[ACP]

Correct me if I'm wrong... early slide lock (slide locks open with half a full magazine) is usually a sign of:

a) a worn slide stop.
b) worn magazines.

And if I just happen to have a new Ed Brown slide stop, that can be dropped in or fitted to correct the problem; and if I have new Wilson and Metalform magazines (7 and 8 rounders), that should solve the problem too?

FYI this is a 70 Series Colt Combat Commander.

[Walt Sherrill]

It could be that...

It might also be mag feed lips that have been damaged and let the follower rise farther than it should. [Just reread this the following morning. Nope. Doesn't apply. I'll learn not to reply when I'm tired.]

Or a slide lock spring that's not putting tension on the slide lock, letting it move too easily.

Or the tip of out-of-spec ammo nudging the slide stop as they come up the tube. (This is more likely to be the case with a double-stack mag than a single stack, however.)

[fastbolt]

This problem was resolved in my early 70's series Combat Commander when the slide stop had a dimple machined into it with a moto-tool ...

I've also seen a simple angled inset cut horzontally across the proper level of the slide stop rear face, with a triangular file, which served the same purpose of catching slide stop plunger if the slide stop was just being "nudged" upward by recoil forces, or a wide bullet ogive, instead of being lifted by the follower ... which was powered by the magazine spring.

Newer design slide stops often have notches, "shelfs" & bevels incorporated into this same area to perform the same function ...

In older times if the slide stop tip was hitting against the sides of bullets as they rose upward under recoil, the tip could be relieved a bit to allow the bullet noses to clear, but not so much that the follower missed engaging the slide stop ... Easier to provide some more "bite" for the slide stop plunger, though, as it's never easy to replace metal once removed.

[Lone_Gunman]

I used a Dremel tool to fix this problem...

Take out the slide stop, use a diamond bit in the dremel, and drill out a very shallow hole in the slide stop where the plunger makes contact.

This fixed the problem completely in a lightweight Springfield Officer's sized 1911.

The problem you describe seems to be more common in compact, lightweight guns than in full size 1911s. Its easy to fix though

[PCRCCW]

The slide lock spring isnt the problem.
You have a little large bullet that is just nudging the slide lock.....
Usually you can see where its rubbing....just file it a tad and your in business.