Fitting S_I slide

[LGator]

Another post discussed fitting a 1911 slide to a frame by using JB lapping compound, beating the slide on with a mallet and then working it until smooth.

This might be a dumb question, but how do you hold an S_I frame in a vise to do this? Do you remove the lower plastic section and just put the metal part in a padded vise? Would it be better to get a mag well filler and put the whole thing in a vise. Thanks in advance.

-LG

[TMC]

If your going to put it in a vise, remove the grip and clamp the frame in the vise. If its a "white" frame just use alum. jaws. A mag filler will keep you from crushing the grip but if the grip is the only thing in the vise and you beat the slids on you surely crack the grip.

Before you start beating you need to take some measurements to see where the greatest interference is. I have found that sost of the time the frame rails are wider than the slot in the slide. Use calipers and file a little and then measure at both ends of the frame. Keep it even and go easy. When you get to the point where it will go on a little them start tapping. Adding compound at the start will only make it harder because the compound takes up space. Use some oil or slide glid at first. Once it you can tap it all the way on and off then add compound to lap it so it will go back and forth smooth.

[Jasonub]

i cant think of anyone beating on an s_i part.

mine was cut by a cnc machine then hand lapped.

[Brazos Custom]

It needs to be fit closer before you put it on the slide. If you have to beat it on you are just going to gall the slide or frame and it won't ever fit right. Caspian slides/frames are usually cut within 0.001 and you can get away with this. STI frames/slides usually run plus 0.006 both ways. That is a lot of metal to file off and still be square.

[LGator]

Good points made by all. I don't have the slide yet so I'm not sure how much, if any material I will need to remove. I planned on ordering a new STI slide from Brownells this week and just wondered if there was anything else I might need.

I guess I should get the slide first to determine if this is something I want to tackle myself.

Thanks again.

-LG

[TMC]

I guess I should get the slide first to determine if this is something I want to tackle myself.

When in doubt, go to a pro. Its worth more than they charge.

[EricW]

If you have never tried to remove several thou of steel before and do a neat job of it, you're in for an experience. This sounds like a job for a surface grinder if there ever was one. It'd be hell trying to save a few bucks and end up sending the sucker out for an accurail job.

[shred]

I may have been the one that posted about the slide beatings. Bob's right, you need to fit it most of the way on other ways before you even think of doing that. You also have to be careful on dimensions so you aren't lapping the wrong things or beating a wedge into your nice slide.

Just getting a slide and frame and whanging away is not the right way to go about it.

[BEDELLCUSTOM]

bob is correct, there is quite a bit more metal to remove when you are fitting an STI slide and frame, any builder like myself has the equipment to do it properly. it is almost impossible to fit it correctly by hand and keep everything square. you may be better off buying an STI prefit slide/frame kit or sending it to a gunsmith to have them fit it for you. i've seen plenty of people attempt what you want to do and it can get pretty ugly and expensive when you start wrecking parts.

[mcoliver]

And I thought the only thing needing beating is when installing rear sights.