And to add to this, changing the part of your finger that is on the trigger to fire that gun to me means two things. 1- It's not the gun for you. 2- You are an experienced shooter that knows how to adjust for the gun.
Answer me this, would you carry a gun that you have to shoot with a different part of your trigger finger than any other gun you own? Remember the Shield is design for concealed carry.
Actually, yes... I'm at the point where I COULD pick up any of my Carry pistols and be comfortable in getting the right finger placement. But then, I don't 'rotate' my carry pistols for no reason (for the sake of rotating them?) and I if I did need to change my Primary Carry pistol, I WOULD Dry-Fire it a bit before going out the door.
My oldest carry pistol is a Gen2 G19 that I've carried since '89. Until I bought the Shield, my Pocket Carry EDC was a PF-9. I also have a G26, an XD-Service, XDM9c and the Shield. Each require just a little different technique, but I can take all of them to the range and from practice time, I can tell which it is as soon as it's in my hand and can shoot equally good placement and grouping. None have been modified from Factory Stock condition. I prefer to learn a pistol's platform, rather than modifying the platform to make it shoot like something else.
The PF-9 and the Shield did take the longest to master, as they are both Single-Stack Subcompacts (and the PF-9 being a 'True DAO'). With them, like so many other people, my initial groupings were Low-Left (or way Left). With the help of a spotter (Watching my hands and pistol, not the target), I was able to make adjustments and correct my shooter errors, which actually helped tighten groupings with my other pistols.
Many come to the forums saying they've been shooting all their life/career and never had problems like they're having with the Shield. Sorry... But Rarely can people transition from Double-Stack FS, Double-Stack Cs (or even 1911s), to Single-Stack Subs without going back to basics and start learning the platform from scratch.
BTW:... Where's the OP (Keith)?? Did he simply join the forum and start this thread simply to complain and not Follow Up??

I hope he wasn't just Trolling us.
