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Gentlemen, I am looking to build a 358 WSM. I am planning to use a Winchester M70, classic stainless that is now a 270 WSM and rebarrel it with a Pac-Nor #4, 1-12 twist. Does anybody know where I can find a reamer? I figure this has been around for a long time so somebody has to have one.... but, I don't know what to ask for. Is it technically called a 358 WSM or 35 WSM or 350-300 WSM or what.

Any info that you guys could give is greatly appreciated.
Thanks in advance,
Bob

I'm kind of a 35 caliber nut and first heard about it called a 35 Sambar. Here is the reamer for a 35/300 wsm

Was considering one some time back as I like compact powerful rifles. The Remington Model 7 looked good with a custom fullstock and19" barrel.

Why not have Pacnor chamber it? They did one for me, I'll check the barrel stamp and see what they called it.

IIRC, they stamped it as "358/300 WSM."

They list the chambering as 350-300 WSM on their website. They also list a 350 WSM, not sure what the difference is.

I have considered rechambering a 350 Mag to one of those, quite a while back. Never did. I’d be interested in hearing how it turns out v

Mine shot 225 grain partitions accurately at 2950 fps.

Smokepole, that is moving a 225 grain. First I have heard of a 35 WSM. May have to look into that. I get a little over 2,700 with that bullet out of my 35 Whelens. I could probably get another 100 fps out of them if I really pushed the envelope.

THis was pushing the envelope, but nothing others hadn't done. Recoil was fairly sharp. I think Bryce Towsley wrote a few articles on loading for it. I think he called it the 35 Sambar.

I considered it as well, but after shooting it as a 350 I figured 225's at 2700 would kill anything I'd use it for at any range I'd use it for and I really didn't see an upside to the added recoil. The rifle replaced a 350 Rigby that had more oomph, but also more weight.

We have a 'fire member, 358wsm who had Pac Nor put one together. He had a whole lot of fun working up loads for it. Pac Nor built, chambered and screwed in the barrel for him. It was a very accurate gun. I've seen that gun shoot, IMPRESSIVE! I suggest you send him a PM and ask about the particulars or ask him to post here about it. I know it'll sure kill moose.

Yep, It'll kill stuff.

With 65 grains of H 4895 it would clock 2930 fps with 225's.

With about 71-72 gr of RL 17 it would push 250's to the 2800 fps mark.

I believe it was the Aussie's that named it the "Sambar."

What freebore would you recommend for the 250's or larger. I don't have any bullets to mock up a round with....

I never understood why Winchester never went with it. They decided on the 32 WSM and it's deader than a hammer.

I bet a .338 WSM would've done better than the .325.

Well Sir,

I built mine in a rifle that had a 2.980" magazine. And how I set up the clambering was like this. I chose the 225gr NPT as my hopeful primary. Then I chambered so that I could kiss the lands just before I exceeded allowable magazine length. This allowed me to also load 250's up and out of the body of the case, at or above shoulder length, if you will.

Don't we all.

Winchester said something to the effect that it wouldn't compete with 338 Win Mag velocities. So what.? Who would have cared.? It would have been a bout the most perfect 338 out there, sans the 338-06 which is neigh unto impossible to find factory ammo for...if that matters.

Speaking of velocities. I never pushed my Whelen hard, 225's about 2630fps out of my 22" Ruger K1A, that was a full 300 fps behind my 358 WSM. Something to think about.

I've wanted to build one of these for years, I'd be willing to join you in building one. reamers should be available from manson, clymer, or ptg. let me know if you want to split the cost of one. I will probably use a schneider or kreiger barrel and a 700 action. what dies does everyone use? jim

I drew up a barrel contour that I liked, kinda heavy, 24" long and sent the drawings into Pac Nor and they did the entire build according to my specs, custom throating and all. Pretty easy.

I went with Redding dies. I no longer have the rifle, it was stolen. So if someone wants to do the build, I'd be willing to sell the dies to someone who needs them.

Edited to add:
I don't believe a long barrel is needed. As a matter of fact, I was going to have Pac Nor re-contour my barrel and chop 4" off it making it 20".
I'd say that 20" to 22" would perform just fine.

I'm definitely interested in the dies..... What are they? Full length or neck or bushing dies or ???

wouldn't it be better to use .325 brass instead of .300 brass?