https://thegreatmodel8.net/

I'm sure I'm not the first one to encounter this problem, but it seems that the main stock screw is rusted in place on my Model 81. I have been using rem oil and wd40 to try to get the screw to turn, but no luck. I don't want to booger the screw head. Any suggestions? I'm using quality gunsmithing screwdrivers too. I don't think the screw has been out of the rifle in 70 years. Thanks.

Apply a good penatrating oil and let soak in. Get a perfect fitting screw driver. With the screw driver in the screw slot hit the head of the screwdriver with a hammer at a rapid pace while turning the handle.

Another idea would be a heat gun. After you empty the mag.
I'm assuming the screw you mentioned is the one in the left side of the receiver, not the one thru the butt stock.
If in the stock, if a low number serial ####, I have this suggestion:
Remove the screw in the left side of the action just above the trigger.
Drive out the hammer pin that goes thru the trigger guard and the receiver.
Get a long clamp with plastic protector pads, and apply pressure from the top of the butt to the front of the action. You will have to pull the barrel assy to do this. Reason: some of the early stocks for the 81 may have been drilled a little shallow for the action spring tube and plug. I had this very problem with 2 XXXX 81s.
Removal of the screw, pin, and clamping front to buttplate may relieve side pressure on the screw. Pray the last guy that put the screw in did not damage the threads. I have researched for the tap & dies for these with no results at all. It would help members greatly if one of us knew the thread size and pitch. We should be able chase threads without damage to condition.
If this is the root cause I also recommend judicious use of a flat bottom auger to give the action tube a little more room. Drill only enough (By Hand) so the action seats all the way in the stock. A little goes a long way.

I used some catalyst spray (many times) and the tapping method with a good screwdriver, but the stock screw is not moving. Man, this one is in good.

Which screw are you talking about. The one that goes in the bottom tang through the stock? If you have access to a large drill press you can lock the gun in so the screw head is under the chuck. Fit a correct screwdriver in the chuck and lower the chuck so the screwdriver goes into the screw head. Lock the chuck down. Insert a rod in one of the chuck holes and twist the chuck. Do not use the motor just turn by hand. Remember the screw has to back out so do not put a lot of down pressure on the chuck. This has alway worked. The screw will come lose or you will twist the head off. If this does not work then the only thing left is to center punch the screw and drill it out. If you are talking about the screw that goes through the wood most likley the wood has swelled putting pressure on the screw. I have had a few that were very difficult to remove and only brut force got them out. Hope you get it out.

Its the stock screw - not the receiver screw.

Thanks for the help, still no luck. It even broke the tip off one of my quality Grace screwdrivers. Wow!

Get a very large screwdriver and grind the tip to fit. Get a friend and one apply down pressure while the oter turns the screwdriver. If you can get screwdriver with a collar for a wrench that will help turning. The wood is applying pressure to the screw. I have had them very tight.

Try using beeswax. Yep. Warm the parts with a heat gun and work a small bit of beeswax (no imitations) around any seams or cracks between the two parts. Let cool completely. Do it again. Beeswax is an amazing penetrant. It won't make things easy, just easier.

Todd,

All the suggestions so far have merit. The beeswax sounds interesting.May have to try that sometime. Working on old ones you are gonna find some that will not budge no matter what. Good on you for using proper screwdrivers but youve found out why they don`t guarantee them..They are hard but brittle.
When I`ve had the really stubborn ones have used a homemade penetrant; 50/50 mix of acetone and automatic transmission fluid. Shake it well and apply liberally .Next step will require sacrificing a screwdriver. With the one that fits the slot perfect cut the shank leaving enough to chuck into a drill press. Secure the stock with a jig or padded vise and be sure the chucked screwdriver blade is square to the screw. This sometimes is a two man operation with one applying downward pressure and the other turning the screw driver. With Grace the flat sides help and are easy to grab with vice grips. Good Luck !
Joe

This is one VERY handy tool for stubborn screws.

http://www.ebay.com/itm/3-8-Manual-Impa ... SwuYVWpyoX

It has cam pins in it similar to the cam action of the Remington model 8/81 bolt carrier. You can change from loosening mode to tightening mode. If in loosening mode, you would apply counter-clockwise pressure on the tool and then hit the head with a hammer. Lightly at first, but increase the blow until the screw loosens. It is applying impact, inward pressure and counter-clockwise torque all at the same time. The screw will come out or the head will twist off. This also does not damage the screw slot.

ROB

This is a very effective screw impact driver, just be very careful it doesn't jump out of the slot. It also is a good chisel on blued surfaces.
I've an old one by Craftsman and a Irwin adapter for screw bits. It's so stout I've broken several bits already.
Before using the impact route I usually try my Chapman set with the mini ratchet; part in a padded vise, the tight fitting bit in the screw, the ratchet on the extension that comes with a gunsmith set, and the screwdriver handle on the back. This set up has twisted the head off many a screw head.

https://chapmanmfg.com/products/master- ... cqEALw_wcB

Tip: file or grind off the stop dimples on the extension to allow the ratchet to slide down the shaft to the bit end.

One of my other diversions has me working on old hit n miss engines. I was pondering a bolt that hadn't seen daylight since 1903 when an older fellow suggested the beeswax thing. Now there's a pound of the stuff on my bench.

BZimm

Sooooooo........Todd.....Did ya ever get it out ?
Joe

Hey Sarge -- I had to bring the rifle to my gunsmith. He was able to do some magic that finally loosened the screw and he didn't bugger up the screw head too badly (I bought a new screw anyway). It was rusted in place and was untouched for probably decades.

While we are on the topic, any advice on how to remove the hammer pin that won't seem to move in the least bit? Its the pin that goes through the receiver and needs to be tapped out. I never had this problem before with my other rifles, but this new purchase M81 hasn't been taken apart in many years and the pin is just not moving.

I have tried to soak it in Kroil for the last few days and still no movement.

Thanks,

Todd