That stubborn screw

Nabs

Nabs

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Hello CGN,

I ran into an issue the other night. I have a Gewehr 98 that has the infamous "stubborn screw". The rear trigger guard screw is in tight and despite my best efforts to loosen it, it won't budge. I suspect a combination of gunk and possible wood shrinkage are to blame. I usually can get these unstuck but this one is a first. She is one screw away from being completely disassembled for a thorough examination and cleaning.

I tried the usual tricks, oiling multiple times, letting gravity do it works to allow the oil to work its way down under the screw (from both sides), and torquing. The screw was already very lightly stripped but it can still hold a bit with a bit of back pressure so it doesn't jump out.

I have thought about taken her to a gun smith but I am curious for any other options that other CGNers have found that works.

Thanks for the help :).
 
Interesting, thanks for the idea :).

I remember seeing a trick that used a screw driver and a socket wrench during my internet research.I don't have a bench or vise grip so my only concern would be how to keep the bit in the screw head while holding the rifle and applying pressure to get it out.

As for the screw, I would like to save it if at all possible.
 
I've had great success using cordless impact drivers- the ones that take a standard size screw bit. Use a bit of valve lapping compound on the tip of the bit. It allows the bit to grip to the screw a lot more.

<-----I used this method to replace the rusty, seized fuel tank screws on this, after breaking a dozen screw driver bits.
 
An arbour press putting downward pressure on a screwdriver while it is carefully turned with a wrench will keep it from lifting out of the slot. You can also try an impact driver, the type that is hand held and struck with a mallet. A well fitted screwdriver tip is essential.
 
As a mechanic I will tell you every way to remove a screw I can think of.
is it a star (philips) or a flat blade screw?

An impact driver is the best tool for non-destructively removing screws.
2011-07-19_205403_impactdriver.jpg


You hit the end with a hammer and it turns a fraction of a rotation. The shock of the impact and the torque multiplication involved works on most stubborn fasteners.

You can use heat and quenching - although not a great idea on a wooden item.

Penetrating oil - PB blaster, liquid wrench are the best. WD40 is not. Tapping the screw with a hammer after dousing in penetrating oil will help it to work through the threads. Heat helps as well.

Destructive methods - using a die grinder burr tool, grind only the head of the screw off. This will leave a short portion of the screw shank exposed after you remove the wood, and will let you get a pair of vice grips on there to turn it out. I have used this to remove metal floorboards from construction equipment several times.

If it's a flat tip screw, you could turn a large flat tip screwdriver sideways and use the extra leverage to try to turn it out. I find using a ratchet with a bit adapter can often help provide enough "umph."

Finally, properly machined screw drivers are worth their weight in gold. Canadian tire jobmate screwdrivers are NOT machined to the right dimensions. The angles are wrong for pretty much everything, I've found.

I have a set of german Wiha screwdrivers I use for all precision work - not that the steel is much better, but because the dimensions are such that they grip screws better.

I confess that I have no idea what a Gewehr 98 stubborn screw looks like.. but I hope these tips can help you. Good luck!
 
Sounds crazy.... but I use an impact driver. I have even removed the small screw out of a Ross's front sight without any damage to it. The nano-second there is too much pressure, it gives the screw a tap. I have used it at least a dozen times without incident. Now.... never use this to put in a screw, or it will snap the head right off.

http://www.ridgid.com/Tools/R86031-Compact-Lithium-Ion-Impact-Driver/EN/index.htm

Once you use this, you will never drive another screw with a drill again!
 
Brownells sells flat blade screw drivers with the correct dimensions and thicknesses for mauser screws. They also have a hex shank so you can turn them with a wrench. They aren't very expensive and well worth the money.

Probably doesn't help you now, but just a suggestion for the future.
 
Grizzlypeg said:
An arbour press putting downward pressure on a screwdriver while it is carefully turned with a wrench will keep it from lifting out of the slot. You can also try an impact driver, the type that is hand held and struck with a mallet. A well fitted screwdriver tip is essential.
Click to expand...

A large Drill Press works well to keep pressure on the screw while you turn the chuck, but you need something to hold the rifle in position.
 
Screwdriver in the slot, smack with hammer to jar it. After that if they still wont budge, ratchet with a screwdriver bit. Once you have it apart, enlarge the hole, and put in a metal sleeve if there isnt one, a little clearance between the sleeve and the screw and usually the problem goes away. Chase the threads, a little moly is my choice, then reassemble.
 
