6.5 WSM Neck Tension

[parshal]

First, I'm reloading 6.5 WSM with Norma brass. Neck wall thickness is around .017". A loaded round is .298". For reference, when using a Redding 6.5-270 non-bushing die the necks are sized to .291".

I've been using a .293 bushing in a bushing die but, for the life of me, can't remember how I came to that number. Maybe my necks have gotten thicker after running the brass twice (I load hot) but that's a lot of growth. I see .291 mentioned quite a bit for the SAUM (I've not measure my 6.5 GAP 4S neck thickness yet).

For now, I've got a .296 bushing in the die which should be about right for a loaded round being .298 but that just seems quite large to me. I guess I could trim the necks back but my reamer's neck diameter is .300 so any less would be excessive on my brass.

Just seeing what comments I might get here.

Thanks!

 

[eklarsen]

I think you have exactly right... a .296 bushing, .298 loaded round in a .300 chamber. that is about as good as it gets.

 

[parshal]

What amazes me is that a non-bushing die sizes to .291". What brass did they base that size on? I guess if I were using the expander ball it would be good but work the brass pretty hard.

 

[Mikecr]

.296 is right, and include expansion after downsizing.
A 6.5-270 die isn't a 6.5WSM die, 270 brass is not WSM brass, so I don't know why you thought that would work..

 

[parshal]

Sorry, my bad, it's a 6.5-300 WSM die.

REDDING DELUXE DIE SET, 6.5/300 WSM | Brownells

 

[Mikecr]

Apparently Redding doesn't learn about cartridges on their own.. I'd get my money back on the die set, with reporting of the obvious issue, and maybe they'll learn with that.

 

[parshal]

Luckily I've got a couple bushing dies I can use!

 

[orch]

I can't remember for sure what they were turning the 6.5 4s necks to for the "necked" chambers but I think they were taking them down to 0.0145" to 0.015"...

0.264" + 2x0.0145" = 0.293" hence the 0.291" bushing to give 0.002" tension in the 6.5 4s neck turn version...

As far as the redding 6.5x300wsm non-bushing die being 0.291", redding has no idea what everyone's brass thickness is going to measure so they hedge on the small size and if the neck is sized excessively small the expander ball will bring it back up to proper size... it just works the brass a lot, that's why I have started switching to mostly bushing dies for must of my caliber since...

Orch

 

[parshal]

I've got an AMP annealer and the Norma brass they tested to determine the setting was .0155" so I'm guessing I just got a thick neck batch of Norma brass.

 

[dok7mm]

parshal, I shoot several 6.5s, but not familiar with the Norma 6.5-wsm brass. Are you necking down to .264 from a parent 300 wsm case?