I only shot two groups as posted above, so I'm just getting started with 4320. I'll work up to 24 gr. and give that a go.
I don't have any Remington primers, only CCI 400s and also some Winchester small rifle primers. I may have a few Federal Match primers.
A local gun shop has, or at least recently had some N140, but as I recall it was pushing $50 a pound, slightly under. That's pretty stiff, but if it would shoot tiny groups, I wouldn't hesitate.
I'll chronograph my 4320 loads later, but I was figuring it would be somewhere around 3800 fps, maybe even a tad bit less, that according to data in a Hodgdon manual. Would be a nice surprise if it shoots faster.
I'm hoping to try this bullet / load combination on a coyote soon (got one coming regularly to my bait site) combined with a home-made night vision outfit I put together this summer. I admit to being a bit nervous over the idea of taking a coyote with a small 25 gr. bullet. I'm a bit like Elmer Keith in that I tend to go higher rather than lower, so the .17 is taking some getting used with the thoughts of that tiny bullet.