Im having a moment, but I suspect that it can be done. Can an 8x32 scope base hole be opened to 8x40? Its on a el cheapo pistol with a scope base.
Gunsmithing 8x32 screw holes opened to 8x40?
- Thread starter deadly0311
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You might be saying ( Re-Tapped / threads ) ???
from - 32-threads per inch -to- 40-threads per inch . ?
If your were going #6 to a #8, that would be opening it up .. But a #8 size, to a #8 is not opening-up .
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#29 drill for the 32 pitch. .136" you can use this fo a 40 pitch as well. ID of tapped hole major stays the same. Problem is pitch. 32 pitch is .03125"/rev. 40 pitch is .02". A .0125" difference in pitch means threads are going to run over each other. Youll end up with partial threads over most of the hole. Might get the job done, but itll likely chew itself up over time.
Good luck.
C.
Good luck.
C.
You might get away with it, but I suspect you'll end up with at least one of two problems:
1) Having the two thread patterns overlap means that getting the screws started properly could be a real SOB. With my typical ham-fisted approach, I'd probably end up cross-threading it on the first attempt and make a real mess of the whole thing.
2) Having a partial thread pattern means you might rip out the screws over time due to recoil. This depends upon a lot of factors, but a heavy-recoiling round combined with a heavy scope can put a lot of strain on the mount screws.
What are you attempting to accomplish by changing the screw pitch but not the diameter? Knowing this might assist in providing an alternative solution.
1) Having the two thread patterns overlap means that getting the screws started properly could be a real SOB. With my typical ham-fisted approach, I'd probably end up cross-threading it on the first attempt and make a real mess of the whole thing.
2) Having a partial thread pattern means you might rip out the screws over time due to recoil. This depends upon a lot of factors, but a heavy-recoiling round combined with a heavy scope can put a lot of strain on the mount screws.
What are you attempting to accomplish by changing the screw pitch but not the diameter? Knowing this might assist in providing an alternative solution.
I don't think that what you are tying to do would be worth it. Your major diameter will be the same with just a tiny bit of increase in your minor dia. If you are going to go through this much work why not increase to a #10 screw and clean everything up and have fresh steel to cut new threads into. Jeff.......................
