mizer67 Posted September 15, 2011 Share Posted September 15, 2011 I recently changed sights on my M&P 9mm, and now I can't get the rear sight to stay in place. Both my factory rear sight and the Warren I replaced it with will not stay put, and vibrate loose after a few magazines worth of ammo, even with red loctite on the set screw. Both rear sights (factory and Warren)are loose in the dovetail fitting, and can be moved/replaced by hand. I e-mailed Scott at Warren Tactical and he mentioned compressing the top of the dovetail into the rear sight by hammering it downward while the slide is held in a vice. Anyone have to try this to correct this issue? What can I use that won't mar the slide? Link to comment Share on other sites More sharing options...
whistlepig Posted September 15, 2011 Share Posted September 15, 2011 did u lose any of the tiny parts under the sight? also u can add material to the rear site with epoxy and or JB weld and then trim to fit. U want to start it with a very snug fit. I suggest trying to alter the sight rather than the slide. Link to comment Share on other sites More sharing options...
bhurte Posted September 15, 2011 Share Posted September 15, 2011 A couple questions come to mind to start with... • Did you have any trouble with loose factory sights before changing to the Warren Sights? • Did you Remove Material from the new Warren Sights to Install? There is a long-running history of extremely tight then too loose factory sights on M&Ps. I actually myself just sent back an M&P Pro 9mm where the front dovetail was cut slightly out of spec. My factory sight would work loose, and an aftermarket sight(Dawson) tapped in with little resistance. S&W replaced the slide and confirmed it was out of spec. Got it back in a little over a week. The second question around installation is because the tolerances in dovetails are very very small. It only takes a couple too many strokes with a file or sanding block and you've comprimised the fit. I actually had this happen to me with a "as-new" Warren sight i purchased off another forum. It showed up and would fall right out of the dovetail with no resistance as it was poorly fitted by the prior owner. Although, I wouldn't doubt Scott Warren – he does design and make the things after all...I would check these two scenarios first. Link to comment Share on other sites More sharing options...
GregJ Posted September 15, 2011 Share Posted September 15, 2011 (edited) I have no experience with the M&P, but I had a similar problem with my Kimber when I replaced the rear target sight. I put Gun-Tite (specific product for guns) under the sight and on the set screw, it's supposed to fill in a few thousands of space. It worked for me, might work for you. EDIT: Here is Loctite 620 from Dawson's website. It's the same stuff in his videos on replacing front sights. Edited September 15, 2011 by GregJ Link to comment Share on other sites More sharing options...
Fried Chicken Blowout Posted September 15, 2011 Share Posted September 15, 2011 I've had the same issue with two M&P pistols. They were fine with the factory sight in them, but the Ameriglo that I used to replace it were loose and only the set screw was holding it in place. I use blue loctite to "bed" them in place. just cover the dovetail area with the loctite and slide in the sight. Fill the screw hole with loctite and tighten it down. Never had a problem after that. Once it's dry it's rock steady. I got blue loctite down the firing pin block hole once and had to remove the rear sight to clean it out. The sight slide out with the tool and was a press fit going back in. The loctite stayed hock hard and filled the gap like it should. Link to comment Share on other sites More sharing options...
whistlepig Posted September 15, 2011 Share Posted September 15, 2011 Ok.............. "Fried chicken blowout" is in the running for the name of the day Link to comment Share on other sites More sharing options...
Fried Chicken Blowout Posted September 15, 2011 Share Posted September 15, 2011 (edited) Totally fresh... Totally original... Totally fried! Try my new line of Fried Chicken! Just kidding... I got the name one night becuase on the way to a 12-Hour night shift I picked up an over sized box of KFC and ate the whole box. Then spent the next 12 hours blowing it out my ass... Edited September 15, 2011 by Fried Chicken Blowout Link to comment Share on other sites More sharing options...
