What do you use to lock screws in place?

The screws in my weaver base come loose on me.They only seem to come loose in the middle of important matches but it sorta, kinda really messes with the score. I use the red locktite and it works 90% of the time. Is there something better I should be using? I don't need to take this base off again, ever. If it stays in place.

Thanks for response, Len

Red loc-tite is not recommended;  it has to typically be heated to remove the screw. Blue loc-tite is recommended. I can't remember the # off the top of my head. You should remove your base screws and ensure that the threads are not excessively worn and you are getting at least 4 revolutions/threads of engagement.  Clean out slide holes and srew threads before loc-titing back together. Wait 24 hours before shooting pistol. 
Jon

I've never needed anything other than Blue Loctite. I always make sure that the screws and holes are completely clean and degreased. Rubbing alcohol works.

Purple loctite, lowest grip of the loctite products - a little difficult to find in hardware and auto parts stores. Found my through AMAZON. Sufficient hold strength for gun parts and easily releases with heat from a soldering iron.

Update: Switched to blue locktite. Cleaned threads with alcohol. Inspected screws for wear. Replaced with new ones on general principle. Tested to see if I had four full turns. I was only able to get at a max 2 1/2 turns on any screw old or new. I had a lot of aluminum left in the base so I went to my shop and sharpened the right size drill bit at the same angle as the taper on the base screws. I removed less than a 1/16th of an inch and tested. I now have just over 4 full turns on every screw. Thanks for the advice.

Len

The 4 turns is an approximation for the screw to obtain full shear strength. You also get some from friction of the base being screwed to the slide. 
Jon

I'm making some assumptions here, such as assuming this is a single rail mounted on a 1911 slide with a standard scope on top, but let me know if/where I may be wrong.

There are a few things to check first:

1.  Make sure the concave radius of the mount is smaller than the convex radius of the slide.  The edges of the mount should be able to contact the slide prior to the center, so that tightening the screws causes a tight connection of the outer edges.
2.  Make sure the holes in the slide aren't oval shaped from the prior times it loosened.  If they have elongated, they will allow further shifting.
3.  Make sure the screws haven't deformed.  If the screws have deformed, they are likely stretched and prone to failure.

If the above conditions are met, make sure the slide top and base bottom are very clean, as well.  (Especially since you mention not ever needing to remove the base), I recommend some form of adhesive between the two, although there are many successful mountings in use with none added.  I always use a thin line of red Loctite between the outer edges contact line on my 1911s and clean off the excess as soon as I mount the base.  Epoxy can also be used.  The adhesive will help keep the mount from shifting fore and aft during recoil.

Ed

    The mount I am having troubles with is on a 952. The top of the pistol is perfectly flat. I did put a dab of the red locktite between mount and rail this time. I almost put JB Weld. This pistol has given me problems since I decided to put a scope on it. The only commercial available mount cost about 100.00 and only has one screw that is supposed to hold it in place. That doesn't work at all. I made my own mount out of a weaver mount that fits a octagon barrel marlin. I think I just wasn't getting enough screw into the threads now. By drilling the base another .050 deeper I get 2 more revs and it cleaned up any oblong problems at the same time. I think I have it now. I am sure I wll find out in Regionals next month if that is true. Thanks again everyone for the input.

Len

blue Loctite if you ever want to remove them, red if its a permanent install or green if you want to lock in screws already in place

I cannot even estimate the number of slide mounts that have passed thru this shop.. Many were loose or had broken free of the slide. No.# 6 allen heads are greatly lacking, for this application, which can only be described as severe use, in my opinion.  Many years ago, I switched to  8X40 Torx head screws.. I drill and tap completely thru the slide for all holes ahead of the slide locking  lugs.. The screw length is then adjusted on a surface grinder to approx. .015 short or protrusion..  Two screws to the rear of the ejection port, I drill and tap to within .020/.025 of the firing pin bore, and the screw length is again adjusted to maximum depth. I use three screws in the front, and two in the rear..= 5 total as minimum..Most of the Micro mounts I install have at least two No.# 10 countersunks.. All holes are tapped between centers, producing a high quality pitch.. Normally, I do not use loc tite with this set up, as the thread bearing surface provides a secure torque..
Over Kill...??? One BE smith once told me I was nuts.. OK I have never had a return repair..the casual observer will not even notice the #8 screw unless it is disassembled. Break downs happen at the worst times.. Like,  rapid fire at Perry.. Why take a chance..??
Jerry