like it might be an interesting project.

The cartridge specs in the article was COAL of 3.755". Rim diameter of .530". Case length of 2.815" and outside neck diameter of .295".