ruger mark iv hunter front sight loose

[JQIAN]

My ruger mark iv hunter front sight kept loosening up, the screw holding the plate just doesn't hold.
the funny thing is that I cannot find any of my screwdrivers to fit this screw.
Can anyone please point me to the size of this screw and/or show me where to find a screwdriver to tighten it up?
thanks

 

[nitroxace]

My ruger mark iv hunter front sight kept loosening up, the screw holding the plate just doesn't hold.
the funny thing is that I cannot find any of my screwdrivers to fit this screw.
Can anyone please point me to the size of this screw and/or show me where to find a screwdriver to tighten it up?
thanks

I had the same issue with my MKiV Competition. I actually replaced the front sight with a fibre optic and used Loctite. But to answer your question I used a 5/64 to remove it. You could probably get a 2mm to work as well,

 

[JQIAN]

I had the same issue with my MKiV Competition. I actually replaced the front sight with a fibre optic and used Loctite. But to answer your question I used a 5/64 to remove it. You could probably get a 2mm to work as well,

I think the only difference between between the competition and hunter are the front sight plate. The hunter itself has the steel plate front sight with fiber optic.
Loctite is a good idea. I will get 5/64 hex screwdriver to see if it fits/works.

 

[4n2t0]

Yup, blue loctite.

 

[JQIAN]

Yup, blue loctite.

well, I applied blue loctite and waited for more than 24 hours before heading to the range.
Guess what, it's still loose after I shot about 100 rounds.
I feel the screw itself might be defective though. Maybe it's too small or too short?

 

[4n2t0]

Blue loctite's semi-permanent and shouldn't allow for that kind of movement. I would tell you to use red loctite but that means 1) You would need heat if ever to remove and 2) I'm pretty sure somethings wrong with your threads, check for proper engagement.

 

[CzyHorse]

Yup, blue loctite.

well, I applied blue loctite and waited for more than 24 hours before heading to the range.
Guess what, it's still loose after I shot about 100 rounds.
I feel the screw itself might be defective though. Maybe it's too small or too short?

Did you clean the threads?
I used a de-greaser (acetone) on the threads. De-grease the screw threads & internal threads in the barrel, let that dry, then used blue loctite. Sight on my Hunter has not moved since.

 

[nitroxace]

Did you clean the threads?
I used a de-greaser (acetone) on the threads. De-grease the screw threads & internal threads in the barrel, let that dry, then used blue loctite. Sight on my Hunter has not moved since.

100 percent you need to clean and de-grease the threads prior to applying the Loctite, I forgot to mention this in my initial post.

 

[JQIAN]

100 percent you need to clean and de-grease the threads prior to applying the Loctite, I forgot to mention this in my initial post.

ok, degreese then, I will do it tonight.
I will borrow my wife's nail polish acetone. Is that the same thing?

 

[4n2t0]

ok, degreese then, I will do it tonight.
I will borrow my wife's nail polish acetone. Is that the same thing?

It might be as long as it truly contains acetone, rubbing alcohol should also be sufficient. Just make sure to allow whatever solvent you use to completely evaporate before assembly. Also, as before always allow loctite to cure for 24hr.

P.S. Most people apply too much loctite, a single light strip across the threads is all it takes.