I am considering having Clark build my next .45. They can use Caspian frmes and slides which I like. They also can weld on a "slide guide" which I have never heard of. Can anyone here explain it to me? Thanks>
It's a small yoke welded to the far end of the dust cover. Two set-screws are positioned so that tightening them puts upward, and because they are angled, "centering" pressure on the slide. If the slide/frame fit loosens, a small adjustment on the screws tightens it again. I think the screws bear directly on the recoil spring tunnel of the slide, and there must be some sort of work done to the slide to suit. I think there is a thread going already, with some pics; search "Giles slide" or "Giles guide".
Edit: it's actually on that other 1911 forum.
If you are using Clark, and one of their barrels, consider using a ramped model if you ever have any desire to play with 45 super or possibly 460 Rowland. It's a much stronger design, and having the that cut in your frame makes hot loads almost worry free.
It does limit "drop-in" barrel choices if you want to change later, but a ramp can be pinned into the frame and you would never know the cut is there. I have one caspian with a ramped clark, now about to get fit for a 460 Rowland, and another with the cut but pinned-up at the moment.
If you have no desire for "more" power, it might not apply to you. But since you are going to them, it's worth discussing.
I've owned several custom 1911's. The most reliable, accurate 1911 I've owned was a Springfield worked over by Clark. That includes Baer and Wilson guns. The Clark would feed anything, all the time, and would shoot. I mean really, really shoot! It did not have the extra slide modification/package. Personally, I think Clark is the "best available". Don't see them much here in Virginia. If my new custom 1911 does not run, that's where I'll probably send it.
Clarks does not make fancy or even pretty guns. Their guns tend to be simple and less detailed than other makers but mechanically there are few better. I have owned a few and they worked like sewing machines.