When I got my HMR some years ago (Savage 93), I tried every load I could find. In MY gun, the Winchester 17g Vmax stuff stood out not only for accuracy, but velocity consistency.
The general "knowledge" of the time was that all 17HMR cartridges were loaded in one or two plants: CCI /Hornady?, and only packaging was different in other brands. Delving further into why the Winchester stuff (yes, Hornady bullet) shot better in my gun, I dismantled a representative sample of all the loads I had tried.
The Winchester stuff had shiny ball powder. All others exhibited flake powder. This allowed me to conclude this stuff was not from the same plant(s). To this day, I do not think this ammo is "better". Here's why:
When I got my gun (as a gift, so no initial outlay of cash), I was somewhat disappointed in the accuracy considering all the lavish praise I'd seen and heard about this cartridge. With the gun obtained free, I did each and every improvement on the gun that I could imagine and/or afford: optics, bottom metal, glass bedding, bridge mount, custom trigger, etc., etc., etc. I did see results for my efforts, but not to the degree I'd hoped for. I kept hearing that "The CZ guns shoot better than any of the rest: If you are not happy with the accuracy in your heavily modified Savage, get a CZ!"
I had also come to the conclusion that the fault most probably did not rest with the guns, but the ammo: this was at first and for always a hunting cartridge. With this purpose in mind, no development was probably ever done toward target accuracy (more like .22 Magnum marketing strategy and development, and apart from the fine and expensive effort done toward .22 Long Rifle target ammo).
And so, In further experimentation, I invited each friend owning a .17 to come shoot for a day. Three Savages, two Marlins and a CZ showed up. We shot our own guns, and we shot each others' guns. We shot our ammo, and we shot each others' ammo. None of this 50 yard nonsense. All done at 100 yards off a hard bench in a heated cabin on identical targets. Zero wind that day. The guys who claimed, "Half-inch groups all day!" from their guns received gracious silence from the other participants when true results came in. Yes, there were half-inch groups. No, they did not happen even a measurable period of a day. There was a striking preponderance of groups that measured 1"-1.5".
The "winner"? A plain-jane, unmodified, blued, fat barrel Marlin with a maple stock, Tasco rings and a Bushnell scope. It belonged to girlfriend of the guy with the CZ: He gave it to her when he "upgraded". Hornady 17g Vmax ammo is what it liked. It didn't win by much, but neither did the CZ/Leupold rig come in third by much.
I'm convinced now, that if we were willing to pay 25-30 dollars a box for match-grade .17HMR (commensurate with price disparity of Eley Green Tag as compared to CCI Mini Mags in Long Rifle), we'd have those "Half-inch all day!" guns.
It ain't happenin'.
