Since 1998 when I started lifting weights at the Battlement Mesa Rec Center, I've had numbers of people try to convince me that doing full reps on the bench press (touching the bar to your chest) is bad for your shoulders.
I believed the hype for a while. And, I'm embarrassed to say, that I've done a lot of half reps (maybe not half reps but stopped an inch above my chest).
I remember the day when I decided that I wasn't going to "painful shoulder" myth anymore and started touching the bar to my chest. I realized that what I thought was my bench press max, in reality, wasn't even close.
My goal from that point forward was to build my bench press max to a respectable number doing it the right way, touching my chest and locking my arms out at the top.
The goal of this post is to help anyone doing half reps realize a few things. 1) You're missing out on developing strength at the bottom of the lift, 2) You're missing out on more prominent hypertrophy (muscle growth) gains, 3) You won't hurt your shoulders if you're bench pressing with correct form.
If you're worried about injuring your shoulders by touching your chest lower the weight and fix your form. Try focusing on these three things: Raise your chest slightly as the bar comes down, squeeze your shoulder blades back, and keep your elbows at 75 degrees.
I'll just say it, half rep bench press reps are not okay. If you want to get the most out of your bench press, learn correct form and go all the way down. Don't make the "I don't want to hurt my shoulder" excuse. Don't make the "I don't have a spot" excuse. And definitely, don't throw any number out you've ever benched that you didn't touch your chest.
For a detailed explanation on bench press form read this article, "How to Bench Press with Proper Form: A Definitive Guide."