Gunsmithing need help with broken scope base screw... am I out of options?

P

Putz7mm

Private
Minuteman
Jan 30, 2019
8
2
#1
First time poster in a bit of a pickle...

I have a broken scope base screw that is really stuck.... I tried everything I have seen... heat and oil, micrograbit, drilling out (but its over the barrel), and epoxying an allen wrench to it. I gave it my best shot and then took it to a gunsmith before messing up threads... gunsmith states they have tried and can't get it out. They want to tap it for an 8-40 screw, which I really dont want to do. Its a Sako and it is my most expensive rifle. I don't like the idea of having one larger screw in my bases (yes, I am really particular). I have thought about having them do all the holes to 8-40, but then I have to deal with drilling larger holes in the bases (I think). I don't want to epoxy my bases to the rifle either.

I have thought about having them remove the barrel and drill through the screw. I am concerned this will mess up the barrel threads.

I am hoping someone on here has a good suggestion... but starting to worry I am out of options. Pretty bummed to have put myself into this situation.

Do I have any other options or things to try?

Thanks
 
  • Like
Reactions: Mike916
#4
You broke the screw. You said that. You did your due diligence but now you can't find a solution you like. You could file it off and shoot without the base screw. You could sell it and let the next guy deal with it. You could let the 'smith drill and tap it to 8x40 and drill and ream the base - this is the right answer. It will be a lot easier and safer if he also pulls the barrel before drilling out your screw-up. Drill and tap isn't going to mess up the barrel threads.

It's a rifle, it's a tool, relax, let your 'smith fix it the right way and get back to shooting. Worse things will happen to you. You can't change the broken screw, don't let it ruin your day.

BTW, I bed all of my scope bases. I don't use the screws sent with the base. I take longer screws and file them until each one fits perfectly when under proper torque. I use a small torque wrench to tighten the screws 12 to 15 in-lbs then loctite. Some of mine are 8x40 some are not, this is not something to worry about.

[edit] You could find a shop with an EDM machine and arc that little devil out of there. Take money. I did that once with a bullet stuck in a point up die but the guy who did it was the night shift shop supervisor, it was off hours, and he was showing off for me so it was free. If you can't get an EDM machine, use more average methods.
 
  • Like
Reactions: Charlie-Hotel-Six and goatboy
#5
I ran an ainchant edm a royal pita.
Dialed in perfectly center under a bath of oil a receiver with out a good holding fixture. An art in itself.

Not sure who would take it on.
Unless they have a license you have to be there.

Go with the 8/40 and carry on.
 
#6
Is the base off the receiver? Step one drill the head off the screw. Step 2 pull the rail. Step 3 pull the barrel. Step 4 drill or mill the center of the screw out. Step 5 use easy out or equivalent to remove outside of screw. Step 6 chase threads with current size tap.
If that doesn't work then give them all the 8-40 treatment.
 
  • Like
Reactions: Sam Dunham and ugsly308
#7
Will removing the barrel mess up the barrel threads? I’m concerned the screw is pushing on those threads... but I have no way to know that.

I will look into edm. Thanks for the tip.
 
#8
Also, yes the bases and head of the screw are off. The gunsmith hasn’t removed the barrel.

Also, the screws were stock Talley screws so it’s possible they aren’t long enough to seat on the barrel.

I am no gunsmith... have never removed a barrel so really don’t know how deep the threaded portion goes or if threads are exposed to the base screw hole.
 
#9
Not a method may people know. I.hated the edm a lot.

An old style air powered vibration engraver. I don't like the electric. Put the tip on the screw angled ccw and tilted in to center .
Apply a drop of alcohol or mek, thin tapping fluid.

Push down and ccw firmly, turn tool on slow. Put varying amounts of pressure on it staying away from hole. Adjust pen speed a little at a time so not let it walk against receiver.

Vibration sucks the liquid in and breaks the seal, may have to go back and forth
Once loose just vibrate out.
Works best on broken taps.

Saved many expensive parts like that.

Drilling is the next step if it don't work.
 
#10
Putz7mm said:
Also, yes the bases and head of the screw are off. The gunsmith hasn’t removed the barrel.

Also, the screws were stock Talley screws so it’s possible they aren’t long enough to seat on the barrel.

I am no gunsmith... have never removed a barrel so really don’t know how deep the threaded portion goes or if threads are exposed to the base screw hole.
Click to expand...
With everything that has been tried I think you can assume the screw is hard into the barrel threads. That probably contributed to breaking the screw. It acted like a jam nut.
It sounds like a carbide end mill and a very rigid setup are needed. Plunge in then pick the pieces out. Clean up the threads with a tap and you should be good. Good luck.

