[Freebore]

You gotta love a question like this......you'll get as many opinions as there are cartridges.

So my opinion is:

...22LR, probably the best (fun,target, plinking, hunting, cost effective, etc. etc.) cartridge ever made, will most likely still be around after the human race is long gone.

...17HMR, a super high velocity rimfire which has excellent accuracy, good dispatching abilities (within its range), and no recoil or big bang. A fine cartridge that will be around for a quite while due to its popularity with the user base and manufactuers.

... 22 Mag, Nice cartridge, like the 17HMR it provides good accurcy, no recoil, or loud blast, and good performance, again, because of its popularity by the shooting fraternity and manufactuers, it is obviously holding its own in the world of rimfires.

...17 Mach II, kind a different story, while it may have some good points, the most negative issues are the three cartridges above, they are far more popular and effective in their respective classes, based on this I feel the Mach II is headed down the same no marketing/low sales road as many (now obsolete) fine cartridges have gone.

Remember, Its all about sales/marketing, not performance that keeps a cartridge alive.

As for Coyotes, (mentioned somewhere above) let's be humane, use a cartridges thats effective for the shot taken, not one that "I think will work", all of the rimfires are questionable at Coyote shooting distances, I would not take a fair shot at a Coyote with anything less than a centerfire 17 or 22 cartridge.