on the verge of one...You are probably thinking why not use the WSM as a parent case in order to take advantage of the better Euro brass. Well, one reason is that I already own a nice 300 WSM and would like my first wildcat to have a different head stamp. Also, Longevitiy and market share aside if you look closely at the .30 cal test data in the Nosler#5 manual it appears that with their test barrels the SAUM was slightly more efficient than the WSM...if you were into hair splitting.
Considering using 6.5 Rem mag data for starting load development...Thoughts?

I shoot a 6.5 WSM and I thought I would share with you my experience due to the similarities.

My rifle is a customized Mod. 70 classic short action with a 24" Hart SS #4 barrel. One in eight twist.

I am using a load of 61 grains of Reloader 22 with 129 gr. Hornady's. Sub .5 MOA.I had Dave Kiff from Pacific Precision grind my reamer and that was before the .270 WSM or the 7mm WSM hit the market. For personal reasons I had Dave grind the neck to .296.

I am neck turning my brass. I am turning it to a wall thickness of .014. Thus, it is not a super tight neck.

I am starting with Winchester .30 WSM brass and I found it to have extremely consistent in weight.

I started with WW760 and found that my rig would not tolerate it; it tried to pressure up on me.

Herb Riley turned me onto to the 61g. of Reloader 22. I have not chronographed this load so my velocities are purely speculation. I would be dissapointed if they were below 3100 fps.

This rifle started it's life as a standard bolt face (i.e. .473) Model 70 Classic action. When converted to 6.5 WSM, the feed rails were altered. I have not had any feeding problems. Last fall, I had some Javalina's cross the sendero I was hunting on and was able to take three with as many shots and it was quick shooting. My point here is the action fed the shells perfectly. There are some on this board that would lead you to believe that the short fat magnums have feeding problems. I have experienced no feeding problems.

Best of luck to you!

Sounds to me like one heck of a lot of work
to get to 270 performance-grins, but it is a heck of a lot of fun isn't it! Or is it?

Nope I'd rather be on the hill.

"GET TO THE HILL"

Dog

I think R22 will work, but for top velocities, you might need R25. Heavier 6.5 bullets might even need H870. My 270 WSM needs R25 to reach 3150 fps with 150 grainers, so you may be in the same ball park with the 6.5MM 129s. I am about to try AAs Magpro, which was specifically designed for the WSMs. This might ba an excllent propellant for you to test.

Sabot and 30 Mag fan-

You are the only two guys I've never rapped with about the 6.5 shorties(unless you've changed your handles. I shoot a 6.5 WSM and used it fairly extensively last year. I am tinkering with it every week. I really feel the gun wasn't set up right as accuracy isn't what I've expected, but velocity is. I have a 1:9 twist 26" Lilja and used or used 140's. I cannot remember my RL-22 max with 140, but think it was around 57. I use RL-25 regularly with 140's and 60-61 is about right. I'd be interested in your load data if you want to swap.

I just loaded but haven't shot some 129s. Whack any critters with this load yet??? I thought the 140's were thin jacketed, may use these for yotes.

Jesse-

I forgot to mention, I am shooting Hornady 129 gr. BT spitzers ahead of the 61g. of Reloader 22.

The barrel is a 24 inch Hart #4 contour with 1 in 8 twist. I went with a faster twist because I wanted to eventually move up to the 140's. The last group I shot in it was .4 inches at 100 yards.

I ordered some Barnes XLC in 120 grains and if they shoot as good as they look they will be great.