I received my Ruger #1 in 450/400 NE 3" recently. After reading the instruction manual, I noted the recommended procedure for windage adjustment on the rear sight was, of course, to drift it right or left as required. However what Ruger neglected to include in their instruction manual was that on this particular model, there is a rear sight blade lock screw on the barrel rib immediately forward of the rear sight that locks it in place and must be removed prior to drifting the rear sight and tightened prior to shooting the rifle. Failure to loosen or remove this rear sight locking screw could result in cosmetic damage to the rifle when attempting to drift adjust the rear sight.
I called Ruger customer service and explained that my instruction manual not only did not have the 450/400 NE 3" caliber listed on the front page with all the other calibers ever chambered in the # 1 rifle (my first clue) but also it did not contain the correct rear sight adjustment procedure. The customer service response was to send me a copy of the manual that I already had. I then called the Ruger technical services department and explained the problem. Their response was that they (Ruger) probably missed that one tidbit of important information and maybe it would be covered in the next printing of the Ruger #1 instruction manual or basically tough luck next case.
So this posting is a note of caution to all owners of the standard Ruger #1 in 450/400 NE 3" concerning proper rear sight adjustment.
On a the same note, the Ruger Hawkeye African & Alaskan Model M77 handcranks have a rear express sight that also has this same setup with a rear sight blade locking screw. The correct drift adjustment procedure requiring loosening of the rear sight blade lock screw is in their respective instruction manuals. It is as follows "Lateral windage adjustment is made by loosening the rear sight blade lock screw (located in front of the rear sight blade) and carefully move the the blade in the direction you wish to move the bullet point of impact. Tighten the screw before shooting the rifle. Repeat as necessary until the rifle is zeroed."
The Lipsey Ruger #1 in 450/400 NE 3" also has this rear sight setup and it too has an express rear sight. I don't have access to a Lipsey model Ruger #1 450/400 NE 3" instruction manual but I will wager that it also contains the correct rear sight sight drift adjustment procedure.
This got me thinking, if these rifles all had the same rear sight setup as my rifle and the only difference is that they had express rear sights and mine has the cheesy Williams folding rear sight, the express rear sight from a M77 Hawkeye African just might fit my Ruger #1. I ordered a Ruger Hawkeye M77 African express rear sight, Ruger P/N D07725HM, in hopes that it will fit. It only cost $16.25 including shipping so it is a cheap gamble. The only thing left would be to get the correct NECG Ruger #1 front sight blade in the correct height for proper sight adjustment. I'll let the forum know how this turns out.