Jim Garthwaite’s 1911 Class

Last week, I spent some vacation time and enjoyed a week in Watsontown, PA. Several months ago, I scheduled a class with Jim Garthwaite to learn how to build a 1911. The class was fantastic. I learned a few important steps and processes:WP_20150807_13_53_05_Pro

  • Tear down and evaluation
  • Fitting the frame and slide
  • Fitting a barrel
  • Fitting a barrel bushing
  • Fitting a grip safety
  • Fitting a thumb safety
  • Fitting the trigger components
  • Misc
  • Test firing
  • Checkering

Tear down and evaluation – I have broken down a 1911 many times over the years, and I have always used a different method than the one that Jim taught us. I have always removed the recoil spring plug, then the slide stop. Jim’s method is to remove the slide stop first, and to hold the slide so that the recoil spring is captured in the hand. This process has a few nice benefits, one is the ease of inspecting how the guide rod engages the barrel link lug, and another benefit is that the barrel can be removed along with the barrel bushing by moving the barrel bushing further down the barrel and away from where the barrel is thickest. This method takes away the stress on the barrel bushing during disassembly. Jim then showed how he goes through each part and looks at wear marksWP_20150807_13_00_53_Pro and looks for any machine marks that need to be cleaned up as well as any edges that need to be cleaned up because the original cuts were not completed.

Jim showed us how to properly identify metal injection molding (MIM) parts. The important concern with MIM parts is that they are OK to use for some components and should never be used for others. The hammer and hammer strut, to the right, are perfect examples. The circles on the hammer strut identify it as a MIM part. The hammer, itself, is tool steel. The hammer has significant stress put on it each time the gun is fired. The spots where it engages the sear must hold their shape and not wear easily. The hammer strut, doesn’t experience significant pressure on it, so it is not an issue if it is a MIM part.

Frame and Slide – While we didn’t actually do the work on our individual builds, Jim took some time to show us the process on another build that he was working on. We got to see the process of tightening up the frame and slide fit from the measuring, to the peening, and the lapping process. We didn’t do the work in our builds because very little accuracy improvements can be made with this work. The vast majority of accuracy improvements come from the barrel fit and the barrel bushing fit. Of course, it was also a non-issue as the Springfield Frame and Slide fit incredibly well from the start.

Tools used included the following:

  • Vice
  • Peening hammer
  • 1911 Auto Slide Rail Micrometer
  • Everglades Slide Measuring Tool
  • Verniers Calipers
  • 1911 Auto Slide Fitting Bars
  • Files
  • Sandpaper (80-220 grit for most of the work})
  • Lapping Compound – Aluminum Oxide 600-800 grit

Fitting the barrel – We started with a Kart match grade barrel with oversized barrel WP_20150807_13_03_52_Prohood. Using a hood length gauge, we were able to measure the length from the breech face to the first lug in the slide. Next, we measured the length of the barrel hood from its edge to the first lug. The difference is what we had to remove from the barrel hood. For the left and right of the barrel hood, we were able to find the amounts to remove by measuring the width of the opening for the breach face, which gets us the total amount to be removed. To find how much needed to be removed from the right and left side, we measured the port side width of the slide and the distance to the barrel from the port side. From these measurements, the amount of material to be removed was found for the left and the right (port) sides of the hood.

Once the length and the sides of the barrel hood were filed down so that everything “almost” fit, then the rest of was lapped in. It was clear where the lapping fluid cut away material as it had a very nice shine to it. BTW, the barrel to the right is a bit dirty as I took the pictures after test firing.

To complete the barrel fitting, the lugs needed to be cut to fit the slide stop, and then the WP_20150807_13_03_24_Prolink needed to be pinned into place. As with everything we cut/filed, we cut the material down so that it was “almost” complete, and then lapped in the last bit to make sure we had a nice and tight fit, but that it didn’t bind.

The red in the picture to the right might be Dykem or it might be my blood. Smile

Tools used included the following:

  • Vice WP_20150818_20_41_48_Pro
  • Hood length gauge
  • Verniers Calipers
  • Depth micrometer
  • Plastic/Brass Hammer
  • 1911 Auto Lug Cutter
  • Files
  • Sandpaper (80-220 grit for most of the work)
  • Lapping Compound – Aluminum Oxide 600-800 grit

Fitting a barrel bushing – The key to fitting the barrel bushing is to make sure it has WP_20150807_13_05_39_Proenough room to tilt as the barrel goes into and out of battery, but not so much as to introduce slop and take away from the gun’s accuracy. In our cases, the barrel bushing didn’t take any work. It was a nice and snug fit, but still allowed the barrel to tilt. In my case, though, we had to take a little off of the front of the slide.

The barrel bushing is snug enough that it won’t just turn by hand and be removable WP_20150807_13_18_16_Prowith the bushing wrench. It will turn with the bushing wrench, but the barrel is actually used to bring it free by sliding the barrel forward after the bushing is turned properly so it can be removed.

