Colt Slides

[Peacemonger]

There are two commonly reported problems with recent Colt slides.

Some folks find the slide spring tunnels bored far off center. Others find the slide alignment is off center and tends to rub on the left hand dust cover. My gun had the latter problem and continued to have it after Colt's first repair attempt.

I am starting to think these apparently separate problem are actually degrees of the same problem - offsetting the spring tunnel in the slide.

I had thought the rubbing issue was due to the slide/frame fit being too sloppy. My recently repaired gun no longer has this problem. The slide/frame fit is fine but it still rubs and the slide is not centered in the frame.

I tore it down last night to clean it before retuning it to Colt and noticed the spring tunnel looked slightly offset. Not a lot, just barely perceptible. Measuring with digital calipers confirms it. The tunnel is bored wrong. Its offset to the right - the slide rubs on the left.

A sample size of one is no proof. I am wondering if other folks having slide rubs have this issue.

If so, then I am taking one of Colt's problems off my list. I'll no longer credit the problem to bad slide/frame fit.

[TacDoc]

My Combat Elite had an out of spec spring tunnel as well, but I think the real problem comes from angled FRAME rails. Mine were somewhat angled towards the right side.

The frame is the part machined with the new (still testing?) CNC's...

[Peacemonger]

TacDoc,

How do you detect or measure angled frame rails? I'm having a hard time picturing this. For me, that's not unusual. :)

I'm not quite sure I understand what you mean. Are you saying the rails vary in depth or that the rails are not parallel?

My frame seems straight using a simple stainless steel straight edge. My frame's tunnel has a consistent width as well. The rails' grooves have a consistent depth.

Again, this is only a single sample.

[TacDoc]

Rails not parallel and in the short side of tolerance. The frame rail width its supposed to be .750 and mine were .740. This combined with a loose tolerance slide may be the reason for the rubbing against the dust cover.

In my CE the right side is the offending one.

[Hawkmoon]

Rails not parallel and in the short side of tolerance. The frame rail width its supposed to be .750 and mine were .740. This combined with a loose tolerance slide may be the reason for the rubbing against the dust cover.

The frame rail dimension is supposed to be .751" - .003", which means that anything from .751" to .748" is in spec. A rail outside dimension of .740" is too narrow, but that doesn't provide any information about whether or not the two sides are parallel. Also, it is theoretically possible for the rails to be in spec and parallel to each other but not parallel to the axis of the frame.

All you have really documented are that your frame rails were cut too narrow. That would create a loose fit, unless the slide was cut correspondingly "fat," but it doesn't document any out of parallel condition.

[Peacemonger]

TacDoc,

On your gun is the spring tunnel bored dead center on the slide? Mine is slightly off, not a whole lot, and you need to look carefully to see it.

I am trying to imagine where the side thrust would come from in the firing cycle, assuming the barrel and guide rod/recoil spring are seated dead center in the frame.

I would expect torque from firing to cause the slide to drift rightwards in the rail grooves as the gun torques up and to the right.

It's interesting that yours is rubbing on the right hand side of the slide. The majority I have heard of seem to be on the left.

[TacDoc]

The frame rail dimension is supposed to be .751" - .003", which means that anything from .751" to .748" is in spec. A rail outside dimension of .740" is too narrow, but that doesn't provide any information about whether or not the two sides are parallel. Also, it is theoretically possible for the rails to be in spec and parallel to each other but not parallel to the axis of the frame.

All you have really documented are that your frame rails were cut too narrow. That would create a loose fit, unless the slide was cut correspondingly "fat," but it doesn't document any out of parallel condition.

This is what I meant. The inside part of the rails were parallel but oriented to the right from the long axis of the frame.

[boehlertaught]

TacDock/Hawkmoon, This is all amazing! I can't imagine how messed up the cnc machine is that crated the frames rails parallel to each other but not parallel to the axis of the frame. It would not take but a few thou to make the slid rub though. Keep us posted on how Colt fixes it.
Thanks

[Peacemonger]

TacDoc's gun also has the offset spring tunnel in his slide.

My theory (and I could certainly be all wrong) is that this is the cause of the slide rubbing.

Anyone else have a rubbing slide to check out?

[TacDoc]

This is my slide:

http://www.freeimagehosting.net/uploads/2a2dacc5f9.jpg (http://www.freeimagehosting.net/)

Yellow arrows denote the imperfections in the rails. The rails are narrower at the back of the slide. Red arrow shows where the sharp corner is located. This part is supossed to be round but is kind of sharp angled.

I regret not taking more and detailed pics of my CE before shipping it back. Didnt imagined this issue will turn in such an interesting debate. I though it was only my CE that turned out to be a lemon, but now I believe there is somthing big (and sadly in a negatine way) going on in the Colt 1911 production line.