glw

I need to make some shims for the hammer on my GP-100, but I would like to know the best way to do this. (I have Iowegan's IBOK, but it doesn't say how to make the shims.) I have some shim stock in various thickness, but how do I cut it without twisting and distorting the metal?

Thanks!
Glenn

bowhunter

glw, This is the "best" way I have found to make the shims your talking about. I clamp the piece of shim material on a small piece of wood clamped with two small machinist clamps, one on each side of the stretched shim material and mount that fixture in my drill press vice. I do this in order to "drill" the size hole I'm going to need for the hammer/trigger cross pin. Once the hole is drilled, I place the drilled shim material on a piece of hardwood and "punch" the appropriate size I need with a metal Hollow Punch Set. My set has punches from 1/8" to 3/4". This gives you a nice symetrical shim already drilled and ready for use! You can get a Hollow Punch Set from Harbor Freight or your local Industrial Supply...........................Dick

glw

Thank, Dick. I have a Harbor Freight near me. I just called them, and the punch set is only $5. That sounds like an easy way to make them. I'll stop by to pick up a set in the next couple of days.

If there are other ways to make them, I'm all ears. It's nice to know different ways to do the same thing.

Glenn

45 Colt

Transfer punches can help too.

Rover

I recall at one time Teddy Jacobson talked about some types of adhesives used in gunsmithing. I was wondering if there is a way to use an adhesive that would attach the shims to the hammer to ease reassembly? Has anyone tried anything that works without gumming up the interior of the gun?

Iowegan

Rover, To minimize friction, you want the shim to move so I don't think an adhesive would work well. A dab of oil makes the shim stick to the hammer so installation is easier. I use a tooth pick to help center the shim, once the hammer is in about the right position. A bit tricky but well worth doing if your hammer is rubbing on the frame or your trigger pull is not uniform.

Rover

Thanks for the info, Iowegan. Reducing the friction makes sense. Must not have had my morning coffee as was thinking about bosses on S&Ws. Still, wondered how you
kept them in place.

Iowegan

Rover, Your post jogged my memory ... the best way to keep the shims in position is to use a "follower". To make a follower, cut a .316" length from a 3/16" drill bit shank. Grease the follower and slide it into the hammer hole. Put a shim on each side then lower the hammer in position. Use the normal hammer pivot and push it into position from the right side. This will push the follower out of the left side and leave the shims exactly where they belong.

I made a follower several years ago and used it a few times. It has since been sitting in my tool kit, totally forgotten until now. I have other "mystery" tools in there too.

glw

I bought some hollow punches at Harbor Freight and made some hammer shims. The directions I received on the forum were great, but the punches were not so great. I couldn't use hardwood when I cut the shims, since when I used oak it only made dented metal but wouldn't cut through it. I finally was able to cut the shim when I used the anvil on my vise but the cut wasn't very clean. I still needed to use a file to trim off the edges. The shims were not flat, but were warped toward the center. I guess they might work, but were not what I was hoping for.

Does anyone know of some good punches that won't cost a fortune? I won't be making many shims--only a few for my GP-100 and a couple of other revolvers.

Thanks for you help. This forum has been a great source of information.

Glenn

bowhunter

glw, Sorry the Harbor Freight punches were less than useable. I got mine fom a local tool shop but are essentially the same as Harbor Freight's. Mine happened to be very symetrical and not warped. They do need to be sharpened to work well. Chuck them up in a drill press or lathe and rotate against a "good" fine India stone followed be a "hard" Arkansas stone. I had some individual sizes a long time ago made originally by Starrett but am not sure if Starrett is still making them. Everything Starrett or Brown & Sharpe makes, in my opinion, is top quality..............................Dick

glw

Hi Dick,

Thanks for the info about sharpening the punches. Perhaps I can make them work yet if I sharpen them. I didn't think about chucking them in a lathe (I have a wood lathe) to sharpen them. I'll give that a try and see if they work better.

Glenn

Bob Marly

What is the diameter of the pivot pin? Is it 3/16" as noted with your follower pin Iowegan?

I am offshore right now so I like to make up some little bits and bobs for when I get home to tinker.

bob marly

Iowegan

Bob Marly, Yes, the hammer pivot pin is 3/16". The hole in the shim needs to allow free movement for the pivot pin.

