6.5 WSSM

[RiverRat]

I have a 6.5 mm barrel to experiment with and I am really thinking hard about necking the 243 WSSM up to 6.5 when the brass becomes available for a 600 and 1000 yard F class rifle. What are some you fellow forum members thoughts on that. I am thinking velocity should be about the same as a 6.5 X 55 Sweede or a little better with a 140 class match bullet.

Shoot Safe, Shoot Straight.....RiverRat

 

[baldeagle713]

Hmmm interesting.
I know that the 6.5 WSM can work. Seen it. barowed a rifle chambered in it and shot it. Shot like a laser!
Now 6.5 WSSM! HMMMMMMM! let me know.

 

[Mysticplayer]

Performance for the 6.5 WSSM should be similar to the 6.5-284Win. Case size is very similar. This would surely test the benefits of a short fat case.

Would consider improving the shoulder to 35 to 40deg. Helps with case stretching and will give a little bit more case capacity.

With a little development, should be every bit as good as other 6.5 cartridges.

My present toy is a 6.5 based on a '08 case. Imagine a "short" 30 Gibbs. Should be forming brass today. Need my throating reamer to show up to do final fitting. Hope to get 2900fps+ with 140gr bullets.

Let us know how it turns out...
Jerry

 

[bgordon]

Great minds must think alike cause that was my first thought when I saw the pictures of the WSSM in a gun magazine.

Also, I have an extra 6.5mm target barrel blank sitting around but don't have a short action magnum bolt face sitting around to finish up such a project.

Do you think a regular short action would be suitable, or are you intending to buy one of the factory WSSM rifles to rebarrel?

 

[RiverRat]

Jerry:
I have thought about necking that case on up to 30. GEZZZZZZZ I think that would be a shooter. Velocity should be in the 308 range or better I would think. Good luck with your present project. I am a big fan of the 260, but I know I can't get 2900 fps accurate velocity out of a 260, you have my interest with that project. Initially I am going to just neck up the 243 WSSM to 6.5 without further modifications to see what it will do. The 35 degree shoulder maybe next depending on what happens with the first experiment.

Bruce:
I have a Remington short action that I had opened up to build a 300 WSM on and I am thinking it would be very suitable. The bolt face is perfect and it has been blue printed. I am thinking it would work through the magaizine even when throated long making it a good long range varmint cartridge if that was on the agenda. I would bet the WSSM aciton would not feed a long throated 6.5mm. The 300 WSM barrel that is on this action now is nearing its last legs with 1300+ rounds on it. So I am going to build it on that action. If it shows promise with that barrel I had given to me, I will order a barrel and chamber a fresh barrel on it. IF I didn't have that action with the proper bolt face, there is no doubt in my mind I would wait for Wincherster, not Browning to come out with the WSSM sized action.

When the 243 WSSM ammo comes out I am going to buy a box of it pull the bullets and neck up to 6.5, do the rest of the case prep work and seat a bullet to .100" more than full neck tension with a 140 Berger and have the reamer ground so the bullet just touches the lands at that lenght. I am thinking seat it just a little deeper than full neck tension so I have a some room to chase the lands and still have full neck tension.

Buddy, send me an email the last one I sent to you got returned as undeliverable. This is Gary from southwest Indiana, maybe you don't recognize me as RiverRat.

 

[dwm]

How much smaller is a 243 WSSM than a 7 MM SAUM case?

I have a 7 MM SAUM that I have been thinking about necking down to 6.5, to make a 6.5 SAUM.

Or maybe even a 25 cal SAUM/WSSM.

Doug

 

[bgordon]

Riverrat,
I did know it was you posting but did not know that your 300 WSM barrel is giving up the ghost.
My e-mail here at work is still giving me fits, so sometimes it takes several tries for something to get thru.

The big concern I have with the WSSM brass is quality. You know what I am talking about. Early on people were griping about the quality of the WSM brass, but that seems to have gone away lately. Perhaps the brass forming process is smoothed out enough to get the quality up to the standards of us f-class shooters.
If I do a 6.5 WSSM, it will specifically be designed around the 123 Scenar simply because I have had such phenomenal luck from that bullet. No reason to change what ain't broke. My only other concern has to do with powder choice. I don't know enough about the situation to know which powder is going to be correct. My preference is to stay with Reloader 19 cause it has been a winner in the past. What powders are you considering?

 

[RiverRat]

dwm:
I truly don't know how much smaller a 243 WSSM case is than a 7 SAUM is. If I had to take a GUESS and that is all it would be. I would GUESS 15 to 18 gr. difference.

 

[RiverRat]

Bruce, I am willing to bet that the WSSM brass will be just as bad as the 300 WSM brass that I delt with. I have heard that the Winchester WSM brass is getting better, but I am sure it will not be in the same class of the Norma 300 WSM brass I am now shooting. If I buy 300 pieces and do the sorting and preping I will come up with enough good pieces to wring out the 6.5 WSSM.

With the take off barrel that has a little over 400 rounds on it I can get into this project pretty cheap. And if it works, I should have only load tweaking to do with a new barrel, or at least know which direction to go which saves a lot of money and barrel wear. And if it dont work well, I can tell other shooters been there did that, and it didn't work for me. Maybe save some body else the time, trouble, money, and aggravation. There is something positive in everything.

As for powders, I am going to use the 4350 class of powders for the 123 and the 4831 class of powders for the 140 class bullets. GEZZZZZZZZ that is the fun, seeing what works with a new chambering.

The accuracy is certainly still there with the 300 WSM but it is copper fouling pretty bad in the throat area now. But it did shoot superbly in the July match that I shot in. It shot a 598-27X agg. I am going to shoot the 300 WSM in the August match in Tennesse, the September match in Tennesse, and the October match at the local club and then tear it down to start development on the 6.5 WSSM. When I start working with it I will keep you posted as to the progress or lack there of depending on which way it goes.