Need help fiiting slide to frame

[bbg]

Hello everyone, I am new to this and I am trying to fit sti slide to sti frame. I have a couple questions:

1. It looks like the bottom of the slide has too much material ( you can see a small gap in the first picture ) How do I manually remove material from the bottom of the slide? Is there a jig for this? I have the matrix precision jig but my file sticks out too much. I can try to modify the matrix precision jig but I want to see if there is any other option.

2. in the second picture, there is a small step under the rail. What is that for? The slide will move up a little when it travels backwards. Should this step be filed down? Can I remove the material from here horizontally instead of removing from the bottom of the slide?

Thank you for your help.

[RonPogi]

Put sandpaper top of a flat surface like a glass  and run your slide backward and forward.

[ChuckS]

I'm no expert but comparing that frame to my STI, I would venture to say that step is the result of some machining problem.

[ACree]

BBG,

 

The raised portion you are referring to in the second picture is to provide some clearance between the bottom of the slide and the dust cover and even the integral plunger tube housing. You do not want the bottom of the slide rubbing along the top of the dust cover or the plunger tube housing. It looks really cool then the slide melts into the frame (especially the full-length dust cover frames), but this is not a good thing. It also is extra material in case you need to re-cut the frame rail to open it a bit to accept the bottom portion of the slide rails.

 

In regards to the question you are asking about removing material from the bottom of the slide, I would suggest mapping out all of the measurements for the frame and slide rails first if this hasn't yet been done. Those measurements will help you, as help us, to tell you where to begin to remove material. I have attached a pretty common slide and frame measurement sheet to help out if you do not already have one.

 

Andy Cree

Edited September 9, 2017 by CCG

[bbg]

Thanks everyone. I really appreciate your help.

[drewbeck]

You need to remove material from the slide rails so they fit in the frame ways. Don't remove that step, in the frame or mess with the frame dimensions in any way for that matter.  

 

What you really need is to measure the slide rails and frame ways and see how much you need to remove from the bottom of the slide.  A caliper is not good enough in my experience, you really need a micrometer. Brownells sells a rail mic but they are $279 ish but if you search eBay for a "can micrometer" you'll find the same thing from starrett and can pick one up for around $50-60 if you're patient. A "groove micrometer" can also be used to accurately measure but they are generally more expensive. 

 

I fit fit my first slide without anything but a caliper and you are kind of shooting in the dark without being able to accurately measure the parts. It turned out ok but in my opinion a jig is worthless if you can't accurately measure anything and you're better off with a rail mic and sandpaper/glass than you are with a mill without a mic.  

 

I now now have a mill but prefer to still use hand tools and good measurements to fit the frame and slide.  It's a hobby and I'm fine with it taking a little longer to get good results with hand tools but if you can't measure it accurately you'll have more slop than necessary.  The gun can still be accurate but it'll be more difficult to make it happen.

my biggest advice is to try to figure out where it's bound up and then sleep in it for a night, then start removing material. In that time period you'll think about the things to double check before you cut something that isn't really the problem

[Phighfill]

What would happen if you remove too much material from the bottom of the slide.  Mine is somewhat loose, can that be fixed or do I need another slide?

[Vmax606]

23 hours ago, Phighfill said:

What would happen if you remove too much material from the bottom of the slide.  Mine is somewhat loose, can that be fixed or do I need another slide?

 

IF the slide and barrel are still in good condition, check out ACCU-RAIL. The slide will move sooo smooth and hardly any play at all.

[HOGRIDER]

23 hours ago, Phighfill said:

What would happen if you remove too much material from the bottom of the slide.  Mine is somewhat loose, can that be fixed or do I need another slide?

https://www.1911forum.com/threads/proper-slide-to-frame-fitting.1001118/

 

[barry]

I normally take material off that step on the frame usually. 002".003". Has worked well on the 20 or so that I've done. But I do have a full size mill. I have found a quality digital caliper is sufficient.  

[wanttolearn]

HI, take a peak at this gentleman's series of videos in which he instructs and builds 1911s....there are quite a few videos that nicely illustrate the process. here is one for example

 

Edited October 20, 2023 by wanttolearn

[ltdmstr]

Typically you remove material from B on the frame and D on the slide (using above diagram).  And that's it.  You do not touch the step on the frame.  And if the parts are within spec, you shouldn't have to touch any other surfaces. 

 

Re: Accu-Rail, be aware that they hog out a bunch of material from both the slide and the frame.  Once that's done, the parts are useless without the rails.  So, you'll never be able to fit another slide unless that one is also machined for Accu-Rails.  Just mentioning that because they don't tell you up front, and several people I know who've had it done were not happy to learn that after the fact.

[shred]

On 10/19/2023 at 3:08 PM, Phighfill said:

What would happen if you remove too much material from the bottom of the slide.  Mine is somewhat loose, can that be fixed or do I need another slide?

There's several of old-time gunsmith 'tightening' tricks that can be used before Accu-railing.  They won't last forever, but are a lot less invasive.