Neck Up or Neck Down

[AitchAr]

I'm planning my next build and I'm 90% sure it will be a 6mm Rem AI (also considering the 6mm Super LR). I know Rem and Win make 6mm brass and besides normal brass prep, all I'd have to do is fire form.

However, I've found some 5.6x57 RWS and 7x57 Norma brass. Since I've never necked up or down brass (or possible neck turning or inside neck reaming that might be required), I thought this would be a great time to learn.

So, of those two choices which would you do and why?

Thanks.

 

[Varmint Hunter]

I'm planning my next build and I'm 90% sure it will be a 6mm Rem AI (also considering the 6mm Super LR). I know Rem and Win make 6mm brass and besides normal brass prep, all I'd have to do is fire form.

However, I've found some 5.6x57 RWS and 7x57 Norma brass. Since I've never necked up or down brass (or possible neck turning or inside neck reaming that might be required), I thought this would be a great time to learn.

So, of those two choices which would you do and why?

Thanks.

I shot the 6mm AI for many years. The best option for quality brass and consistent loads was to neck down Norma 7x57 brass. Slight neck thickening is normal and you may (or may not) need to neck turn, depending on chamber dimensions. I always neck turned to maximize uniformity. If you use a tight neck chamber you will need to neck size anyway.

Using Rem brass resulted in measurably larger groups. It all depends on what level of accuracy you are looking for. You may find the Rem brass acceptable after careful prepping.

You can find quite a bit of helpful information at this site:
Mike J's 6mm Ackley Improved Reloading Page

 

[AitchAr]

I shot the 6mm AI for many years. The best option for quality brass and consistent loads was to neck down Norma 7x57 brass. Slight neck thickening is normal and you may (or may not) need to neck turn, depending on chamber dimensions. I always neck turned to maximize uniformity. If you use a tight neck chamber you will need to neck size anyway.

Using Rem brass resulted in measurably larger groups. It all depends on what level of accuracy you are looking for. You may find the Rem brass acceptable after careful prepping.

You can find quite a bit of helpful information at this site:
Mike J's 6mm Ackley Improved Reloading Page

Thanks for the reply. The site you linked is one of many that I've booked marked for this build

After more research, it does seem that necking down Norma brass will work better than necking up the 5.6 RWS brass. And like you, I'm not a big fan of Rem brass. I typically use Norma whenever I can and Hornady as a second choice.

As for accuracy that is acceptable for me; I plan on squeezing every last 0.1" out of it out on paper, steel, and game. I plan on testing out the Berger 105 hybrid, 115 vld, and 117 Matrix. I'll also develop a load for the 100 gr CE in case I make my way the range of the California Condor or when the brain trust that is running California decides to outlaw all lead bullets for hunting.

Thanks again for your reply.