necking down cases-need advice

[Bobthenailer]

I am working on a winter project and this will be my first attempt at necking down to a diffrent caliber. What I have is a parent case,6.5x55 swede) and I want to neck down to 6MM before I fireform to 6mmx55 ARCH Improved. Can I just use a redding neck bushing die with .257 and then .243 bushings to reduce the neck. And yes I will use imperial sizing wax.

Thanks for any info you can offer.

 

[trappst]

Yes, you can do it that way. However, you'll probably have better results by doing the neck down in smaller steps. By using slightly smaller steps, you'll reduce run out and end up with more concentric necks. Also be aware that the size of bushing may not be what the neck ends up at.

There was another post here at one time that explained it better, but I'll give it a try. Basically, as the neck enters the bushing it tends to follow the chamfer on the bushing instead of the inside diameter.....kind of a funnel effect. This is normally only the case when using a large step and it's not a big deal but it's something to watch as you may end up missing your target neck size.

To give you an idea, I use four steps to neck down 6BR to 20BR. First is the 20BR seater with no guts, then a 22BR body die, then a .235" bushing and then a .232" bushing with carbide expander. This keeps the run-out to a minimum.

Edit: Just read your post again - .257 and .243 bushings will be too small. Ya gots to remember the neck thickness! Also, your necks will get thicker and longer as you neck down so be prepared to trim and possibly neck turn,depending on your chamber).