Unfortunately (or fortunately for our farmers) Gophers are hard come by here in Southern Ontario. I have had the good fortune to have hunted them on Comunity Pastures in Sask with my cousins some 40 + years ago.
For Gophers, at 100 yards, honestly, I would stick with the good old .22 LR. Nothing fancy, but on a quiet day, you can hear them hit very solidly. Ammo is way cheaper too.
We still have a few ground-hogs here and I used a CZ455 17 HMR for part of one season and while consistent accuracy was not an issue, clean kills were when you got out there at 150-200 yards. I went back to 85 gr HP out of 6.5 x 55 for ground hogs.
For Gophers, at 100 yards, honestly, I would stick with the good old .22 LR. Nothing fancy, but on a quiet day, you can hear them hit very solidly. Ammo is way cheaper too.
We still have a few ground-hogs here and I used a CZ455 17 HMR for part of one season and while consistent accuracy was not an issue, clean kills were when you got out there at 150-200 yards. I went back to 85 gr HP out of 6.5 x 55 for ground hogs.