Necking brass up or down

[Jcalder]

Going thru my brass I realized I have a lot of 308 brass but few 243. I have roughly 225 Winchester pieces. I have around 50 hornady pieces. If I wanted to neck some down to 243 what would be the proper technique. I'm sure I need a die in between. I'm also positive I need to anneal somewhere in the process. All this is new to me but with winter coming I've got time to tinker. And that's basically what I'm looking to do.

 

[walker]

simply run the 308 brass through a full lenth 243 die and you have it no in between needed, may need to trim.

 

[Plateau Hunter]

It would be best to anneal and you can do that by rotating the neck over the tip of a candle flame while holding the case head in your fingers until the head gets too hot to hold. It probably can be resized down in one step but you could buy a 7/08 sizing die to get it half way there first.

 

[Jcalder]

I guess I got anxious. I annealed per the instructions above. Heavily lubed and ran a few thru



Do I need to anneal again or am I good to go. Also noticed where the shoulder and neck meet is not exactly formed. After firing will this correct itself

 

[mr.big]

the case will blow out to fit the chamber perfectly on the first firing,,since you annealed first I would load and shoot then anneal ever 3 cycle and it will last a long time,,

going that far I would use a 7-08 or 260 first then go to 243,,make sure to measure case length and trim as needed as the cases may lengthen a little sizing down that far,,

I have 100 pieces of Lapua brand 338 LM brass that have been loaded 8-10 times annealing ever 3rd loading,,but I am running about 4 grs below max

 

[Jcalder]

I went from 308 straight to 243. Took a little pressure and I thought I might get a stuck case but it all turned out. I measured and they are .015 short of the trim length. After firing them once I may trim just to square the neck in case I have more runout on one side. I do agree a die in between would be ideal as it wouldn't work it all at once.

 

[vonb]

Watch your neck thickness and make sure that it isn't too thick. If it is, you may have to turn your necks. I agree with having a mid-step in necking down to 7-08 or 260 first.

 

[Jcalder]

Watch your neck thickness and make sure that it isn't too thick. If it is, you may have to turn your necks. I agree with having a mid-step in necking down to 7-08 or 260 first.

I've thought of that with the neck thickness. I hope to get one in the next few months. I know it would help me out.