Seafire: Years ago (spring of 2,003!) I tested different brands of 17 HMR ammo in my then brand new Ruger 77/17 V/T.
The Remington ammo (17 grain Accu-Tip) was THE more accurate in my Rifle (by just a tad/skosh). And I used that ammo exclusively up until 2,011 when Remington ammo became MORE expensive and harder to find and I chose to switch to the Hornady 17 grain V-Max's - as they were much easier to find on the retail market and also quite accurate in my now 3 guns in 17 HMR caliber.
I have, along the way, tried various ammunition made by Browning, C.C.I., Winchester and Federal if I recall correctly - and in various grain weights and bullet styles - I have not yet (but will!) try those Winchester 15.5 grainers you tried.
My NEF 17 HMR is also surprisingly accurate for as humble (cheap!) a Rilfe as it is!
My Ruger 77/17 V/T has shot test groups (5 shots at 100 yards!) as small as .502" - and that is simply outstanding accuracy for a rimfire of ANY caliber or of ANY manufacture!
Have you tried the Winchester 15.5 grainer on Varmints or small game as yet?
Come on spring.
Hold into the wind
VarmintGuy