Jonah

That's what I like about the internet forums. You find ideas from others on simple ways to do different things. We never get too old to learn new techniques. A lot of the time, it's a "why didn't i think about that?" type of an idea.

Keep the ideas coming.

xr650rRider

I made some shims for a Ruger 77/22 bolt. I put 3 different thicknesses between 2 pieces of 1/8" strap clamped together. I then drilled several 29/64" holes in all of the pieces. Used scissors and cut out small squares of the shim stock with hole drilled in it. Used a 7/16" bolt and placed washer followed by all the cutout square shims on top of it, followed by another washer and nut. Tightened the assembly up and then placed the bolt in a drill. Using bench grinder, rotated the assembly against the stone until I got the OD I wanted. I will have to lap the shims to remove the rough edges but I have several shims of each thickness to do what I want.

fjlee

You'll have FAR better luck punching out shims if you orient your block of wood so that you are punching INTO the end grain of the wood.

To clarify.......lets say that you are using a 8" long hunk of 4x4 wood. Stand the hunk up.....so the 8" dimension is standing vertically. You'll be looking down on a 4"x4" work area. The 4x4 end grain will be your "work surface". Cutting shims, gaskets, etc is always easier that way. The punch will penetrate in a much cleaner manner.

FjLee in Denver CO

Armen

I just buy mine from Power Custom or Brownells.

Fritz

Slotracers have all kind of spacers and axis for their slotcars. Serve well for guns.
Fritz

Drew458

I don't know if these are the best ideas, but I tried both when making shims for my SP101 hammer.

I've got 2 of these little pistols, both new, and the total gap seems to be running about .021-0.022". So that looks like .010" per side. I think it's best to measure at the hammer pin hole, not up at the top of the slot.

It turns out that roofing flashing is 0.093" thick. It's aluminum, but I think it's sprayed with plastic or something as it never oxidizes. And aluminum is much softer than stainless steel, especially the hardened feeler gauges. So the flashing was very easy to punch and to drill, and the cut edges clean up in seconds on a whetstone. You can buy a whole roll for $5 at Home Depot, enough for a zillion shims.

I also found that the feeler gauges from K-D Tools (the typical gauge company found in a NAPA autoparts store) have a nice smooth hole in one end that's just a little big for the SP101 hammer pin. All I had to do was snip off that end of the gauge and then clean the edge on a whetstone. The shims don't have to be round. "sorta round" is good enough. Maybe a perfect fit shim that's perfectly round will work better, but it will be hard to tell the difference. They're just spacers after all.

Both methods are in place now on my SP101s and are working just fine. Hammer shims make a huge improvement in smoothing out the trigger pull. Amazing.

thebiggiantkevin

Thanks for the info Drew458. The side of my hammer is scratched. I may have to give it a try on my SP-101.

I have to wonder... if Ruger can make 1 zillion shims for $5, and they seem very easy to install - why don't they put um on at the dang factory???

METerry

I wimped out on shim class and bought Power Custom shims from Brownell's. I didn't even try to make them.

It's an expensive alternative but an alternative.

acutedeath

Are you referring to the 713-000-063 and 713-000-064 sets on Brownells? (Power Custom "Ruger Hammer and Trigger Shims) These are listed for SA revolvers, Although I fail to see why that would matter. Those are definitely not cheap. I might buy some anyway though, as I do not have the tools required to make such things in this tiny apartment.

acutedeath

Edit: Removed fairly stupid comment.

I guess I really want to know if the hammer set fit the GP-100 (ie, OD .5" ID .2" according to the IBOK). I don't want to just assume this is the set that others are referring to and waste a perfectly good $18.

Drew458

METerry, the shims you make yourself are a perfect fit for your pistol. The Power Custom shims at Brownells? They don't tell you the outside diameter, the inside diameter, and one doesn't even say how thick they are. The other one is 0.002" thick. I would have had to use the entire 10 pack of them on my hammer to fill the gap, assuming they had Ok diameters. And it was tough enough lining up the hammer and just 2 shims!!

