HomeSmith Tuneup: A Little Harry

[Shotguncoach]

Being this is a .22 Magnum, the most powerful rimfire in the world and would blow half your head clean off, you've gotta ask yourself one question: "Do I feel lucky?"

I was feeling lucky tonight and wanted to do something fun while I waited for my Security Six special shim shipment to show.

Project name: A Little Harry

Little Harry is a 48-2 in .22 WMR that was made in 1974. It has a 6" barrel, target stocks, and a damn ugly trigger.

I knew I was going to be working on Harry soon, so during my last range trip I did a strain screw loosening reliability test. With the strain screw fully seated the hammer tension was 72 ounces. Half a turn out was 60 ounces and a full turn out was 52 ounces but that didn't matter because anything over 1/2 turn out gave light strikes. That made things simple: stay above 60 ounces with this one.

That range trip also gave me something I would need during the work: empty cases. Dropping the hammer on an empty rimfire chamber is bad juju and I didn't have any rimfire snap caps. My wife looked at me a bit strangely when I handed her 6 empty cases and asked her to verify that they really were empty. Then again, she's been sure that I'm a few bottles short of a 6 pack for a while. The empty cases were marked with a blue sharpie but unfortunately that wore off with handling. Note to self: get the right snap caps for rimfires.

The initial trigger pull tests showed 4 1/2 lbs single action and 10 1/4 lbs double action. The single action break had a fair amount of creep and the double action pull was peaky and uneven. Backing the strain screw out 1/2 turn dropped the numbers a bit to 3 3/8 lbs single action and 8 1/2 lbs double action. The peaky double action pull seemed to get worse with the screw backed out.

Help me Jerry Kuhnhausen, you're my only hope.

 

[Shotguncoach]

Harry looks pretty good on the outside but he is a poster child for "Use the right screwdriver, dammit!" I usually use a #1 screwdriver for sideplate screws but for Harry I had to dig out a #2 for the middle screw and a #3 for the mangled yoke screw. Note to self: dig through the pile and find Harry a better set of screws to be fitted.

Happily whoever mangled the screws did not also mangle the sideplate and the insides were really pretty clean. Let's move all the insides to the outside and see what stories Harry has to tell....

 

[Shotguncoach]

The first thing that started talking to me was the hammer. We've got a wear mark on the nose where it seems to be rubbing on the frame, a slight circular wear mark on the right side that appears to be from a sharp edge on the sideplate, and a straight line horizontal scrape on the left side that looks to be from the bolt rubbing when the cylinder is released.

The double action sear butted into my conversation with the hammer to tell me that it was unhappy too and needed a closer look. Ooohhhh a round head pin! Yay! I finally get to use those expensive cup tip punches I bought! And wow that is an itty bitty spring under there. Anyway...what it wanted to tell me was that it had an uneven contact patch on the front face, a truly horrible bottom surface, and uneven bottom bevel, and rub marks on both sides where it was scraping against the sear channel in the hammer.

He was one pissed off double action sear. The picture of the bottom surface was out of focus but if you go look at the sidewalk in front of your house it will have a similar surface.

Out came the stones and the double action sear got a smoothing. Getting the grooves out of the bottom surface and evening out the transition bevel took some work. It was a much happier camper when it went back together.

The hammer itself didn't get touched. I could feel a sharp edge (almost like the burr that you get when sharpening a knife) along the top of the sideplate, the top of the frame, and both sides of the frame around the firing pin. Stone stone, rub rub, gentle gentle, shiny shiny, happy happy. These areas may have to be touched again because I went with a "less is more" approach and only worked until the drag on the stone changed. We'll see.

 

[Shotguncoach]

I felt like I was getting a little ahead of myself by working on the double action sear before I finished the inspection. The hammer assembly got set aside and the gauges came out.

The cylinder gap was .006" and slightly uneven from side to side. Endshake was .002". I didn't measure the rear gauge because I simply forgot. We'll get that next time.

The yoke alignment test failed on the first try. To get it to line up, I removed the gauge pin, closed the yoke, put a hammer handle vertically on the "push from this direction" mark I had made on the yoke barrel, and leaned my upper body weight onto it. The gauge dropped into the center pin hole after the 3rd leaning. I've seen videos of people using the handle that comes with the ejector rod straightening jig to do this, but the "closed yoke" method seemed to provide more support to the yoke. If this is the wrong approach and puts the torsion in the wrong place, please throw something at me.

 

[Shotguncoach]

Next up was the ejector rod test.

The initial runout was almost .009".

