Loose front sight screw on my new Mark IV Hunter

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Mick5150

Bearcat
Joined
Feb 3, 2017
Messages
7
Hi gang,

I purchased the new Mark IV Hunter about a month ago and I'm having problems keeping the front sight screw secure. The front sight starts to becomes loose after shooting about 6 or 7 mags. The front sight will literally turn sideways and fall off if I don't tighten it. I carry a small screwdriver to the range to fix it, but it becomes even worse once the barrel warmed up....... it's loose after each mag! I tried Blue Lock Tight, but it does the same thing. Is this a common problem? Any ideas? The front screw seems very short, and does not go into the barrel very much. Any help would be appreciated.

Thanks,
Mick

P.S. I'm also having issue finding the right ammo that will not jam in the gun, but that's another story. I will post another topic about that.
 
Joined
Dec 17, 2015
Messages
2,159
Location
Reading, Pa
Welcome to the forum. Clean the screw, clean the threads in the barrel, let dry. Apply blue Loctite to the screw and assemble, let dry. That should work, Loctite won't work in the presence of dirt and oil. As far as the ammo goes, clean and lube the gun if you haven't already and any high velocity round nose ammo should work fine.
 

Qman2

Bearcat
Joined
Jan 18, 2017
Messages
4
If you don't know about Loctite and choose that route, you must specifically use the 'blue' Loctite like Blackhawk mentions. Some Loctite options lock the screw so tight it requires a torch to heat it up for removal and you don't want that if you decide you want to remove the screw later.
 

SGW Gunsmith

Blackhawk
Joined
May 15, 2010
Messages
966
Location
Northwestern Wisconsin
Mick5150 said:
Hi gang,

I purchased the new Mark IV Hunter about a month ago and I'm having problems keeping the front sight screw secure. The front sight starts to becomes loose after shooting about 6 or 7 mags. The front sight will literally turn sideways and fall off if I don't tighten it. I carry a small screwdriver to the range to fix it, but it becomes even worse once the barrel warmed up....... it's loose after each mag! I tried Blue Lock Tight, but it does the same thing. Is this a common problem? Any ideas? The front screw seems very short, and does not go into the barrel very much. Any help would be appreciated.

Thanks,
Mick

P.S. I'm also having issue finding the right ammo that will not jam in the gun, but that's another story. I will post another topic about that.

Some of it has to do with the "slotted" screw in that front sight. The cleaning of the threads is indeed imperative to allow the thread-locker to do its job. I now replace those front sight screws with a much better screw that will take some torque.

 

Mobuck

Hawkeye
Joined
Dec 25, 2007
Messages
7,797
Location
missouri
If blue locktite doesn't hold, get some bearing and stud retainer(similar to locktite but nearly permanent) and try that. As mentioned, you must remove all traces of oil from both external and internal threads.
 

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