CottonMcKinght,
You are 100% good to go!
Medicdave and Scorpion8 are correct. We don't all need big brother.
Ruger is sued regularly by customers who do not have the good sense to read directions and take responsibility for their own actions and therefore become victims of their own lack of initiative.
So it needs to be recognized that whatever Ruger communicates about its products is directed to that lowest level of its customers as directed by their legal advisors. That does not automatically render all the rest of us stupid.
Firearms are not rocket science and reasonable people who exhibit reasonable common sense can safely perform tasks within their skill levels. That's what you have done and in addition sought practical advice. You are to be commended for your initiative, 100% effort, and success; you do not need to be told the "sky is falling" to scare you.
I'll gladly include my notes but I believe they're a bit redundant after your comprehensive efforts.
WHICH MODEL SINGLE SIXES CAN SHOOT MAGNUMS:
All New model single sixes can use interchangeable cyls.
And all old models with 3 screws, if over the serial # 150,000. Before that # the barrel bore was sized for 22 LR only and the 22 Mag bullet is slightly larger.
Guns are all just marked ".22 cal." except old model 'magnum only' and 'magnum convertible' single sixes marked "Win. .22 RF Mag. Cal."
Only old models prior to c. serial # 150,000 are not considered convertible because they do not yet have the compromise bore size of .224".
The new and old model cyls will both work. In general the only difference is that OMs are fluted and NMs are non-fluted with a 22 mag stamping.
TO GET A CYLINDER OF PROPER SIZE:
You can purchase a used Mag cylinder usually around $75 more or less, on the forums, ebay, Gunbroker, etc. In 30 years I have never installed one or heard of one that did not function and "time" correctly. They are assembly line produced to a common plus or minus tolerance. The exception and only important issue is that it has enough overall length for your frame at the front hub which is fit and sized to each individual frame window. If too long you can dress it down and is simple to 'fit' with a little stoning, usually under .005", that's not a lot. To have a gunsmith do it would be a minimal charge if you're more comfortable doing it that way.
You should take an overall length measurement of your LR cyl with a dial caliper in .001 of an inch and seek one the same length or longer (1st photo). A cyl with a gap as shown at the bottom arrow, in the 2nd photo below: will rub on the end of the barrel at the top arrow because it will move back and forth in the gun called "cylinder end shake" in gunsmith terms.
Photo courtesy of “rugerguy"
One solution for cyls that are too short is a tig welded bead and then filed to fit frame. The other two are drilling out the hub, turning and press fitting a longer one, or drilling out and installing a Colt cyl pin bushing. The advantage of the Colt bushings is that you can use the cyl in more than one gun by having cyl bushings that fit each frame.
RugerForum.com ? View topic - Is welding stainless possible?
Photo by NitroAcres
Note: Magnum 22s are expensive, but the mag cyl will also shoot 22 Winchester Rim Fire ammo which is a bit cheaper with similar performance.
Shims: free shipping,
TriggerShims Brand Shim Kits
WHICH CYL WILL WORK:
NM 22 LR cylinders are not all the same. Early NM cylinders are the same as OM cyls.
You need to date your gun or provide a serial # and we can identify when it was made.
Old Model and early NM 22 LR Cylinders look like the one on the left with the firing pin groove.
Post c. 1975-1976 New model 22 LR cylinders look like the one on the right, no firing pin groove. Either is correct for NMs depending on the vintage.
RATCHET BOSS DIAMETER CHANGE NM:
Fairly recently and coinciding with single ten introduction post 2010, there was a change to a smaller ratchet boss diam. (same size as the .32 Mag cylinders have had since their introduction in 1984). Personally in all my testing I have found the two different ratchet boss sizes to be interchangeable. But I can't guarantee it in every case.
Late NM .22s have a ratchet diameter of .560” and all the rest of the NMs and all OMs have the large diameter ratchet of .622".
The only things to be concerned with are the OAL of the cyl and the ratchet boss size. Just looking for a NM cyl will not guarantee one that will work.
Fitting cyl or cyl bushing to frame:
This normally done in a lathe but we don't all have that luxury.
1st check bushing length end to end at 4 places around it to be sure it's square when you start. If not, square up the offending area.
To file bushing, clamp in vise with end to be fitted pointing up and level using a level. Coat with black magic marker. Use a medium cutting flat file wide enough to cover the end of the bushing. Use in a draw filing position, parallel to the vise and workbench with one hand on each end of file. Push it away and back towards you concentrating on "feeling" the file surface staying flat on the bushing surface as you 'draw file' away from you then back towards you; back and forth. Check the black ink often to observe if it's being removed evenly. Re-coat with ink and keep going. Check bushing length again in 4 places to be sure it's remaining square. Put in cyl and check in gun before you think you've taken off enough, just in case measurements might be a little off. Clean file every few strokes so you don't get any galling or gouging. When done you can smooth up file marks with 600 grit paper wrapped around the flat file using same draw filing technique.
Hope this is helpful,
Jim