THe .270 A/M is based off the 7mm or 300 RUM case. Either are simply neck sized and fireformed and are ready to load up to top end. Both of the weights are awesome from this round with the 169.5's running up to 3450 or the 195's running up to 3200 it makes for a very sweet top end preformer.
Some choose the corn meal route to fireform, I am a clutze when it comes to that so I just stuck to using normally loaded rounds. I had a supply of some old Nosler 150gr Solid Bases on hand and tried them over 98grs of 872. It gives me a mild load running just over 3450 fps and generally groups like this at 500yds,
The only drawback with this round, if you could call it that, is the lack of bullet weights available in this caliber other than the Wildcats. Going with a 7mm or 300 RUM, you get a wider asortment of weights readily available, but with either the 169.5 or the 195 Wildcat in the .270 A.M. you are hard pressed to want for more.
For more info on some of the A.M.'s you might look under the following link, Allen Mag Shooters Group