I have a slide (no name) that is really heavy, seems well built, the depth of the locking lugs is only about 40 thousandths, is that satisfactory? I was told by a reputable gunsmith that it was as long as I have full lockup. Is there a way to deepen these on the slide?
The average (mid-spec) Gov't Model slide will have a #1 lug whose face is about 0.061" deep, the others being about 0.005" and 0.010" less deep.
0.040" is considered by many to be the bare minimum amount of vertical engagement at the #1 lug.
Is there any way to deepen the slide for more lockup?
I suppose they could be cut deeper by a machinist using whatever cutter and type of machine is used at the slide factories. The specs for the cutter (or the lugs, really) are in the blueprints in our Tech Issues section.
Perhaps they could be scraped deeper by hand with a properly sized scraper made from a lathe bit, but that's a lot of scraping to do and I'm not sure how well it would come out.
Maybe somebody else knows for sure. Never done it either way, myself.
P.S.: Have you considered the possiblity that the lugs may only be 0.040" deep because the central bore of the slide was too high up in the slide - or at an angle?
I think that Brownells has a tool to do that. Call Brownells and ask them.
According to the sticky from Brownell's Mike Watkins, http://www.brownells.com/aspx/NS/Gu...x?p=0&t=1&i=530 he prefers .045 total lockup and says .040 to .045 is OK. If your slide is only .040 deep you would have to achieve a literally perfect fitup to even get to .040. It sounds like a little deeper cut would make life easier in getting proper lockup depth.
I know that my slide is only 40 thousandths deep, when I measue the lock up I get about 45 thousandths, doesnt make any sense.
Technically impossible, No? I use a depth guage mic on the top of the slide to the top of the hood with the barrel out of battery, then the same with in battery. Difference equals lockup. I'll bet your getting a goofy reading on your slide measurement. Just a guess. Perhaps the slide is a Sarco type affair that was bought from factory rejects etc. where everything is not up to spec.
Very well could be a reject, I measured it again several times and I must have been doing something wrong becuase now I am getting an average of about 40 thousandths.
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I use a depth guage mic on the top of the slide to the top of the hood with
the barrel out of battery, then the same with in battery. Difference equals
lockup.
If your "to the top of the hood" measurement is really taken at the aft end of the barrel where the hood is, your engagement calculation will be increased by change in barrel angle between battery and the disengagement point.
These depth measurements should be taken at the very front of the ejection port to avoid almost all of that error.
But, maybe I misunderstood what you wrote.
You're absolutely correct and that is what I do. Should have said top of barrel, not hood.
Bought a new Colt slide a few weeks ago. When examining it I noticed the lug slots looked kinda shallow. Pulled out another bone stock late model factory Colt and checked it too. The rear lug slots are just a gnat hair more than .040 on both slides. That is using the long end of a dial calipers so they are probably a hair deeper due to the square nature of the measuring device going up against a radius. But not much.
Measured a 60's vintage hard slide at .065 just now.
Measured Chip McCormick (made by Kimber) slide at .073 just now.
Measured a 1918 Black Army 1911 slide at .083 just now.
Now I am wondering if Colt decided to reduce this depth or they are still suffering QC issues.
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Bought a new Colt slide a few weeks ago. The rear lug slots are just a gnat
hair more than .040 on both slides.
I suppose the next step is to get rid of lug #3. There's probably some bean- counter working on that idea at this very moment!
Well, this has got to bugging me bad enough I wrote a snail mail letter to Colt. When I get some information I'll post it right here and clear this issue up.
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...I wrote a snail mail letter to Colt.
Good decision. I'd like to think it would get more (perhaps lots more) attention than an email. Colt probably gets hundreds of emails a day about various things.