Now that I have the frame, I can really get going on this build. It’s time to work the slide-to-frame fit. The Caspian slide came out as a good match for the JEM frame. The frame’s slide rail was just a bit oversized and allowed material for narrowing it to fit.

As the first step, I “mapped” the slide and frame. That is, I measured all the critical dimensions and recorded them on a convenient summary sheet from 1911 Builders. I will tell you that I found it hard to get good, repeated measurements using my digital calipers! The pros use a micrometer and I need to get one.

Fortunately I did not need the dimensions for milling the parts to fit, I needed them to give me an idea of where I was going and a checkpoint along the way. The real test for proper fit and the next place to sand/stone was the ink-and-fit approach.

The slide turned out to be just a shade tall which required me to sand off the bottom. I did that sanding with 220 grit and 320 grit wet/dry sandpaper and a little cutting oil. Using a surface plate gave me a known flat to put the sandpaper on and sand against. Ink, fit, sand, repeat. Soon the width of the frame rails needed work.

Narrowing the frame rails turned out to be most of the tedious work. Stone a little, ink, fit, stone some more, and repeat. A lot. I didn’t want to go too far and end up with a loose side-to-side fit.

Key to getting the frame rails narrowed, but still flat and vertical, was the Everglades Ammo Stoning Tool. Version 2 of the tool is recommended as easier to use. The 320 grit stone that it came with worked well.

When I had inked and sanded/stoned for a while, the slide started to go on the frame. Then it went on a little easier and a little further. Finally it slid on smoothly and would move back and forth just by tipping the frame up and down – just right! The important thing was to ink and fit frequently and sand/stone what the marks indicated.

I did not use any lapping compound at all. There were some recommendations to lap the slide in the last little bit with some non-imbedding lapping compound. Others advised against it saying you can never really get all the compound out and it will continue lapping until your slide-to-frame fit is ruined. I’ll have to see if this was a good or bad choice in time.

I was pretty concerned about this part of the build because I wanted a very nicely fit slide. It didn’t have to be high-end-custom-perfect, but I wanted it respectable. I think I got that.

If you’ve started partway into this series, you can find the beginning here. Or you can continue with Part 6.