Sacrifice 2 K-D stainless steel feeler gauges. Use the hole they made. It's super easy that way, a 3 minute job total with no other investment. You can cut steel that thin with scissors if you have to. Sure, one side will be 0.001" thicker. Who cares? You can always try it thicker on one side first, then the other side, to see which gives you a better trigger. And you can get the clearance down to .001" total, just half a thou per side. You just can't do that with random shims you buy.

dntama

You can also check out McMaster-Carr. The shims they had worked for me.

acutedeath

I like the McMaster-Carr website for the progressive filtering of their products. Thanks for the suggestion.

Drew458

dntama - which model and what size & thickness did you use from them?

Drew458

IBOK spec for trigger shims: .3" OD, .1" ID
5/16" = 0.3125"
#38 drill bit = 0.1015"


IBOK spec for hammer shims: .5" OD, .2" ID
1/2" = 0.5"
#7 drill bit = 0.2010"


I did the trigger shims for my SP101. The gap measured 0.008", so allowing for 0.001" clearance on each side, I drilled out the holes then punched two shims out of a K-D Tools stainless steel 0.003" feeler gauge. I used the 5/16" punch, which is .3125". Close enough. I found that a white nylon cutting board from the kitchen makes a great surface to punch against. Yeah, when the punch cuts through it will leave a little round cut in the board, but your wife will never notice.

Feeler gauges are very hardened steel. They are almost brittle. The first time I tried drilling the hole I used a #38 drill bit (0.1015") and the bit tore the steel gauge. I found it was best to drill the hole in stages, starting by using a sharp nail to make a slight dent, then drilling the hole using a very small drill bit, then redrilling it several times with successively larger bits. Drill it through from both sides to get rid of any burrs. The #38 drill bit was the 5th step, and I got a perfect smooth hole.

I put the trigger assembly back together and everything worked fine. I assembled the gun and dry fired and things were very smooth. But the action seemed somehow "slow". I took it all apart again and learned something new: the right side trigger shim was too large. When the action cycles, the cylinder latch moves up and down. In it's down position it almost touches the right side trigger pin boss. With the .3125" shim in there, the inside edge of the latch was dragging on the outside of the shim. The right side trigger shim has to be much smaller, perhaps only .2" diameter, so that it never extends past the forward edge of the trigger pin boss. It was easy to trim down to size using a pair of those Wonder Shears ("so strong they can cut a penny in half!"), and now the trigger is flawless. This is a very tiny weightless part, hardly bigger than a mouse's eye. Installing this one is one of those "do it inside a big Ziploc bag" situations.

The left side trigger shim diameter is fine at 5/16". It can even be a bit bigger. There's nothing on that side that it will interfere with.

*********

The other day I suggested using aluminum flashing for the hammer shims. I now withdraw that suggestion. The aluminum wears very fast. Use a K-D Tools stainless steel feeler gauge, and don't bother with a punch or a drill bit - the factory hole is just about perfect.

The K-D gauges are 1/2" wide and 3" long. They come in a set, all mounted to a little bolt mounted to a U-shaped bent metal handle. The hole they made for the bolt is perfectly smooth, and less than 0.02" larger than the hammer pin. Pefect.

I have 2 SP101s, both brand new. The hammers on these are way undersize; each rattles around in the hammer slot. Both pistols have a gap of about 0.022", which is huge.

Since K-D was nice enough to make their gauges with a perfectly sized hole, I figured it was best to try to measure the gap at the pin itself, by sliding the gauge in next to the hammer and then inserting the pin. This works fine, but what I then found out, by moving the hammer and the gauge back and forth, is that something is not parallel. I think it's the hammer slot in the frame. The hammer can rotate freely if the gauge is held to the rear, but it binds when the gauge is rotated to the front. Huh. I got around this by inserting the gauges from the bottom of the frame, angled forward looking like some crude trigger. There's plenty of room going in from underneath. This keeps the gauge out of the hammer slot so not binding occurs.

