Case runout.

[350 Mag]

I have 4 bags of R&P Brass in 7mm Saum.

It's hard to find (especially in Canada)

Trouble is the necks have .0035-.004 runout.

Accuracy of rifle shooting finished ammo is acceptable but is there a way to correct this runout?

I have a Lee Collett die coming will this help or it won't exert enough force to straighten.

Or

Redding Bushing die.?

I am also getting some ADG brass but would like to get a few firings out of the Rem. brass.

 

[spife7980]

Are you sure it’s runout and not differences in neck thickness?

Also, firing them in your chamber will leave them runout free (provided your chamber is)

 

[Ryridesmotox]

I have been using a lee collet on my 308 brass. It leaves stuff really straight. You may want to try the smaller mandrel for some more neck tension as well. I have an undersized mandrel for my 308. I added mine to an amazon order and it was like 5 bux I think. I still have to test it to see if it makes a difference. I get better accuracy out of my gun with my collet than my full length sizing dies. I just wish I could bump the case shoulders a bit more with the collet die. Still working with them though to figure shit out.

 

[350 Mag]

Lee is making the Collet Die with sample brass and bullet.

Thanks for tip about checking fired cases.....checked and they are .001-.0015 runout now.

Will check case necks but all I have is RCBS runout gauge so not the best tool to check neck thickness.

 

[Steel head]

Between the collet die and fire forming they’ll probably get ironed out pretty damn straight.

you’ll maybe have to cull a few out of your super anal.

I use Winchester brass for my 260 it it’s plenty wonky out of the bag but after the second loading it’s GTG.

Remington SAUM brass is rarer than an honest politician.