On the shroud, I would go easy on the thread lapping, being sure not to use anything too coarse for the smoothing, so as not to degrade the fit while smoothing the surfaces, since the fit may be looser than is desirable to start with. There is a link between shroud fit in the bolt and accuracy that has been well established, and if the fit gets too loose in an otherwise very accurate rifle, you will loose accuracy. This is why Speedy suggested that Dave Kiff offer an over sized Remington shroud, that could be fitted for a closer fit. If you look on the web site, you will see it.
A few years back, I mentioned that I had disassembled the striker assembly of an old 722(redundant, they are all old) to check the fit of the shroud, and found that the thread fit was very loose. Not having a machine shop at my disposal, or the money to commission a custom fitted shroud, I looked around for a way to improve the fit, and decided to give plumbers teflon tape a try. While this did not slick up the action at all, it did take up the slack.
Some years later, a fellow had posted that he was having accuracy problems with one of two identical custom actioned benchrest rifles, that had both started out shooting good. At my suggestion, he tried several wraps of the tape the rifle's shroud threads. It fixed the problem. Later, when he checked the thread diameters of the two rifles' shrouds, he found that there was considerable difference. Evidently the one that had developed the problem was close to the edge on what would give the best accuracy, and wear took it into a fit that was too loose for best results.
Taking this one step farther, when Gene Buckys and Jackie Schmidt were both shooting Farley actions, Gene made them both custom shrouds out of something like graphite filled Delrin or Nylon (I forget). The self lubricating nature of the material allowed a closer fit in the bolt.
I believe that if you smooth the cocking cam and reduce the height of the cam side of the notch at the top of the cam, without moving the center of the notch, and use a good grease on the threads and cam that a lot can be accomplished toward smoothing a Remington or any action of similar design.
