I'm going to build a 358 Norma. The plan is to rebarrel a rem 700 BDL in 308 Norma. I have 2 308 Norma and figure about as easy as it gets to 358 going with another Hart barrel

My question is best barrel length? Twist I figured 1-12 with the 250gr oryx bullet

That's pretty cool. I have been plotting my next 35 magnum. I have two barrels, ones a Krieger 1-10 and the other is a Benchmark 1-9.5. 1-12 will work fine but I am holding onto enough old Bitterroots that I was advised it's worth building a rifle around!

Good luck with the build, looking forward to seeing how you make out with it.

the 1-12 will work, but so will a 1-10.
I've had em in 22, 2 and 24" lengths and didn't really see much of any velocity difference so I'd build more for balance and handling than anything.

My .358 Norma mag barrel is 26" long.

Mine is 22" and balances nicely. I would not hesitate to go shorter if building again. I actually wanted shorter but was repurposing a used barrel and the flutes wouldn't allow any shorter.

Ok, if I were you, I would send it to J E S in Oregon, have it cut to 22" +/- and have a Ballard-Rifling Cut-into that Existing Bbl, and for $3-400.00 your Good to Go, and then some.....
Lj in Alaska.....

Nice to see people making rifles instead of trying to use the lightest little rifle they can. A world of pussies.

My 16 twist 22" barrel works well for my uses with bullets as long as 1 1/4" (Speer 250 Spitzer). Maybe if copper solids are in your future a 12 or 14 twist would make more sense?

https://bergerbullets.com/twist-rate-calculator/

My rifle balances, points, & handles well. Hell, it's just a rechambered 700 Classic.

Also see here...

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/17164210/1

That rifle would be in the box and shipped to JES, in the effective range of the 358 Norma their rebore is just as good as anything you can by off the shelf or purpose made, I have rebored several, last one was a short chambered 308 norma, became a killing machine, I have a 22", 24" and 26" in the 358 norma, nothing on the recieving end has ever noticed a difference. One rifle, the 22' barrel is dialed in with the 250 grain factory Norma ammo, other two are shooting 185 grain Barnes TSX, all shoot as good as I can hold it.

Mine is a 1:12…shoots the 250 partition and the 225 TSX very well. Doesn’t care for the 250 Speer (2” or so with H4350)

Ty for the help I decided to stick with hart a 24 inch 1-12 twist

I made mine 23".

Tony

The only .358 Norma Mag that I have ever seen was built on a 1917 Enfield action with a 24” barrel. Very cool gun, wish I could’ve fired it.

It belongs to a local guy, he has been filling his elk tag with it for years!