[pug]

Spook you are talking about a whole lot more case capacity than I am. The guy at the shop shoots TCU and the cases are a little long for what I had in mind. I was looking more at a 30 degree shoulder and case capacity just shy of 25 grains. In order for the cartridge to run fairly smooth at full auto rates the cartridges must stack correctly in the magazine and that is why I think I would go with a shorter case. As far as velocity I am not going to guess although the computer that doesn't always know what it is talking about says over 2200 fps for a safe load out of a 16" barrel. It also says pressures can go up to a max of 70,000 psi so I don't think there is a problem of not enough pressure. I got the cartridges made up and most of the specs filled out but I may still lengthen the neck.

You know I looked at over 75 different 308 cartridges and still didn't see the 30 TCU which I knew about. I was also surprised to see the 30-223 had less case capacity than the 300/221.

Not sure this was the right place to post this subject so forgive me if I made a booboo.