So I had a chance to handle a S&W shield in .40 and a Springfield XD-S .45acp this weekend and both are pretty much equal in size, weight and feel. The only exception is an extra round in the shield. I was crunching some numbers, out of a 3" barrel a standard 180 grain .40 round is coming out at the same speed as a 185 grain +P .45 round. http://www.ballisticsbytheinch.com/40sw.html http://www.ballisticsbytheinch.com/45auto.html I know you can go heavier with a .45 round, and a .45 makes a slightly bigger hole, but is a 45 really that much better coming out 3" barrel then a .40 to warrant a loss of one round. http://www.smith-wesson.com/webapp/...80153_757781_757781_ProductDisplayErrorView_Y http://xdspistol.com/ Wanna kill these ads? We can help!