Wow some great ideas here, thank you everyone. The screwdriver bit is flat, it is a standard style mauser rear trigger guard screw, same as you would find on a Kar98k or even a VZ24.

I have used the "manual" impact with the screwdriver in place and a wack on the end with a hammer. This worked in the past for some screws I thought were bad but this one has resisted.

I do like the idea of the impact driver and it sounds like a good investment piece. Are there any recommended brands ? My only fear is the screw head snapping off though I have not seen this happen to a mauser related screw. Does the impact hammer work on the simple principle of "Lefty loosey, righty tighty", or does it work on removal only ? How much force do you hit the impact driver with ? Would it be some light taps or a light to moderate wack ?

Many thanks for the ideas everyone, it is a great help. I hope I can have this Gewehr 98 apart soon as she calls for a good cleaning.
 
I know you have tried oiling, but have you tried Kroil?

Kroil oil penetrates better than any other oils I've tried, give it a few drops, leave over night, if still no luck then repeat a couple times.

Kroil is widely available in the U.S. but only at some gun shops here in Canada.

-Steve
 
I havent heard of that oil before, is it safe on wood stocks?

How much does it usually go for in Canada? I will check with the local gun shop tomorrow to see if they have any.
 
a lot of these sloted head screws on milsurps get thorn up because of improper screw driver bit dimater,a good set of screwdrivers are quite esential for this ,nothing looks worse than a screw whit the head slot thorn up,as to removeing this particular screw take a bit that is a little wider than the screw head slot and with a hammer lightly tap the bit into the slot ontil its in there tight .Now take your screwdriver and try and turn the screw out if you have a bit adaptor you can use your quarter drive ratchet which will give you more turning torque,hope this helpes
 
I'll add that I have used solvent and oil (alternating each day for a few days) and found that has really worked really well on those stubborn seized screws. My theory is that years of dirt and oil glue the screw and penetrating oil couldn't cut it.

If you mess the head up removing it, they are easily fixed back up using a ball pean hammer. Work the metal back down toward the groove and use a slot screw driver as a punch to form the slot straight and even after peaning. If it's rough from peaning use a fill sparingly and then emery cloth to smooth it up. A $10 bottle of cold blue cream and it looks and functions like new.
 
Most slot head screw heads are ruined because conventional hand screwdrivers have a taper toward the point rather than parallel sides. The hollow ground screwdriver inserts pictured with the impact driver have parallel sides where they engage the head of the screw. The impact driver can be reversed to tighten or loosen by turning the top one way or the other while holding the other end. Check whether it is set to loosen or tighten by tapping it on a flat metal surface like a bench or vise without a bit inserted. To use the impact driver, hold it tightly twisted counter-clockwise in the screw head, then give it a smart whack with a ball-peen hammer.
 
Impact driver for sure. It will 100% get that screw out and rarely makes it worse.

And they're cheap. You can get them almost anywhere, Canadian Tire should have one.

If you have a set of precision tips, you can put the socket on the 3/8 square drive of the driver that fits the hex shank on the bit. Works really well.


(from previous post)

An impact driver is the best tool for non-destructively removing screws.
2011-07-19_205403_impactdriver.jpg


You hit the end with a hammer and it turns a fraction of a rotation. The shock of the impact and the torque multiplication involved works on most stubborn fasteners.
 
I had the exact same problem with my bolt mismatch 1914 Gewehr98 (you know the bolt Nabs ;) ).

I tried for days with penetrating oils of all types, and with the proper hollow ground bits from my gunsmithing set.... But to no a avail... And I have never met a Mauser screw I couldn't remove... (I did have to drill out a Mosin screw once)

Finally, I took the interweb advice of using an impact driver... I was a little wary at first, but I chucked the proper Mauser bit in the Mastercrapt cheapo drill, set it to impact, and 3 seconds later I had the screw removed and was able to take apart a Gew98 that probably hadn't had that done to it since WW1!!

PS: the screw was already stripped too!!!

I love impact tools! :)
 
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Impact wrenches are the way to go!!! When used to be a mechanic if we had a stuck screw the impact always came out. my brother always says a stuck screw " needs to be woken up" which is funny but true.
 
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