Help with scope base

steve1973

steve1973

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Hi guys,

I am wondering if I can get some ideas how to fix one of the screws on a two piece scope base that I have. I got the rifle drilled and tapped at a local smith and have been shooting it but I have noticed that the screws are loosening themselves from the recoil. I have been handtightening them to make sure the bases are solid before shooting. I decided that I am going to blue loctite them to avoid this in the future.

My problem is that one of the screws on the front base just turns free now and is not grabbing the thread on the reciever. It used to but now doesn't. I tried a different screw that tightens correctly from the other side and no dice, so the screw itself is fine and isn't stripped. Any ideas on how to fix this without redrilling a larger hole? With the other side tightened, the mount is solid so could I just loctite them both to prevent them from moving? Any advice from you pros would be appreciated!! :redface: :)
 
You should have taken it back to the 'smith the first time they loostened off. He should have loctited them to begin with...there is an oversized 6-48 screw avail, but it requires the proper tap to open the threads up accordingly....sounds like you need to visit the 'smith again....
I suppose you could just loctite it in place and hope it holds, but I'm thinking it needs re-tapping.....
 
Retapping with a larger bolt, best solution. If you have access to a tap and feel confident in using it, going to a slightly larger metric or #8-32 bolt will work. You can open up the holes at home using a drill press and proper size drill bit. The drill will follow the existing hole. Just clamp the action down tight and true to the bit. You can then hand tap.

Not a bad switch as getting these goofy gunsmith bolts is a royal pain. Switching to standard machine threads does the same job and you can get replacement bolts (usually stronger too) just about anywhere.

Epoxy screw in place. There are rethreading grades of epoxy you can get at Cdn Tire. Mickey mouse but can work if the glue holds. better then 50/50 on that.

Blue loctite would have been the best way to go initially. Make sure the screw and hole is very well degreased (I use aerosol brake cleaner, protect the stock and scope). The cutting fluid is amazing at sticking to the metal. If there is any of this stuff in the hole or thread, no sticky, lotsa loosy, drive you nuts.

My thought is that since the action screw hole stripped so easily, the size of the hole was likely on the big side for that thread. Odds are running a #8-32 (I think M8 metric tap is also close and might just be the next size up from the #6 size) tap down that hole will result in a nice hole with lots of thread. Just be careful not to overdo it and break the tap in the hole.

Jerry
 
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retapping to bigger size

8-32 is a coarse thread; 8-36 would give you more treads and more threads engagement in the receiver , m8 is 5-16" in diameter ????? also 8-40 is a size used in the firearms industries ex, marlin 336 ,1895 some remington
rifle Bob
Not a bad switch as getting these goofy gunsmith bolts is a royal pain. Switching to standard machine threads does the same job and you can get replacement bolts (usually stronger too) just about anywhere.

Epoxy screw in place. There are rethreading grades of epoxy you can get at Cdn Tire. Mickey mouse but can work if the glue holds. better then 50/50 on that.

Blue loctite would have been the best way to go initially. Make sure the screw and hole is very well degreased (I use aerosol brake cleaner, protect the stock and scope). The cutting fluid is amazing at sticking to the metal. If there is any of this stuff in the hole or thread, no sticky, lotsa loosy, drive you nuts.

My thought is that since the action screw hole stripped so easily, the size of the hole was likely on the big side for that thread. Odds are running a #8-32 (I think M8 metric tap is also close and might just be the next size up from the #6 size) tap down that hole will result in a nice hole with lots of thread. Just be careful not to overdo it and break the tap in the hole.

Jerry[/QUOTE]
 
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