Have a Lefever G with a grip cap that’s too loose, but the screw is well timed. What’s the supported method for securing the cap and ending up with a screw that’s still timed. Same question could apply to buttplates, etc.

Another 1/2 turn of the screw... removing additional wood by sanding or scraping if necessary to reach that point without over-tightening and cracking the grip cap.

A cheap and dirty way would be to shim under the head of the screw with teflon pipe tape or very thin conical washers made of thin sheet copper or aluminum.

Thank you. I think I got the idea.

There are a number of ways to adjust screw timing, these are a few methods I use that do not need too much effort on my part and each in there own way perfectly cures the problem.
Simplest of all for countersunk and raised countersunk screws is to use a countersink bit turned by hand to remove just enough material from the countersink to time the screw correctly.
For domed head screws spin the screw in a drill chuck and use a file on the head's flat surface to remove enough material to get the timing correct. This takes time and by far the method I dislike but it works well.
The last method appeals to me for its simplicity and it works well each and every time, though I will say don't knock it until you have tried it.
This simple fix is not from the gun trade but that should not matter, all it consists of is some strands of wire wool wound on the screws shank just under its head. By removing or adding strands of wire wool you can get the tightness and timing perfectly, also once done it is a permanent fix and easily reversed with no tell tail signs it was ever done. Sneaky, fast, and appeals to my lazy streak!

I like the sneaky, fast approach. Thanks.

You do not want to remove wood. That may result in poor fitment of the geip cap on the stock.

Brian does some really great wood work on our fantastic doubles. Thanks for any advise sir! Hope he can help Bill

You might try driving a small peg into the screw hole, the screw might pull up tight then.
Mike