After about 87 tries it occurred to me that I should mark the high and low sides of the rod. One dot for high, two dots for low. Measure, bend, measure.

The reason the rod wasn't straightening out was that I was using too much pressure and simply swapping the high and low points. The emotional support llama was disappointed.

My notes from the last (and only) time I did this showed the same thing happening. Notes only help if you read them...

Going back to the "only three fingers on the bar" method that I wrote down last time got it to .002" runout. That seemed like a good time to take a break for dinner.

 

[Shotguncoach]

The ejector rod fixture was put away and we went back to the stories the parts were telling me....

The frame had a circular rub mark just below the bolt where the edge of the trigger was rubbing after coming off of the double action sear, and the rebound slide bottom bearing surface had some uneven wear marks on it. Both areas got cleaned up with the small end of a ceramic stone.

The rebound slide was stoned on all sides (including the pin that was standing proud of the inside surface and rubbing on the frame), as well as having the sharp edges and corners broken with the stone. Mr. Kuhnhausen doesn't say "make it round", he just says to break the edge so that's what I did. The only other work done to the rebound slide was a few quick strokes with a round needle file to clear any burrs from the spring channel.
Quite a bit less effort than was put into the rebound slide in Short & Sweet.

The bolt was removed (with no Zing! this time) and the inner cheese-grater surface was stoned smooth along with breaking the sharp edges all around.

 

[Shotguncoach]

The trigger had been waiting patiently this whole time and was happy to finally get to tell its' story.

"Are my surfaces supposed to look like a lasagna noodle?" was how the trigger opened the conversation. I thought it was kidding until I looked at the bevel surface. Wavy and with inconsistent contact. A little quality time with a stone made the bevel much happier.

The sear surface on the trigger wasn't in much better shape, which meant that I would finally get to use my fancy trigger stoning jig. Get everything out of the box, find the adapter, put on the adapter, read the instructions, mount the trigger, set the height to 20 clicks, look with a magnifying glass at the relationship of the stone to the sear.....and then 5 strokes with the stone. What a let down. There's a joke in there somewhere but this is a family forum and we won't go there.

The last work on the trigger was to clean up the lasagna noodle surface on the front where it interfaces with the cylinder stop. I went a bit farther here and made it a bit more rounded because I like a smooth trigger return.

 

[Shotguncoach]

There really wasn't a whole lot more to do before it went back together....

The hand appeared to be rubbing slightly on the right side of the window so it made a few passes on the stone before being installed onto the trigger. Another new thing I learned tonight was to use a punch that is the same width as the spring channel in the trigger to move the hand spring into position to reinstall the hand. I had been using a dental pick with mixed success as the spring kept slipping off the pick. The right sized punch gave the spring no where to go except the right place and the hand just slipped in.

The hammer block had a bevel put on both top edges with a smooth cut file and then a full rub down with 600 grit sandpaper. The small end of a round ceramic stone was used for a quick high-spot polish in the sideplate where the hammer block lives.

Right about this time the dogs decided that they needed to go outside, and I took the opportunity to have a conversation with myself about what springs to put into the gun while the dogs did their business. I said to myself, "Self, this would be a good time to find out what all this straightening, stoning, and polishing really does. Is it really worth the effort or do all the gains just come from swapping springs? Let's put all the original springs back in and find out."

It seemed like a good idea so that's what I did.

The result? A crisp, clean 3 lb single action break and a smooth, even 9 lb double action pull with a full 72 ounces of hammer tension. Remember where we started in the first post:

The initial trigger pull tests showed 4 1/2 lbs single action and 10 1/4 lbs double action. The single action break had a fair amount of creep and the double action pull was peaky and uneven. Backing the strain screw out 1/2 turn dropped the numbers a bit to 3 3/8 lbs single action and 8 1/2 lbs double action. The peaky double action pull seemed to get worse with the screw backed out.

The full tension ending weights are very close (better for the single action pull) to what we got with the strain screw backed out.

Lots to think about here. I got the results I was hoping for without having to touch the springs or the strain screw at all. For now the strain screw is all the way in and we're going to go shooting.

To button everything up I installed a set of football diamond target stocks that I got on fleabay for a cheap price because there is a chip missing from the top right side. I know they're not original and they're kind of beat up, but the diamond targets fit my hand so much better than the later non-diamond stocks that I don't care. Pretty is as pretty does.

Total time on this one was just over 2 1/2 hours.

