I made a thread a few months ago about my night sight debacle.  In a nutshell, I took my M&P 45 to a local gunshop to have night sights installed.  The shop ened up breaking the original sight when removing it.  Then they broke the new front sight trying to install it.  They eventually replaced the sight they broke and successfully installed it on my M&P.  Anyway, I was at the range today and after fifty rounds the rear sight starts flopping around and almost completely fall off the gun.

My question is, shouldn't the sight fit on snugly, where you have to tap it into place with a mallet?   Even if the allen screw(?) came loose, I don't think the sight should almost fall off the pistol.

Should I bring it back to them or just sight it in and locktite it?

I stopped trusting them half way through your first post on the subject.  Are they the only, or 'best' smiths in the area?  





 

The correct fix for a sight that is loose in it's dovetail:
Take a very sharp prick punch or very small chisel (I use an automatic center punch-doesnt jar the sight too badly) and put half a dozen punch pricks on the bottom of the sight, You dont have to blast the punch with a 2 pound, just raise some dimples on the bottom flat. Some guys like to punch the slide, I prefer to punch the sight-cheaper if you  pull an "Oops" but there are some slides you can leave skid marks on from the dimples. On those particular pistols dimple the slide but only where the sight sits. Also with your sight being night sights you dont want to damage the Tritium vials.
Install as usual and snug the set screw-sight the pistol in and when you are SURE the sight is where it needs to be place 1 drop of red LocTite in the screw hole-give it a second to "creep" under the sight and snug the screw down tight. Let it sit for at least 12 to 24 hours before you shoot it again.

Kinda new to the area, so I just took it to a gunshop that I've made a few firearms purchases from.  They seemed like they ran a tight ship, so I took it to them.  Never again

the tip


Thanks for the tip!

But, now that I'm thinking about it, when the shop ordered me a new sight, it came with both front and rear sights. I believe the shop gave me the box with the second rear sight.  I'm gonna try and dig it up and see how it fits.  

I'm also going to try the prick trick on the loose sight and see how that goes.