Dave
 
  • Like
Reactions: Ksracer, kortik and Blair B
#11
If you think it is touching the barrel the same steps I described will work just use an end mill like dave said. A little calculation should tell you how far in you can go. I would probably try to mill down about .010-.020 past the major diameter of the barrel threads since the screw would have hit on the peak of threads and maybe rolled them over slightly. .020 should be plenty to clean that up. Then use the next smaller tap drill for your current threads to drill as much of the screw out as possible the outside part of the screw will probably unwind like a slinky at that point. Then clean up with the appropriate bottom tap.
 
#13
I had a screw break in a scope ring.

Couldnt get it out.

Took it to a shop that does micro welding.

They welded a stud on the remains of the screw.

10 mintes work cost me $10.00 and saved my Badger M40 repro setup.
 
#14
Pic before gunsmith got it.
 

Attachments

  • BE60D288-62DC-4991-A425-433A0AF0BD7B.jpeg
    BE60D288-62DC-4991-A425-433A0AF0BD7B.jpeg
    326.2 KB · Views: 286
#15
This one is after the gunsmith. They bored out the hole and boogered up the receiver. No stoked.... how to handle it?

May just make all the holes #8 so they match for my perfectionism side....
 

Attachments

  • B9C59EB8-E117-40E7-A700-0E9B5605AA3C.jpeg
    B9C59EB8-E117-40E7-A700-0E9B5605AA3C.jpeg
    322.5 KB · Views: 238
#16
Putz7mm said:
This one is after the gunsmith. They bored out the hole and boogered up the receiver. No stoked.... how to handle it?

May just make all the holes #8 so they match for my perfectionism side....
Click to expand...
I would strongly recommend taking Chad's offer from @LongRifles Inc. They have a great reputation for barrels and smithing.

There is a good reason to swap out to 8-40s: the slightly larger diameter has more strength and is less likely to repeat what you had happen. As far as bases go, it's simply drilling them out slightly larger. Chad can probably take care of that too if you send base in with rifle.
 
  • Like
Reactions: Snuby642
#18
ajwcotton said:
Is the base off the receiver? Step one drill the head off the screw. Step 2 pull the rail. Step 3 pull the barrel. Step 4 drill or mill the center of the screw out. Step 5 use easy out or equivalent to remove outside of screw. Step 6 chase threads with current size tap.
If that doesn't work then give them all the 8-40 treatment.
Click to expand...

This is the fix unless you are able to drill it out in a Milling machine to the proper depth per the length of the screw and ease it out. I would level it in the mill and center up off a pointer with the other screw hole and run the table the distance in thousands to the correct center of the bad screw and run a carbide drill starter 1/16th to the correct depth of the original length of the screw minus the point length on the CD, A reverse twist ease out that locks in the sides and tightens up spinning counterclose wise. 8-40 is superior in every way to a 6-48. I am actually a fan of a 10-32 on my rifles.OK let me tell you this' "Gunsmith comes in many forms in the use of the word. Whoever did that shit, is no Gunsmith!
 
Last edited:
#22
Putz7mm said:
First time poster in a bit of a pickle...

I have a broken scope base screw that is really stuck.... I tried everything I have seen... heat and oil, micrograbit, drilling out (but its over the barrel), and epoxying an allen wrench to it. I gave it my best shot and then took it to a gunsmith before messing up threads... gunsmith states they have tried and can't get it out. They want to tap it for an 8-40 screw, which I really dont want to do. Its a Sako and it is my most expensive rifle. I don't like the idea of having one larger screw in my bases (yes, I am really particular). I have thought about having them do all the holes to 8-40, but then I have to deal with drilling larger holes in the bases (I think). I don't want to epoxy my bases to the rifle either.

I have thought about having them remove the barrel and drill through the screw. I am concerned this will mess up the barrel threads.

I am hoping someone on here has a good suggestion... but starting to worry I am out of options. Pretty bummed to have put myself into this situation.

Do I have any other options or things to try?

Thanks
Click to expand...

Just spent $75 at a smith for the same thing.
 
You must log in or register to reply here.

Similar threads

C
Badger scope base: loctite on bottom?
Replies
17
Views
490
colt.45
C
c3guns
Murphy Precision scope mount for Anschutz 54.18MS question
Replies
1
Views
132
mikekustoms
M
L
Gunsmithing Stuck scope base screw
Replies
12
Views
1K
Easy_E
E
S
Am i wrong
Replies
8
Views
367
Megalodong
M
G
Remington 700 Clone action help
Replies
4
Views
410
Mr-Ironhide
Mr-Ironhide
Top Bottom
Back
Home
Forums
Merch
Alerts