98006 Posted September 15, 2011 Share Posted September 15, 2011 the newer models the rear sight are loose in the dovetail. its is held by the set screw. did you take any material off the slide dovetail? if you did not, I would clean the set screw hole with a good degreaser and then apply BLUE loctite making sure that it gets into the hole. you may need to use a pin or such to pop the air bubble that sometimes keeps the loctite from flowing into the hole. Then tighten the set screw and let dry. I've never had to use gap filling loctite on a site that has a set screw. Link to comment Share on other sites More sharing options...
mizer67 Posted September 16, 2011 Author Share Posted September 16, 2011 A couple questions come to mind to start with... • Did you have any trouble with loose factory sights before changing to the Warren Sights? • Did you Remove Material from the new Warren Sights to Install? There is a long-running history of extremely tight then too loose factory sights on M&Ps. I actually myself just sent back an M&P Pro 9mm where the front dovetail was cut slightly out of spec. My factory sight would work loose, and an aftermarket sight(Dawson) tapped in with little resistance. S&W replaced the slide and confirmed it was out of spec. Got it back in a little over a week. The second question around installation is because the tolerances in dovetails are very very small. It only takes a couple too many strokes with a file or sanding block and you've comprimised the fit. I actually had this happen to me with a "as-new" Warren sight i purchased off another forum. It showed up and would fall right out of the dovetail with no resistance as it was poorly fitted by the prior owner. Although, I wouldn't doubt Scott Warren – he does design and make the things after all...I would check these two scenarios first. Didn't have trouble with the factory rears until I removed them to install the Warrens. However, they also push out without any resistance and were just held in by the set screw. I didn't remove any material from the Warrens for install, they just slid in like the factory rear and are only held in place by the set screw as well. I have 2 other M&Ps and they dovetails are tight enough. Link to comment Share on other sites More sharing options...
bhurte Posted September 16, 2011 Share Posted September 16, 2011 I would give S&W a call and describe your situation. They will send you a shipping tag and get your gun taken care of rather quickly. Should you modify your slide, you may lose this luxury later. Link to comment Share on other sites More sharing options...
JeremyM Posted September 16, 2011 Share Posted September 16, 2011 my warren rear sight was loose when I installed it. A little jb weld on the bottom of the sight pushed the sight up enough to keep it tight. About 10k rounds and still in the same place when I installed it Link to comment Share on other sites More sharing options...
jer Posted September 21, 2011 Share Posted September 21, 2011 i had the front sights come loose on 3 of my m&p pro 9mm . jerry Link to comment Share on other sites More sharing options...
fiddler Posted September 30, 2011 Share Posted September 30, 2011 Sights are unecessary. Use the Force, Luke. At the very first local USPSA match I ever went to I struggled with a plate rack. I think I needed two reloads to clear it. The next shooter smoked the whole stage and mowed down the plates in less time than it takes to tell about it. After he was done he asked us to help him find his front sight, it had fallen off as he drew his pistol. For us mortals though, a little loc-tite works wonders. Link to comment Share on other sites More sharing options...
DamonHP Posted October 27, 2011 Share Posted October 27, 2011 My front sight on my PRO 9 would drift to the left after 100 rounds or so. It was frustrating. I put a ton of red loctite on it and it stopped moving. I presume the front slot is out of spec by .0005 and leaves just enough room for the recoil to walk it left. I have not sent it back to S&W, but they would undoubtedly exchange it. Link to comment Share on other sites More sharing options...
eric4069 Posted October 27, 2011 Share Posted October 27, 2011 On my MP pro the factory rear sight was initially quite tight. However after I moved in in and out a few times to work on the striker block and striker assembly it loosened up and can now be moved by hand. I feel it was my manipulating it that made it looser. I may have to try some of the ideas above. Eric Link to comment Share on other sites More sharing options...
Blazetech Posted February 21, 2019 Share Posted February 21, 2019 Hey guys thanks for putting this out there. My 9mm has the same issue with the front sight walking to the left after a couple times at the range. Link to comment Share on other sites More sharing options...
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