RE: .270WSM vs Antelope/Mule Deer
My primary hunting rifle is a .270 Ackley Improved, which is about identical to the .270 WSM. I not only use it with great confidence on antelope and mule deer, but is it also my "go to" elk rifle. You may have somehow gotten a bad bullet in that experience you describe. Most of the time, the WW silvertip/Nosler Ballsitic Tip bullets make a very large wound channel.
Most 130 gr. bullets in this caliber are ideal for deer hunting. The Sierra Pro Hunter, Hornady Interlock, and Nosler Ballistic Tip are all good. The bonded bullets - like the Nosler Accubond, Hornady Interbond, Speer Trophy Bonded Bear Claw, and Swift Scirocco - will allow you to take deer and even bigger game without running into penetration issues. And most 150 grain bullets are going to give performance very similar tocomparable 180 grain bullets in the 30/06 caliber. The Sierra 150 SPBT and Hornady 150 Interlock can handle game as large as elk and even moose. Nosler Partitions and Barnes X bullets will shoot clear through elk on a broadside ribshot and can break bothshoulders of a large animal withoutcoming apart.
The .270 WSM, IMO, is destined to become oneof the all time bestnorth american big roundsever chambered. Give it a chance . . . . .