Third Party Press

Lock screws - cross threaded sh!tshow fix

Hambone

Hambone

Community Organizer
Staff member
Break off a lock screw trying to install it one time and and you'll (hopefully) never do it again. It's easy to do. These little bastards get cross threaded, or if the head hangs up on the action screw or edge you can torque it off, easily, leaving the headless screw in your lock screw hole. The solution is to STOP when you hit resistance. Nothing should be forced. Clean out the screw hole with a brush, q-tip (don't leave fluff in there), ballistol / clp, and clean again. If the lock screw still won't go in, on its own, with the correct angle, chase the threads with this. It's cheap. Go slow, clean out the shavings, preferably with compressed air:

98k Lock screw die.jpg

Remember, remove the triggerguard and all screws but the one you are working on. MAKE SURE YOUR ANGLE IS CORRECT, GO SLOW, DON'T FORCE ANYTHING. Also, the early notched lock screw is supposed to stay in the triggerguard, turned to "open" so that the action screw can be removed. Don't ask me how I learned this lesson long ago.
 
Best to start a screw in reverse til it drops in. Especially important with plastic threads. Also use gunsmith screwdrivers. Locks in better and tip is designed to break before damaging screw.

Sent from my Pixel 4 XL using Tapatalk
 
capt14k said:
Best to start a screw in reverse til it drops in. Especially important with plastic threads. Also use gunsmith screwdrivers. Locks in better and tip is designed to break before damaging screw.

Sent from my Pixel 4 XL using Tapatalk
Click to expand...

Good advise but even a good gunsmith screwdriver or bit won't break before a lock screw does.....
 
I had a scare a while back...thought I broke the head off a capture screw on a rifle. Thankfully it was just seized in there from 75 + years of crud. Definitely puckered up when I heard that snap... I try to drop a little bit of kroil on them now to help removal.
Have gotten in the habit of not tightening the action and capture screws on K98s I dont intend to fire. I just make sure everything is seated and just snug them.
I am going to pick up a tap now that I know the thread pitch.
Thanks for all the good advice.
 
CE43 said:
I had a scare a while back...thought I broke the head off a capture screw on a rifle. Thankfully it was just seized in there from 75 + years of crud. Definitely puckered up when I heard that snap... I try to drop a little bit of kroil on them now to help removal.
Have gotten in the habit of not tightening the action and capture screws on K98s I dont intend to fire. I just make sure everything is seated and just snug them.
I am going to pick up a tap now that I know the thread pitch.
Thanks for all the good advice.
Click to expand...

Good advice as well!
 
Screwdrivers

My son got me the Brownells screwdriver set with two handles and exchangeable tips. I can't say how much time and energy the thing has saved me. You can get the exact size slotted driver that fits all the way in the bottom of the slot. Expensive but, worth it.
 
casca47 said:
My son got me the Brownells screwdriver set with two handles and exchangeable tips. I can't say how much time and energy the thing has saved me. You can get the exact size slotted driver that fits all the way in the bottom of the slot. Expensive but, worth it.
Click to expand...

Absolutely it is. This is the set I've had for about 20 years. It's not even the highest quality, but it's plenty good enough and will save buggered screws. It also has the 98k recoil lug spanner and other specialized gun tools. No reason not to have a set like this.
https://www.amazon.com/Wheeler-Engineering-Gunsmithing-Screwdriver-Construction/dp/B001C63M7O

Check out your boy:

 
Hambone said:
Break off a lock screw trying to install it one time and and you'll (hopefully) never do it again. It's easy to do. These little bastards get cross threaded, or if the head hangs up on the action screw or edge you can torque it off, easily, leaving the headless screw in your lock screw hole. The solution is to STOP when you hit resistance. Nothing should be forced. Clean out the screw hole with a brush, q-tip (don't leave fluff in there), ballistol / clp, and clean again. If the lock screw still won't go in, on its own, with the correct angle, chase the threads with this. It's cheap. Go slow, clean out the shavings, preferably with compressed air:

View attachment 230383

Remember, remove the triggerguard and all screws but the one you are working on. MAKE SURE YOUR ANGLE IS CORRECT, GO SLOW, DON'T FORCE ANYTHING. Also, the early notched lock screw is supposed to stay in the triggerguard, turned to "open" so that the action screw can be removed. Don't ask me how I learned this lesson long ago.
Click to expand...

I used to run the tap from the back side of the triggerguard when I could. I often found a broken off lock screw was rarely removable with an easy out of left twist drill bit. I step drilled them out until I oculd see "ghost" threads then peeled out what I could with a fine pick. Then gentle nudges with a tap from the opposite side of hole when I could. Pain staking process , but patience and some beer got it done more often than not. On two guards I had to drill out threads completely and tap for a larger screw . I took the screw and drilled it out and tapped for lock screw and screwed it in place and set with 609 Loctite and cleaned up with a carbide end mill dremel . Yeah I know that's a bit overboard but on some fine rifles - they demanded that repair to make whole again.
 
gew98 said:
I used to run the tap from the back side of the triggerguard when I could. I often found a broken off lock screw was rarely removable with an easy out of left twist drill bit. I step drilled them out until I oculd see "ghost" threads then peeled out what I could with a fine pick. Then gentle nudges with a tap from the opposite side of hole when I could. Pain staking process , but patience and some beer got it done more often than not. On two guards I had to drill out threads completely and tap for a larger screw . I took the screw and drilled it out and tapped for lock screw and screwed it in place and set with 609 Loctite and cleaned up with a carbide end mill dremel . Yeah I know that's a bit overboard but on some fine rifles - they demanded that repair to make whole again.
Click to expand...

All of this. If you've got too much metal in the threads the tap is going to bog down and cause problems. So it's pick as much as you can and go slow. High pressure air can help.
 
You must log in or register to reply here.

Military Rifle Journal
Back
Top