So I measured the gap as 0.022", divided that by 2 and took away a thou, just like the IBOK says, and determined that a 0.010" shim for each side was what I needed. The first time through I made out of aluminum flashing, and they wore quickly. The next time I used the feeler gauges, and I made them by drilling and punching and then removing any burrs with a sharpening stone. I put them in, and it was a rather tight fit for the 2nd shim, but the trigger pull was great. As I've said before, shimming the hammer is the greatest single improvement you can make, and it really was. But again, things felt a little slow. And I don't think the 2nd shim should have been a tight fit. It should have slid in easily. So I took things apart again ... and found out that my shims, cut from 0.010" feeler gauges, were now 0.012" thick. What the heck? They were burr free, I double checked. How did they somehow "grow fatter"?? I figured that out too. When you punch through metal, the punch tends to cup the washer you're punching out. The flat bit of metal is now slightly domed. I tried squeezing it flat with my calipers and I tried smacking it flat with a hammer. No dice.

So here's my workaround: go 0.001" thinner with one shim, and snip them out instead of punching. Use the factory hole in the feeler gauge. I did this, going 0.010" and 0.090". And don't forget to deburr the edges where you snipped. I made the cut ends "sorta round" but a straight cut would probably work just as good. I made my cuts to match the factory rounded end, so the hole winds up in the middle.

Here's a good test to judge the hammer/frame gap when you measure it. (Just because you can force a gauge in there doesn't mean that's the proper measurement!) With the gun taken apart, install just the hammer and it's pin. No gauges, no shims, no mainspring, no trigger assembly. Hold the gun muzzle down and pull the hammer back and let it go. See how easily it falls? The thing is a rattle. Now install your oiled gauge(s) from underneath and try this again. If things are too tight, the hammer will fall either slowly or not at all. As long as the hammer can fall faster than the time it takes you to say "one" you're Ok. Any longer than that and it's dragging. When I did my measuring, I did it first with just one gauge. When I found the right one, I installed it on one side, tested, then took it off and installed it on the other side and tested. Then I did the IBOK shim thickness math and installed those gauges, one on each side, and tested. Then I swapped them and tested again. Measure twice, cut once, right?

Once you make your hammer shims and install them, do the falling hammer test again. The shims will take away almost all the side to side wobble, but you don't want them to cause drag. If the hammer is falling slowly, take things apart and inspect the shims for burrs. If they seem Ok, cut a new shim from a 0.001" thinner gauge and try again. (this implies that you might need to purchase 2 sets of feeler gauges!) Yes, you measured carefully with the gauges and did the math properly, so what you made should be a pefect fit. But any cupping from the punches or burrs from the drilling or cutting will make the shims effectively thicker, and we're in the zone where a thousandth of an inch makes a big difference. For my SP101 to pass this test, I wound up using one 0.010" shim and one 0.009" shim, which gives me a total of 0.003" clearance.

My shimmed hammer falls freely and has no discernible lateral wobble. With the rest of the IBOK tuning the trigger is smooth as glass on both the pull and the release, and I'm getting consistent primer ignition with the 11lb Wolf mainspring. There is no interference at all on the cylinder latch. I am a happy camper.

Drew458

acutedeath

Thank you for the extremely detailed information. I'm sure that took a while to type, but I'm planning to shim my hammer soon and the advice is great.

shadohman

Great information and I just happen to have a couple sets sitting around the garage, can't wait to give this a try.

Shadohman

PeaShooter

Try these shims from Powercustom.com

PS-WT#2 S&W trigger shims I.D .107" O.D. .245 X .002 These should work for the Ruger trigger.

PC-RSA Hammer shims are I.D. .209" O.D. .421 X .004 These should work for the Hammer shims.

thisisdenny

^ good info, thanks for posting

Snobal

Thanks to all for sharing your experience.

I read this post yesterday morning and it sounded like a lot of fun to make some hammer shims out of the remainder of my old feeler gauge for my GP100.

I had cut up part of that old feeler gauge to make shims for the rear sight on a rifle several years ago.

My SP101 measured over .020" of hammer play, while my GP100 only had about .010". I figured the GP100 would be easier and should be first.

Drew458 --- Thanks for the tip on measuring from the "inside" with the trigger assembly removed! That saved a big problem for me because the "inside" measurement for the GP100 was about .023".

My first trial was installing the hammer between two feeler gauges to check that the hammer would fall freely, but with decreased lateral movement.

