Cooper owners: what's the M56/M52 Delta?

[FLChinook]

If you go to the Cooper web site and Build Your Rifle, you find the M56 is missing. I called Cooper and they say the M56 is discontinued, although it's available as a special order. They say the machining costs for the M56 are $600 more than the process they use for the M52 which, they say, is a little shorter and lighter but equally strong. The Cooper rep said there was absolutely no reason to spend the extra $600 +\- to have the M56.

I'm having a hard time grasping this. Surely something else is different. Has anyone used both actions and can say something about these two actions? I will probably only buy one Cooper and want it to be right.

I'm looking at a 7mm Rem Mag.

Thanks

 

[FLChinook]

I called Cooper again. The difference was described as programming for the machining process. The M52 is newer and the programming allows for more efficient machining, i.e., about an hour less machining time. The M52 is an ounce lighter but that might be in shortening it.

Perhaps you could use longer bullets in the M56 but $600 is a lot to pay for that option...