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Discussion Starter · #1 · (Edited)
I started this as another thread originally, but now I'm wondering if maybe it belongs here.

I have an old Colt USGI. Pre-WWI.

I'd like to have better sights on it. So my choices seem to be to have new sights dovetailed and refinish the slide -- or just buy a new slide. I found this Colt Series-70 slide with fixed-sights already installed for $179. Seems like a heck of a deal. Should I be able to just drop it on? Or is it likely incompatible? Fitting of some sort required?

 

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WOW!

If you've atually got a pre-World War I 1911, I don't think I'd touch it. It must have considerable collector value, which would be destroyed by any modifications.
 

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The slide can be fitted by hand. You would have to find a slide that was a tight fit--a REALLY tight fit--and start from there.

I do it this way: When I fit a 1911 slide, I get one that will only slide on about 1/4 of the way.

I then coat the rails with oil and JB Compound.

Using a rubber mallet or rubber faced hammer, I then tap the slide on a bit further--not much, about an inch. Then, I remove the slide. More JB, then tap it an inch further than before. Off again, more JB.

I continue this until I have the slide all the way to the rear. Then, tap it off.

Remove ALL traces of JB. Secure the frame in a padded vise, then coat the rails with a good oil. Work the slide through its full range of motion, using oil only, until it moves smoothly.

You should have a fit now with absolutely no play up or down or to the side; however, the slide should move back and forth under its own weight smoothly.

That's the easy part. If you want to use a drop in barrel, feel free. However, there are other things that you must consider. These are:

1. Barrel-to-slide fit (barrel lugs and hood)
2. Barrel-to-bushing fit
3. Barrel, link, and slide stop pin contact (MOST IMPORTANT STEP FOR GOOD ACCURACY)
4. Centering and locating the barrel for a good firing pin strike.

Sounds like a lot? It is--and unless you're prepared to go REAL slow, and take your time to do it right, you might be better to send it off to have it done for you. It should not cost a lot, really--average about $200 or so in labor, plus parts.
 

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Discussion Starter · #6 ·
Can anyone confirm / dispute that a new Colt Series-70 slide should just "drop right in" to an early Colt US GI 1911?

I'd hate to order the slide and then find out it's not compatible at all and simply can't be used.

I gather Series-80 slides have the little hole for the firing-pin stop, but the only thing I'm aware of with the other slides is different factory sights...?

The frame / rails should be the same between 1911 / 1911-A1, right?

Mike
 

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Michael, very seldom will a slide be a perfect fit on another gun. Sometimes, they will slide right on with little or no play; if so, count yourself lucky. Sometimes, they are WAY loose, other times they are a bit too tight.

If tight, they can be lapped on using the procedure I described.

If loose, you will have to have it fitted, or live with it.

The differences between the 1911 and the 1911A1 are:

1. Trigger relief cuts
2. Slightly modified grip safety
3. Arched mainspring housing (I think).

Other than that, the frames are dimensionally the same. Any 1911 slide should work on your frame.
 

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Discussion Starter · #8 ·
OK, thanks. That's what I thought.

Now I just need to decide -- do I gamble that I'll be "good enough" just slapping the $179 slide one there? Or spend another $200 to get it fitted. At that point I'm up to $379, versus just buying a new SA Mil-Spec for $399....

:confused:

Mike
 

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If the original slide fits well why not just send that one out to have sights installed on it? There are a few sight combinations that are very resonable, work well and might be more cost effective.
Just a thought!

Ed
 

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Discussion Starter · #11 ·
I was under the impression I couldn't get new sights installed for less than $179.

Especially if I went with dovetailed sights and had to get the slide refinished too.

I've also heard these old slides were made of pretty soft steel. I hate to sink a bunch of money into the current slide and then have it crack on me.

Mike
 

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Discussion Starter · #12 ·
I was thinking $179 for a new slide with sights already dovetailed was a darned good deal.

I guess I hadn't actually priced them. Just sounded too good to pass up. If it's not an awesome deal, or it's likely to come around again I can just stick this old Colt back in the closet and re-visit the issue at a later date. It's more of a "something I'd like to do some day".

Mike
 
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