With the feeler gauges inserted through the trigger assembly hole (and using the "hole" end of the feeler gauges to actually mount the hammer) the total shim needed was about .021".....but.... that was more than would slide in from the top.....

Seems the inside of my GP100 frame is not uniform. The area around the hammer-pin hole was wider than where the hammer spur extends out of the frame.

Therefore, with the hammer in place, I could not install shims (that were thick enough to work) from the top --- so I very carefully removed some of the metal from the top of the frame "hammer hole."

I stopped removing metal when the hole was wide enough to get the hammer and and the first shim into the "wide" area of the frame, which allows the hammer to move over enough to slide in the second shim.

The gun looks no different with the slightly widened hammer hole, and the hammer shims work great!

Today I'll hit the pawn shops for another used feeler gauge or two --- and see how it goes making hammer shims for the SP101.

Thanks again!

Snobal

No luck finding feeler gauges at the local pawn shops today....the folks that worked in the pawn shops did not know what an automotive "feeler gauge" is....

Anyway, for $6.99 at a local auto parts store I found another feeler gauge for hammer shim "stock."

My SP101 was made in 1992 and has "almost" uniform interior dimensions --- so doing hammer shims for it took one hour and fifteen minutes this afternoon --- and came out great!

By the way, my SP101 took two .013" shims to get it right.

Thanks again for all the "tips and tricks!"

Snobal

Both the GP100 and SP101 test-fired fine with hammer shims a couple of days ago.

Loaded up a new batch of ammo with CCI primers yesterday and will re-test both guns again today --- just to make sure of their reliability with "hard" primers.

___________________

Update:

___________________

Only took the GP100 out to play today.

Had 3 FTF's out of 50 rounds using CCI primers. This was with the stock hammer spring. This was the first time I've ever had a FTF with a revolver.

Came home, cleaned gun, polished the inside of the frame some more and polished the shims a bit more. Before and after cleaning/polishing the parts today, the hammer falls freely.

Will try another 50 rounds with CCI primers tomorrow. If I get any more FTS's, I'll try it without the shims --- if that doesn't get it back to 100% reliability, I'll replace the hammer, hammer spring, and hammer pin.

Anyone got any other ideas??????

Snobal

The second trip to the range to test CCI primers with the new hammer shims was a little better.

I shot 50 rounds with Magtech primers in my cast target loads to get the gun dirty --- then fired 50 rounds with CCI primers. All 100 rounds fired.....

...But although all 50 rounds with CCI primers fired, 5 of the 50 primers had very minor primer "dents" --- just a tiny peck.

All the fired Magtech primers had deep, uniform dents.

As I shot and inspected primer dents, I noticed that all the dents in the CCI primers were deep and uniform when firing single-action.

Then I remembered and observed that the GP100's hammer falls a noticeably greater distance in single-action than double-action. I need the gun to be absolutely reliable in double-action for timed-fire and rapid-fire events.

While re-reading the GP100 IBOK last night, I found where Iowegan explained how to cure light primer hits when using light hammer springs. Although I'm using the stock hammer spring, it sounded like it would also be the cure for hard primers.

Iowegan --- Thanks again for the help!

I hope to get back to the range today to see if Iowegan's cure worked (or if I'll be ordering a new hammer and starting over.)

chaneyd

Clueless here. The purpose of shimming is?

b.hutchman

Reduce friction. On my Security Six, the trigger and hammer both have fine scratches on it from where they rub the frame. I made custom shims and put a drop of oil on them and it acts as a bearing and centers the trigger and hammer making them operate more smooth.

In the case of my hammer spring being reduced to 7lbs., the shims keep the hammer from dragging on the frame which robs speed/energy needed to set off the primer.

Hope that helps.

chaneyd

So, hammer shims if trigger and hammer have scratches? I'm not seeing any at all on my GP100's or SP101. Lucky?

fjlee

Harbor Freight has "32 piece feeler gauge set" for $2.99

SKU is 32214

I used feeler gauge stock to make hammer and trigger shims, and also to make a .003 inch shim to decrease endshake. This for my GP100. The endshake shim was the most difficult, because of the thin-ness. Hard to make a shim that thin, and have it turn out to be nice and flat..and not "waved" or warped. But it turned out real good.

FjLee Denver CO