Has anyone tried this? Are dies available? Could you manufacture brasss by using a 270 WSM Full Length die and then neck sizing to 6.5?

Being that it's been a couple of years now. Yep, it's most likely been done. RCBSs online shopping is closed today. But try it tomorrow under custom dies.
FWIW, Motana Rifle Company chambers the 6.5-300 WSM.
http://www.montanarifleman.com/barreltechinfo.htm

My hunting buddy and I both have 6.5 WSMs. They hold more powder than the 6.5 Rem Mag, but less than the .264 Win Mag. Great performers. The SAUM case would hold a touch more powder than the 6.5Rem Mag, but not enough I would think for the extra trouble. In fact, if I were doing it over again, even though I love my 6.5WSM, I might go for the 6.5 Rem Mag.

I did mine on a Mod 7 with a Shilen SS barrel 1-10 twist. It easily meets or beats my 264 Win Mag with a shorter [22 1/2"] barrel and a bit less recoil. Accuracy is great. I found Benchmark and Ramshot to give the best vel/accuracy. Nice light Elk Deer rifle. I make all my brass from the 7mm SAUM brass with no trouble. i got my dies from CH/4D Custom dies for about 65.00.

Aloha, Mark

1-10" twist is a little slow for 6.5mm dont ya think?

I am hoping to develop a good longrange hunting load.

Bullets
130 SC-II
130 ACB
140 SGK
140 Partition
120 TTSX

I wanted to try 140 Berger VLD (unobtainium )

The most accurate load thus far has been:

Barnes TTSX 120gr boattail
(2.24 ogive seating) (2,79 COL)
(the leade is short(.17) and the overall mag length is as well)
Hodgdon H-1000, 62.5gr
CCI BR-2 primer,
REM case trim 2,030, flash uniformed, neck turned
Avg fps 3150 group .540


(I was Hoping for faster )

Powders thus far have been
Re-22
4831SC
4350
H-1000

I am considering RE-25 and Ramshot Magnum, Retumbo, US869 etc.

I would appreciate any words of wisdom on projectile and powder choices

I built a long range prone gun in it and it is a good cartridge. Shoots great. I used a 8.5 inch twist Kreiger barrel to use the bigger bullets. Found powder capacity was really all I needed in a 6.5. Had to use really slow burners like Retumbo and 5010. With a 29 inch barrel have gotten 3300 fps out of a 142 MK. My friends that shot with me named it the laser beam because it shot so flat. Toyed with the idea of building a hunting rifle in this caliber but found I can do all I want with a 260AI.

Sam

Thanks Sam,

How much Retumbo could yours digest without showing pressure signs?

DuggaboyaBoye,

About 62 grains of Retumbo was max in my gun. Went to 67 grains of WC872 which was a good load. Velocity with a 142 MK around 3050 fps. Any loads over 3150 fps were pushing pressure limit and brass life was short. With lighter bullets this cartridge would scream.
By the way my dies came from Redding.

Sam

I choose the 1-10 twist to keep rotational drag and pressures down and have found over 30 years with the 6.5s that HUNTING accuracy is not affected enough to worry about with the slightly slower twist. It also seems to make for cleaner kills too as the bullet isn`t trying to come apart at 300,000 rpm. As I generally use the 129 Hornady or the 140 Sierra Gameking for domestic hunting this is good for me. Accuracy has alway been an acceptable 1.0- at 200 but not at 100 yds always. I guess if I were a target shooter I would probably go for a quicker twist like the 1-9 or faster.
Aloha, Mark

Good to see you still around Mark

Bohica,

What powders and amounts did your rifle prefer?