View Full Version : scope base screw broken off in receiver, need help..
August 12, 2010, 04:52 PM
Does anyone have any suggestions on getting a broken screw out of the front receiver ring on A Remington bolt gun without mucking up the threads? A friend was putting on a scope base and broke off one of the screws...:eek:
August 12, 2010, 05:19 PM
Smack the friend in the face with the wadded up copy of the gunsmiths invoice.:cool: If he don't like that give em another one!:mad: just kidding he probably had the best of intentions :o This can be done, but it could be totally botched if not done carefully. Have you ever extracted a broken screw? I would take it to a smith. ;)
August 12, 2010, 06:25 PM
First step is to try to "pick" it out.
Get a hard, sharp needle and put it in an handle of some sort.
Try rotating the screw by pushing on the outer edge of the screw with the sharp needle. Alternate around the outer edge of the screw.
If you can find a small enough one, you can carefully try a Sears-type screw extractor bit turned by hand.
This is a bit that digs into the surface of the screw as it's turned out.
If none of those work, see a pro gunsmith.
August 12, 2010, 07:08 PM
Mount and ring screws dont have to be that tight.
I used to think so, also but have backed off.
A little brake cleaner or alcohol to clean the threads and a drop of fingernail polish and they will never come out-even most big Loudenboomermags.
August 12, 2010, 09:33 PM
I broke one in my Rem 700 Ti while watching a football game...got too excited and torqued it to much:o....bottom line don't watch your home team while smithing:)....take it to a smith...cost me $25...turns out the hole was not threaded the entire length.....wasn't worth my aggravation to try and repair my own stupid mistake!!!:o
August 12, 2010, 09:48 PM
The normal practice is to drill the screw out, but note that they are hard. Some gunsmiths anneal the screw by applying heat (soldering iron or torch with a small flame) but it is better to just use a hard drill. The 6x48 screw is pretty small to be drilled for an Easy-out, but I have done it. Usually, the trick is just to center the drill carefully, then drill the screw out so there is nothing left but the threads, which can be picked out.
Note that for that kind of thing, you NEED a strong, stiff drill press, with a heavy vise, and a short thick "starter" drill. Any normal length drill will wander and mess up the threads. You also need a bit of experience, so I agree with the advice to take it to a gunsmith. You might also consider having him redrill and retap the holes to take an 8x40 screw, a better choice especially for rifles having heavy recoil.
August 13, 2010, 01:56 AM
Myself,I prefer a vertical mill for this sort of thing,Many smiths have one.The rigid,precise spindle is helpfulI would center over the screw,and use a tool called a center drill to create a small,funnel shaped hole in the scew.This gives your drill the means to stay in the center of the screw.Do not move the positioning.You need to stay over this center,Then likley the magic tool will be a left hand drill bit.It can be carefully hand ground.It is run counterclockwise.As it bites a chip,likely the screw will back out.If that fails,I make an EZ-out by grinding a tapered square shape on a hi-speed lathe bit.Use a tap wrench and back it out.A good tapping fluid will help.
The touch is a little like rocking a vehicle out when you are stuck.Just work on getting motion,reverse,etc.
August 13, 2010, 03:33 AM
Try a left-hand drill bit (http://www.northerntool.com/shop/tools/product_200384104_200384104) with a VSR drill. I've never used one on a screw that small but they work great for broken bolts in automotive and industrial applications. The broken stud will often come out on the bit while you're drilling.
August 13, 2010, 08:37 AM
Screw around with trying to get it out yourself until it is all buggered up worse than it was. Then take it to your gunsmith for him to remove...they really love that.
August 13, 2010, 09:22 AM
"Myself,I prefer a vertical mill for this sort of thing,Many smiths have one.The rigid,precise spindle is helpfulI would center over the screw,and use a tool called a center drill to create a small,funnel shaped hole in the scew.This gives your drill the means to stay in the center of the screw.Do not move the positioning.You need to stay over this center,Then likley the magic tool will be a left hand drill bit.It can be carefully hand ground.It is run counterclockwise.As it bites a chip,likely the screw will back out.If that fails,I make an EZ-out by grinding a tapered square shape on a hi-speed lathe bit.Use a tap wrench and back it out.A good tapping fluid will help.
The touch is a little like rocking a vehicle out when you are stuck.Just work on getting motion,reverse,etc."
My thoughts exactly.
August 13, 2010, 06:14 PM
If you don't have experience trying to get out broken screws or taps,,,,then don't try,,,leave it alone. If you can't turn it by hand then take it to someone who has experience getting them out. If you don't know what you're doing, you will make the pro's job harder & cost yourself more money.
August 13, 2010, 07:35 PM
EDM equipment would work if you can find someone to do it .
August 14, 2010, 03:16 AM
I thought about this a little more today.Here is the deal.If you are perfectly centered over the axis of the screw,no problem with the mill and center drill idea.If the screw holds still,does not rotate,you will have no problem.If you are a touch off center and the screw rotates as you are center drilling it,you will snap the tip of the center drill off.That can be very bad.Then you may need the EDM option mentioned.
In retrospect,a spotter drill is stronger,and has no tip to snap off.Even a small ball mill would create a spot to carefully start a left handed drill.
I now recomend not using a very small center drill.There is a center drill 5/16 in dia,with a point af an acceptable size to just enter the point into the screw..That will start your drill.It will be strong enough to not break.
August 14, 2010, 05:10 AM
I've done them on a mill and a drill press.
every time i've finished I run a bottoming tap in to clean up.;)
August 14, 2010, 01:35 PM
I touch the broken face with an end cutting mill to create a flat spot as close to the center as possible, then carefully center punch dead on (transfer punch) and drill out with a left hand bit.
A firearm is far from the most expensive thing I have removed a broken fastener from.
I have a set (number, letter, and a few larger) of solid carbide left handed bits.
They are short and as hard as you would expect.
No idea if they are even made anymore.
EDM works well, but the equipment is very expensive.
August 14, 2010, 06:46 PM
I had this happen only once, thank goodness. But, I sharpened a scratch awl to a needle like point, then used a tack hammer to gently tap it ccw and it came right out. If the threads are not bottomed out there shouldnt be much resistance to turning.
If it came to needing to drill, I think I would save that for a smith!!!!
August 14, 2010, 07:18 PM
No question that a mill is better than a drill press, if one is avalable. I was more concerned with getting across the idea that a quarter-inch hand drill just won't do the job.
August 15, 2010, 10:44 AM
Dfariswheel ; First step is to try to "pick" it out.
This has always been my first pass on addressing a problem like this. You might be surprised just how loose these screw can get, once the head has proken off and the only contact pressure, is the thread contact. There are other ways to do this but basically, it's picking with sharp point or points, working together.
If one has a headache, first try and aspirin. ..... ;)
Be Safe !!!
August 17, 2010, 02:13 AM
Agreed on the picking thing.It does work often,as the loads are gone when the head pops off,so long as it was not forced into a hole with insufficient thread depth.When it works,you may find yourself picking and grinning
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