Scope Mount Side Problems - Re: Tap

macsailer

CGN Regular
Rating - 100%
204   0   0
I have a question regarding the receiver side screw hole for mounting a scope mount on the M14.

The head of my bolt snapped off, and was thinking of doing the following:
1) Drill out/remove the bolt now stuck in the hole using some method (most likely drill press, combined with a punch to try and rotate it out of the hole).
2) Instead of ordering a new bolt, and having to wait for a while for an expensive piece (>$20.00 from FabSports), I was thinking of tapping this hole to fit an M6 bolt (which appears as though it will fit quite well in the receiver and mount).

If I do the following, would it be possible to, at a later date, go back to the original 12-32 UNEF thread, using the appropriate tap? Would this tap have to be the same on Sadlak sells, or would a normal 12-32 tap from Brownells work in its place.

Thanks in advance!

-Mac
 
use a dremel with a fine diamond point and create a slot in the busted off bolt for a flat head screw driver to fit.... then back it out with the screw driver. My guess is your threads will be fine on the receiver if you manage to do it in this manner. Has worked every time on the few i have had to fix for guys with "armstrong" bolt tightening habits LOL
 
I am in Calgary

-Lets say, hypothetically, I get the bolt out, using the Dremel method, and I have an M6 bolt sitting here, along with the tap, AND I want to go shooting tomorrow (work with me here). I tap the receiver and mount, is there anyway to get it back to the way it once was after the fact (back to 12-32 UNEF), or am I completely screwed?
-Other than affecting potential resale values of the gun and scope mount, are there any other downsides to doing this?


Thanks for everyone's prompt replies!
 
- Center punch a guide mark on the middle of the broken bolt.
- Use a small drill bit and drill a pilot hole straight down on the mark you just punched in the middle of the broken bolt.
- After the initial pilot hole has been drilled through the broken bolt then increase the drill bit diameter a little at a time until about ⅔ of the diameter of the broken bolt has been removed.
- Tap a broken bolt remover into the hole and turn the remainder of the broken bolt out.

This is the proper way to remove a broken bolt in most situations of this type.

You can buy broken bolt remover sets from any crappy tire store, a these sets are a good investment to have for these situations.
 
I hate broken bolt/screw extractors, They are sometimes (especially in smaller sizes such as this) alot more trouble then they are worth.

Dimitri
 
I've had better luck using left hand drills, the punch method and the drill out method to remove broken screws and bolts then I have using extractors.

Will have to try 45ACP's Dremel method however. :)

Dimitri
 
lay some hockey or eletricians tape all around the hole to prevent marring the reciever with any method you choose.

while in a perfect world, if you have a good drill press with zero run out and a nice level bed, some good sharp drill bits in the appropriate sizes AND that easy out busted bolt/bit remover for the bolt in question... then this would be a great way to go.

I have all these things and would use them if faced with the same predicament...... average joe may not , but if a careful hand is used and you don't go any larger than you need, and stay clear of bumping the bit into the threads as you go...... creating a good slot for a 1/8 inch wide screw driver is pretty easy for the layman to do ;)


I have also been using this same method to dremel the slot deeper on the norinco receiver's silly little "barrel retaining" screw, creating a much more positive screwdriver bite for removing that pesky screw during rebarrelling.
again a very careful hand is required...... I've done more than i can count this way.
 
Last edited:
also just noticed on fabsports(.ca) site that he lists both the tap and the bolt for fixing up your receiver when you get the snapped one off
 
Don't switch to M6 with any hope at all of being able to later tap it back to 12-32. There will be little left of the threads, and once those are gone, a repair is going to be a lot more difficult. With no tension on the bolt anymore, it should rotate more easily than it did before tightened down. I'd do the cut a slot method. Use a quality screwdriver, and grind to fit, if necessary.
 
bolt

just center punch the bolt then drill it with a left hand drill bit. doing this two things will happen the bolt will heat up a little and come lose and it will back out when drilling all on its own .
 
Back
Top Bottom