Tools used included the following:

  • Vice
  • Verniers Calipers
  • Depth micrometer
  • Sandpaper (80-220 grit for most of the work)

Fitting a grip safety – The grip safety was, by far, the most fun that I had in the process of hand fitting the different components used in this build. In our cases, we used a nice beavertail grip safety. The work involved a few steps.WP_20150807_12_56_57_Pro

  • Fit the safety to the tang which, once fit, allows the safety pin to slide through the frame without interference. The tang should be fit so that the grip safety moves smoothly over the tang and is still a very close fit. Without a doubt, this was the toughest part. Fitting the tang so that its radius matches the grip safety’s radius meant that I had to apply lots of dykem, file, test it, mark it with more dykem, file, test it, and so on. I must have had the grip safety in and out at least 30 times to get this to match up nicely. WP_20150807_13_02_21_Pro
  • Fit the safety to engage the trigger bow. The whole purpose of the grip safety is that it has a leg on it that prevents the trigger bow from moving back and allowing the trigger to engage and fire the gun. In my case, it took some filing to get it to fit properly and disengage so that the trigger bow could move back.
  • Fit the external part of the grip safety to fit closely to the outside of the frame. This was WP_20150807_13_17_50_Prothe fun part for me. It was a joy to “sculpt” the external part of the grip safety to closely match the frame.

Tools used included the following:

  • Vice
  • Files
  • Sandpaper (80-220 grit for most of the work)

Fitting a Thumb Safety – The thumb safety is another part that needs to fit properly. WP_20150807_12_59_29_ProIt must be snug up against the frame so dirt and grit can’t get in between very easily, and it needs to be be smooth, but also it needs to have a very positive engagement and disengagement. After all, when it is engaged, we want it to stay engaged until we want to disengage it. The thumb safety, in my case, took a little filing so that it would full disengage and allow the trigger bow to move forward. WP_20150807_12_58_56_Pro

Another key to the thumb safety is that it needs to be shaped and contoured so that it is comfortable when against the body and is comfortable when being engaged and disengaged.

Tools used included the following:

  • Vice
  • Files
  • Sandpaper (80-220 grit for most of the work)

Fitting the Trigger – This involves more than just just fitting the trigger and the trigger WP_20150807_12_58_33_Probow. Filing the trigger’s top and bottom to fit the trigger channel is important. The trigger needs to slide in and out of the channel without dragging, but it also should move without having slop. An adjustable trigger can also be used to minimize/remove the over travel in the trigger.

As far as the well discussed “trigger Job” that is a part of all professional upgrades, there are lots of great jigs out there to help make sure that the sear engagement and the hammer engagements points properly fit and are as smooth as possible while locking up properly. Starting with good tools steal components is vital. We want those parts to keep their edges and points of engagement without wearing or deforming. WP_20150807_13_01_31_Pro

Another point of consideration is the disconnector. Its engagement with the slide is vital, but it is fairly easy to clean up the engagement points and polish them. Of course, the flat part of the disconnector that contacts the trigger box must also be properly polished so that it doesn’t drag when the trigger is pulled.

Tools used included the following:

  • Vice
  • Trigger jig
  • Files
  • Sandpaper (80-220 grit for most of the work)

Misc – The gun will need some clean-up. Basically, if you think about all of the edges and burrs that you can get in the manufacturing of metal objects, it is easy to see how the little things need to be cleaned-up. All parts should be full deburred, all edges should be rounded and cleaned so that they are smooth. WP_20150807_12_57_23_Pro

I heard the perfect description from Jim. He said that we should think about guns as something we wear, not something that we carry. They must be comfortable, and the only way we will have them comfortable is to round all of the edges, but we also need to be careful as to not make the edges and corners so soft that it is like a bar of soap. The image to the right shows how some of the edges have been rounded, but they are not overly dramatic.

I really liked Jim’s modification of the grip screw bushings, too. Taking a little off of the grip screw bushings is a great idea as it prevents the grip screws from directly locking down onto the bushings and prevents the bushings from backing out of the frame when taking the grips off. You can see in the picture to the right that the bushings have been filed down.

Tools used included the following:

  • Vice
  • Buffing/Grinding wheel
  • Files
  • Sandpaper (80-220 grit for most of the work)

Test Firing – Well that is a big duh. Of course you need to test fire the gun, but it is important to note any issues during firing. Wheter the extractor catches too much of the case and causes deep scratches, for example.

I was never told about clocking rounds so that they could be better used to identify any problems with the firing process, until I was in this class. As I was firing Remington rounds, I put the R at the very top of the round when loading my magazines. I could then look at the spent casings and see if the extractor was digging into the case, I was also able to look at the ejector impression, and verify that the firing pin was hitting the primer properly and was nicely centered.

Clocking would have shown whether the firing pin was too high or low because of issues with the barrel fit and the barrel not fully moving up into the barrel lugs in the slide properly.

Checkering – I am not comfortable with checkering, just yet, so I didn’t do any checkering on this particular gun. I do plan on spending some time working on some scrap metal and practicing for a future build, but I am not there just yet.

Summary

I strongly recommend attending the class if you have the opportunity. It was worth more than I ever thought it would be when I signed up.

FINISHED

WP_20150818_17_17_03_Pro

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