Looking for advice on necking down brass for wildcat

[CaptainChilders]

I have 150 new brass for a 7 Mega by Sherman Wildcats which for those unfamiliar is basically a 7wsm with an improved shoulder. The brass new comes in 30 cal and needs to be necked down. I’ve done quite a bit of reloading just for some reason have never necked brass down. I’m sure theirs several ways to do it but I was hoping to get some insight from someone with some experience in the matter. I have a Hornady full length size bushing die and 100 brass that were already necked by someone else but their primer pockets are giving up. I do not have a neck turner and also looking to see if I need one. What’s your method?

 

[Jonas]

Anneal first if you can, use good case lube, and neck them down gradually with progressively smaller bushings instead of doing it all at once. After sizing, trim and chamfer the cases and check neck thickness/runout. Most guys don’t need a neck turner unless the necks thicken up enough to cause tight chambering or inconsistent tension. Since you already have formed brass, measure loaded neck diameter on those and compare it to the new stuff that’ll tell you pretty quickly if turning is necessary. Also watch for donuts forming near the shoulder after a few firings.

 

[turbobrick]

That isn't too much of a neck, so it should go pretty smooth, I'd just go straight to FL sizing with your 7M die, shouldn't need annealing with new brass. One thing with necking down, it pays to use minimal to no lube right on the shoulder itself. Really any lube in that area can cause dents in the shoulder from hydraulic forces.

 

[Redmt]

I've resized .223 to .300 BO. 6.5 Creedmoor to 22-250 and .270 to 25-06. As was already said, anneal if necessary. Don't try to do a quick resize in one stroke. DON'T LUBE the shoulders. I've used Imperial dry graphite on the necks.

 

[44hunter45]

Since you have a bushing die I would run it in steps. Ditto on not lubing the shoulders, although the dimples will blow out when you fire form.

The donut on the inside base of the neck can drive up pressure quickly and make seating hard. If you are not pushing the shoulder back it is not as big a risk. Since this is an improved shoulder angle I would expect less brass flow into that area. Still something to watch for.