Welcome to the forum. I don't have a Shield, but have put a few rounds thru one a friend has, also a 40. I thought it handled better than a Glock 27. My friend has not complained about any problems with the gun. If you get one, remember to clean and lube it before hitting the range and break it in with FMJ first. I haven't reloaded firbyears and am not really a 40 fan, but there is plenty of good data. Get you a reloading manual with data for the 40.I. one thing with all M&Ps, the trigger is gritty out of the box. Cleaning, good lube, and dry fire will all help smooth it out, but the grit is usually gone after the first 200 rounds.