Joe, I'm not sure about the OP's gun, but mine was simply an incredibly tight fit. If you have a large punch and a heavy, heavy hammer and hit it repeatedly while mounted in a good vice without it moving it can't be an adhesive holding it :-) Smith uses a large press to install the sights...and I'm sure the fixture the slide sits on offers perfect support so they can use a lot of pressure. The good thing is they never come loose. The bad thing is many are impossible/next to impossible to adjust or remove.
Actually, they do come loose, we had a couple almost lose the front sight in the first 100 rounds. They had to go back because they were so loose in the cut, the owner could not re-install them. I have also seen pics of the front sight installed backwards on the M&P web site.
This is one feature I wished they had copied from Glock as I have yet to lose a front sight on any of those with a little blue (not red) Loctite on the threads.
Pro/9L or fullsize/compact models came loose? The long slide guns have a reputation for being much tighter, for some reason, and lots of folks have had to cut theirs out. That could be because it's an entirely different front sight, in the same dovetail.
I'm thrilled they didn't copy Glock on the front sight!
I am also thrilled they didn't copy glock on this one. I replaced my front sight which was tight as hell and took some serious force to get off. I replaced it with a HI-VIZ FO front sight which was way oversized and even with some serious fitting still was a pain in the ass to get on. It makes it hard not to ding or damage a sight with a brass drift so some things are best fitted for a gunsmith. The hi-viz has such a little area to connect with to get on. I did find that freezing the slide and heating the sight up a little did help.