 

[Protocall_Design]

For dry firing any S&W revolver, you can get a 5/16 or 8mm OD rubber O ring and put it in the frame around where the firing pin goes. The hammer then hits on the O ring, saving the wear on the firing pin & spring, and cylinder in the case of rimfires. One O ring fits all calibers, no need for several different sets of snap caps. The O ring is easily removed with a toothpick or similar shape tool.

Don't forget to smooth out the 2 long sides of the triangle hole in the bottom of the hammer block.

 

[armorer951]

Great photos. Thanks for your illustrations and for sharing your work and results. We can learn a lot, which is what this sub-forum is all about.

Not to be critical of your procedures, but I did read something that made the hair stand up in the back of my neck....

"To get it to line up, I removed the gauge pin, closed the yoke, put a hammer handle vertically on the "push from this direction" mark I had made on the yoke barrel, and leaned my upper body weight onto it."

Actually, the yoke liner tool should stay inside the yoke barrel for support while you are making adjustments to correct misalignment between the yoke and the center pin cavity.
Also, S&W recommends exerting pressure on the yoke barrel using a wooden wedge. This technique spreads the pressure out over the surface of the yoke tube and helps prevent damage.


On a diagnostic note.....the back of the sideplate can provide some interesting information regarding some potential problems with the internals.




Carter

 

[Shotguncoach]

Thank you Armorer951….that’s exactly the kind of advice I need. I’d like to dig deeper into the wedge if you don’t mind. I can see how pushing the wedge into the frame window either above or below the yoke barrel would produce vertical movement, but I’m having trouble visualizing how to produce horizontal movement with the wedge…

 

[armorer951]

You're correct about using the wedge (hardwood) in the frame window under the top strap and above the yoke barrel (to push down) and between the frame and the bottom of the yoke barrel for an "up" adjustment. Just tap the end of the wedge with a small hammer to exert the needed force. (after inserting the liner for support)

Make sure the yoke is fully "closed" during these up and down adjustments.

The side to side adjustments are one of those "need a third hand" challenges.

For side to side adjustment, I've always used a wide plastic or rawhide hammer to strike the yoke barrel, with the liner inside to support the tube. You could use almost any "non-marring" material that had a wide enough face to better distribute the impact of the tool.

Make sure the yoke liner doesn't slide back into the interior of the yoke and expose the end of the yoke tube (leave it unsupported) during these adjustments.

After positioning the frame on the bench with the top strap in the "up" position, tap "down" on the yoke barrel with the yoke fully inserted, liner installed and yoke in the open position. This will move the end of the yoke barrel incrementally toward the thumbpiece, or "frame" side.

While holding the frame in your palm, or after laying down on a padded bench, tapping from the left side through the frame window, with the yoke closed, and liner installed will move the end of the yoke barrel incrementally toward the sideplate side of the frame. It usually doesn't take much force to move in small increments.


The wedges the factory distributed to me are oak......any hardwood would work.






Carter

 

[smitholdtimer]

Shotguncoach

Please understand that I'm just asking but in your photos of the revolver internals it appears to me that the hammer & trigger are blued and as you are, I'm sure, aware, this isn't normal. Am I not seeing things clearly or are they actually re-blued?

I really appreciate your detailed photo description of your internal improvements, thanks for taking the time to show your progress.

 

[viceunit]

Please understand that I'm just asking but in your photos of the revolver internals it appears to me that the hammer & trigger are blued and as you are, I'm sure, aware, this isn't normal. Am I not seeing things clearly or are they actually re-blued?

I really appreciate your detailed photo description of your internal improvements, thanks for taking the time to show your progress.

In post #2 it is pretty clear the hammer and trigger are case hardened.

 

[Shotguncoach]

Now stored with the fixture and the alignment gauges......


I want to give a shoutout to armorer951, Protocall Design, steelslaver, 2152hq, handejector, Pig Hunter, and all the others who have commented with advice in these threads. I appreciate the time you've spent sharing your knowledge and helping me learn. You are what make this a great little corner of the internet.

 

[Shotguncoach]

Please understand that I'm just asking but in your photos of the revolver internals it appears to me that the hammer & trigger are blued and as you are, I'm sure, aware, this isn't normal. Am I not seeing things clearly or are they actually re-blued?

I think what you're seeing is a feature of how the light from my fluorescent bench light reflects off the steel. I was trying to turn the hammer to highlight scratches and ended up with that visual effect. Both are case hardened...check posts 2 and 8 for better pictures.

 

[smitholdtimer]

viceunit

Look closely at the third set of photos from top, these are the reason I thought they were blued, the ones that are removed from the revolver. I agree the internals that are pictured that remain in the revolver with the side plate removed certainly appear to be case hardened.