Broken scope base screw

[ArtinNC]

I have a broken scope base screw , must have been put in with lock tight . I have drilled a hole thru the screw but the bit run off a little . I tried a easy out but it will not budge . And don't want to miss up the threads . This is on a Ruger mounted scope base .

 

[AlNyhus]

No machinist, here...hell, I'm barely a machine operator. But on the couple I've had to do, I set it up in the mill, used a pin gauge to center in the hole, warmed the area up good with a heat gun to loosen any locking compound and went in with a 7/64" carbide end mill. In both cases, a sharp dental pick screwed the remaining bits of thread up and out of the hole. Maybe I got luck twice?

Drill bits are bad, bad ju-ju with stuff like this.

Looking forward to how the real deal guys deal with this.

 

[Greg@wfcustom]

No machinist, here...hell, I'm barely a machine operator. But on the couple I've had to do, I set it up in the mill, used a pin gauge to center in the hole, warmed the area up good with a heat gun to loosen any locking compound and went in with a 7/64" carbide end mill. In both cases, a sharp dental pick screwed the remaining bits of thread up and out of the hole. Maybe I got luck twice?

Drill bits are bad, bad ju-ju with stuff like this

Looking forward to how the real deal guys deal with this.

^^^^^^^^ This!!
Carbide end mill of the appropriate size (undersized) and fish the remaining “mini-springs” out.
But I probably wouldn’t qualify as a “real deal” guy. Just someone who has had to do it a few times over the years. LOL
G

 

[Krogen]

Try the easyout again, but first apply some heat to the screw. If there's Loctite in there and depending on which "flavor" it is, heat will soften it. Henkel recommends 250C for Loctite 222. A soldering iron is good for this.

"In rare instances where hand tools do not work because of excessive engagement length, apply localized heat,approximately 250 °C to nut or bolt. Disassemble while hot."

 

[Sniperhandle]

Try the easyout again, but first apply some heat to the screw. If there's Loctite in there and depending on which "flavor" it is, heat will soften it. Henkel recommends 250C for Loctite 222. A soldering iron is good for this.

"In rare instances where hand tools do not work because of excessive engagement length, apply localized heat,approximately 250 °C to nut or bolt. Disassemble while hot."

This is good advice, Use an ez out after applying heat, Use a propane torch.

 

[ArtinNC]

I'll try again tomorrow , Thanks for the advice .

 

[tobnpr]

I have drilled a hole thru the screw but the bit run off a little

#6 or #8? Takes a skinny 1/32" bit to almost match shank diameter of a #6.
Smallest EZ-Out is for 3/32". I see no way to remove it with a screw extractor.
Without knowing what you started with, or even what you have "left" not sure what I'd do, pic would help.

Busted off HSS taps are easier, they'll shatter in the hole.
If there's enough shank sticking up for a weld, I'll MIG/TIG onto the end to have something to grip.
Absent any way to remove, I'd try to punch what's left of the screw straight through (pulling the barrel if needed). It's impossible to use a pin gage to locate the hole for drilling out with an end mill because it's filled with a screw...
Punching the screw through will destroy the receiver threads, so I'd then use a pin gage to locate and enlarge all the screws by one size and modify the rail the same.

 

[round]

I have a broken scope base screw , must have been put in with lock tight . I have drilled a hole thru the screw but the bit run off a little . I tried a easy out but it will not budge . And don't want to miss up the threads . This is on a Ruger mounted scope base .

Can you post a photo ?

 

[AlNyhus]

It's impossible to use a pin gage to locate the hole for drilling out with an end mill because it's filled with a screw...

On the ones I did, the scope bases were still on...just one screw head was snapped off. A pin gauge in the base screw recess got the end mill centered up.

If the base is off, a pin gauge in the other screw hole and moving the correct amount to the broken screw should do the trick.

 

[tobnpr]

If the base is off, a pin gauge in the other screw hole and moving the correct amount to the broken screw should do the trick.

Yep. I assumed the OP wasn't using/doesn't have a mill and is using a drill press... otherwise why not start with your course of action- locate the "good" hole, move to the busted one and use an end mill to drill it out?

 

[ArtinNC]

Here is a picture , NO not going to use s drill press . Have to find someone that has a mill . I guess . I have all ready scratched it up . and don't want to miss it up any more . I got three out with a easy out , Ruger must have used lock tight .

 

[Krogen]

I don't see any evidence of Loctite in the hole where you removed the screw. Chances are, there's none in the recalcitrant one. I thought you'd tried getting the troublemaker out with an easy-out. It doesn't look like it.

 

[ArtinNC]

I don't see any evidence of Loctite in the hole where you removed the screw. Chances are, there's none in the recalcitrant one. I thought you'd tried getting the troublemaker out with an easy-out. It doesn't look like it.

Every screw was striped and had to use the easy out to remove the screws and this last one the head of the screw broke off . Yes I cranked pretty good on the easy out and it didn't budge .

 

[WSnyder]

Mill or find someone with a bolt burner. I want to see someone attempt to MIG a head on a #6 screw.

 

[ArtinNC]

Didn't work on it a couple days , went out this morning put the easy out in and it come right out . Some times you just need to take a break . Thanks for all the comments .

 

[DaveTooley]

On a through hole, most of the time a center drill will break it loose.

 

[AlNyhus]

On a through hole, most of the time a center drill will break it loose.

Thanks for the tip. Dave. Will try that the next time I have to do one...which is hopefully never again.

Good shootin' -Al

 

[Keith Kilby]

I spot with small center drill then drill with smaller than tap drill size….little bit of room for error. As Mr. Tooley stated, many times once the twist drill “grabs” it will chase remnant right out if it’s a through hole. Since the drill was smaller than tap drill size original threads are safe. For blind holes I use the same sequence as above but instead of ez out, I’ve had much better results with torx bits. Pick a drill size that requires the torx bit to be lightly driven in. Not how tool and die guys likely were taught but has worked for me for years.

 

[DaveTooley]

I spot with small center drill then drill with smaller than tap drill size….little bit of room for error. As Mr. Tooley stated, many times once the twist drill “grabs” it will chase remnant right out if it’s a through hole. Since the drill was smaller than tap drill size original threads are safe. For blind holes I use the same sequence as above but instead of ez out, I’ve had much better results with torx bits. Pick a drill size that requires the torx bit to be lightly driven in. Not how tool and die guys likely were taught but has worked for me for years.

Even a small jewelers screwdriver works