View Full Version : slide fit too tight

Joe Portale
June 6, 2002, 10:22 PM
It seems that I have to be different. It seems everyone is asking about tightening the slide on 1911s. Now I have to go and ruin it. I picked up a brand new Colt 1911 slide that will re-emerge into the world as a 400 Corbon. Don't really have the time for a couple days, but couldn't resist popping it on the frame. The fit is really tight, I mean really , REALLY tight on the frame. This will be the first time that a slide spreader may be needed in the six 1911's that I have built. Okay, I know six ain't all that much, but what the heck...

Does anyone have a garage gun smith trick to open up the slide without resorting to another call to Brownells for the spreader tool? Thanks.

June 7, 2002, 12:56 AM
Have you thought about some lapping compound? It's available in different grits to allow you to tailor the fit as you desire.

Badger Arms
June 7, 2002, 02:23 AM
My first thought was also lapping compound. The main problem with lapping compound is that you can't have TOO tight a fit or it takes lots of muscle and effort to lap that first little bit. It also might take forever if there is lots of spring tension and the slide is, in fact, bending when you are putting it on. I really don't know how tight you are talking. I'd suggest either investing in the tool or tracking somebody down who will let you use theirs and perhaps give you a lesson in spreading it!

Unkel Gilbey
June 7, 2002, 02:59 PM
Take this one with a grain of salt.

A friend of mine had an auto that - too - was a bit tight. He took (of all things!) some Pearl drops - you know, the tooth paste(?), and ran a bead of it down both grooves in the slide. He would then sit in his easy chair and move the slide back in forth in the frame while he was watching his favorite program.

Before he started, he removed the barrel, and most of the other removable parts of the weapon, so it was basically the slide and the frame.

His treatment took about a week, but he wasn't really in a rush. After he thoroughly flushed out all of the paste, dried and lubed the pieces, and had reassembled the deal, it seemed to be a lot smoother than before.

Given the amount of abrasives, which is to say, hardness and size of the grains, this method really doesn't take a lot of metal off. On a really tight frame (as you are describing) it mightn't have any effect at all. But if you are trying to sneak up on a perfect fit, you might consider this method as an alternative.

Besides, it leaves your weaponry smelling minty fresh!

Unkel Gilbey

Jim Watson
June 7, 2002, 05:25 PM
Can you get it on the frame at all?

If so, my FLG handled one like that with oil and a rubber mallet. He just lubricated the rails and drove the slide back and forth until they burnished together. No abrasives at all.

JB Bore Paste is an effective lapping agent somewhere between valve grinding compound and toothpaste. It will cut surprisingly fast when confined between two pieces of steel, unlike its mild behavior on a cleaning patch; so don't overdo.

June 7, 2002, 08:26 PM
Gently lap.....and take your time.......and remember you can always take more off.........and when you're done you'll have a perfect tight fit.
BreakFree CLP.

(Remove all the stuff besides slide-n-frame.)

James K
June 7, 2002, 10:33 PM
Joe, I assume the frame is Colt or a good clone. Some of the other frames (Ballester-Molina, for example) will not work with a Colt slide.

I never heard of using Pearl Drops, but there are a number of fine abrasives that will work, including auto polishing compound, if you feel regular lapping compound might be too much.

Any way, there is no magic. I usually clamp the top of the slide in a leather padded vise and work the frame back and forth on it, using a rubber mallet in the first stages. Then, it is just back and forth, back and forth... well, you get the picture. I am sure someone has a machine to do it, but I never saw one.

I would not try to spread the slide. Fit the parts together by lapping.


Joe Portale
June 8, 2002, 11:15 AM
Hi folks,

The slide is a Colt and the frame is an Essex, for those who asked. I have built with this combo before and it has worked well for me.

The silde is really tight. When placed on the frame, pushing back it won't go past the mag well opening. One will find it impossible to slip a .001" feeler gauge between the slide and frame. I haven't checked the frame rails for parallel yet...hopefully tonight. After some thought, the idea of the spreader is getting lower on my list of options. My first steps will be check for high spots and parallel of the rails and then move to the lapping. I have done the lapping on snug slides before and it always works well. With this tough puppy, I may begin with valve grinding compound just to get things loosened enough to use the finer grit. I'll keep you informed.

June 8, 2002, 12:02 PM
Check the rails on the frame, new Essex parts are supposedly CNC machined, old ones were not. I have heard that some of the old frames and slides were poorly machined and not always in spec.

June 8, 2002, 02:38 PM
I had about the same fit when putting a NM slide onto an Essex frame. Lapping compound, a rubber mallet and some elbow grease.:D

June 8, 2002, 10:37 PM
is Diatomaceous Earth. Wouldn't surprise me to find out that JB Bore Paste and RemClean also share that ingredient. Regardless, it's not a bad choice for a lapping compound, although it won't bite nearly as hard as true lapping or valve grinding compounds in their various compositions and micron sizes. I had to lap together the slide and frame of my Caspian Officer's ACP, they're sold that way on purpose for a true custom fit.;)