Lapping compound vs files and stones

[repins1911]

I have built a few 1911s and used both methods when fitting the slide to frame. Looking for the input of some the smiths that have have used both and what your preference is and why. I know some guys will only use files and stones but wanted to see what the general consensus was for my own edification; and for some tinkerers that may want to do a full build. Thanks in advance!

[mike cyrwus]

removing material is removing material. Files go faster, way faster. measure often. neither method can match the speed and precision of a good vertical mill. I save my stones for trigger parts

[zzt]

I do not lap, because you cannot control where the compound goes and you end up removing metal in more places than where you wanted to. I use big files for removing a lot of material from the bottom of the slide. For everything else I use large and small diamond hones, stones and a good surface plate with sandpaper down to 8000 grit.

[BrianATL]

Mill and maybe some extra fine sand paper on a block to polish, don't like the lapping compound for reasons stated above.

[WhiteDingo]

If I'm sure of the square-ness of the slide rails I will cut exactly to fit on the mill (carbide, high rpm). If not, I will cut close and then hand fit. I'm not a huge fan of lapping a frame to slide fit, but it can get the job done.

[asr1]

Many years ago like back in 1999 I purchase Para P16 limited and when I tryed to shoot it the slides would not run as it suppose to and i have to run the slide by hand every round it was paper wight I was very upset because high $ pistol that don't work.

I called Para and they told me I need to keep shooting and eventually will break in so I called a friend of mine who worked in undisclosed RD aviation lab in developing things he don't talk much about,he give me a lapping compund in 2 very small syringes one is Red and the other is Blue in color I put some of the red first as he advised me on the frame and the slide rails I cycled them by hand 10 times then i cleaned both and they felt better repeat with the red agin but this time cycle 5 times only the fit was jus perfect no play and it runs smoth so I used the blue and 10 cycle of the slide cleaned and test the slide to frame fit was like gliding on roller bearing.

That gun never jammed again and I shot with it about 10000 round before I sold it and the fit is perfect no sign of wear or any play

So I believe in lapping for final fit

I think the The Red and Blue compound can be found at MSC but I am not sure if it is the same grade and qulity stuff like he brought to me

[bubbadoc]

I always have thought that it is files to really remove metal. Stones to remove a little but more polishing smoothing. Lapping compound can be used to get the final burrs off, especially in areas you have issues reaching evenly (so you can apply and rub the parts across each other).

I also will use lapping compound on a rag and use on small parts to get rid of small imperfections and generally smooth.

[Jediwarrior]

I mill cut the slide if it is oversize by 0.002 in. I leave 0.0005 in. so I can use a sanding block to remove the tool marks.

Same with the frame, I mill the sides of the rails and leave 0.0005 in.

I use the Brownells slide rail micrometer and a regular outside micrometer.

I have never used lapping compound.

Edited February 17, 2015 by Jediwarrior