Any help/suggestions/info appreciated

Hi all,

Been trying to find the sight set up that works best for me on my Marlin 1894 for a while now. Swapped out ghost rings, pic rail with optic, etc. Landed with a high viz fiber optic set up that works great and isn’t too complicated. Anyway, in the process I managed to mess up one tap hole on top of the receiver and now the little fill screw won’t get more than 3 rotations deep.

Was thinking that the only way to remedy the situation was to drill out the hole a tad bit bigger to remove the threading, tap it again a size up and replace the screw. If there are any other suggestions, I’m all ears. I’m not all that excited about the prospect of doing further damage to this beautiful rifle. So this is where some fun YouTube videos come in.

Video shows how to do it, but user has an impact drill set a low torque setting. I have a drill, it’s not an impact driver but still has torque settings. I don’t have much experience doing this… actually none, have always just used the drill setting for everything. Hehe. Any suggestions or advice?

Second off, if this is the way to go, should I look for a particular quality of tapping bit, made from specific material, or brand with good rep? I do have a drill press and multiple vices.

Just kinda making use of all resources and references here. Figure I can practice a few holes on scrap metal, but will only get one solid go at it. I suppose I could hunt down a gun smith and pay them $50 just to do it, but the last time I took a gun to a smith for “something simple” it wasn’t a great experience. Anyway, thanks for any suggestions or advise, I appreciate it!
To learn, you must be willing to challenge what you currently hold to be true. :crazy:

Re: Any help/suggestions/info appreciated

3 rotations deep implies the threads in the receiver got buggered up which is way better than having the screw spin endlessly (fully stripped threads).

I would chase the current threads with a thread cutter if the same diameter and hope it cuts into the original channels to be able to screw in the current fill screw flush. Maybe someone could jump in and suggest whether this would be worth paying for the experience of an actual gunsmith.

At any rate I believe it’s not worth cutting a larger diameter screw hole in the receiver just so you can put in a new fill screw… And wouldn’t that one screw also possibly look a bit “off” visually compared to the others?
"It is better to be violent, if there is violence in our hearts, than to put on the cloak of non-violence to cover impotence. There is hope for a violent man to become non-violent. There is no such hope for the impotent." -Gandhi

Re: Any help/suggestions/info appreciated

When you say impact drill, do you mean hammer drill or impact driver? Are these hand held tools?

I know this is a metric set and you need SAE, just to show the tool used for correcting dammaged or incomplete threadsd holes. ... 9791912391

I've just never heard of an impact/hammer drill press so that's why I ask if handheld. I would agree with above posts on attempting to re-tap before going larger. Low RPM, slow feed, plenty of cutting fluid, rather than torque. When Thread cutting(tapping) no powered tools, hand only, but a drill press, turned manually will hold tap true.

Good luck. You're braver than I am.

Re: Any help/suggestions/info appreciated

If you can find the size of the screw, you may be able to find the right size Heli-Coil -- it would be small. The a new "original" screw would fit and look right. You may want to use red threadlock on the helicoil itself, and then bluing on the coil so you don't have something so obvious.. I have the split Picatinny rail on my 1894, but I didn't have the screw problems. With the split rail, the iron sights are still usable, then you can mount whatever glass/optic suits you.
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