MedRiver: I have a pair of Varmint Rifles in 17 Remington Fireball (actually one was a custom built 17 MachIV - which is the Fireball before it was commercialized) and a pair of Varmint Rifles in 221 Remington Fireball.
It is VERY difficult for me to recommend one over the other - but for your "fit in" circumstance and for your uses I would venture to the 17 Remington Fireball!
I have killed large Varmints (Rock Chuck, Badger and Coyote) out to 450 yards with my 17 MachIV and 17 Remington Fireball using the amazing 25 grain Berger bullets!
Best of luck to you with whichever you choose.
Hold into the wind
VamintGuy
