[Jeff Higgins]

I'm sure it will come as a surprise to exactly no one on this forum that I'm a bit of an airgun enthusiast. I own and shoot a variety of rifles and pistols, from vintage American pump-up pneumatics to modern high end German and English spring piston guns.

I place airguns in two very broad categories. My first category are those that can be fired without the need of any support equipment. My second category are those airguns that require support equipment in the form of a secondary air supply or secondary pump.

My first category includes the traditional American pump-up pneumatic, like the venerable Sheridan Blue Streak, the old Benjamin, the Crossman 760, and the like. I believe the only one still available is the Crossman, which is no more than a cheap plastic "kids' gun". All of the "adult quality" guns of this type are long since out of production, although they can be found on eBay, Gun Broker, and other internet sources.

None of these are powerful enough to reliably dispatch a 4-12 pound groundhog. I have three vintage Sheridans and one Benjamin, all modified by Tim MacMurray of MAC1 Airguns to better than double their original power output. Even at that, they achieve maybe 20-25 ft lbs of muzzle energy. By way of comparison, the lowly standard velocity .22 LR achieves about 140 ft lbs. Not even in the same league. Oh, and these pump-up guns are quite loud. Nowhere near .22 LR loud, and probably not loud enough to scare even the most gun shy of dogs, but they do have a pretty good little crack to them. But, well, probably immaterial, because they still just don't have the oomph necessary.

More powerful, and still available, are the various higher end "springers", or spring piston guns. These are cocked by breaking the barrel, or with a side lever, or some with an under lever. Some of these are available in .25 caliber, which I would still consider to be marginal of a 4-12 pound groundhog. But, well, if you want fully self contained, this is the upper limit, power-wise. And, incidentally, these "springers" are not loud in the least. I have a suppressor for my Weihrauch HW80, but it really makes no difference at all. I can't see any dog being frightened by one of these even unsuppressed.

My other category includes the "PCP", or Pre-charged Pneumatic. These carry an air tank that holds enough air at high enough pressure to allow for several shots between the need to recharge from some external supply. In the old days everyone just used a SCUBA tank, getting them refilled at dive shops. Today we have dedicated tanks just for these rifles, much lighter and more compact, that makes carting them around far less of a burden than it used to be. In addition, we have high pressure pumps, like bicycle pumps, that can also be used to recharge these.

It's in these PCP rifles where we find some serious airgun power. Guys hunt deer with them (but that's a topic for a different day). There are many available in .25 caliber and larger (.30 would probably be good for groundhogs) that have plenty of power. You can spend some real money on these, though, and their support equipment isn't cheap either. Think several thousand dollars for the good stuff.

If it were me, I would be taking a good look at one of the better .25 caliber springers, like from Weihrauch. Not cheap either, at somewhere in the $700-$900 range before you even put a scope on it, but definitely of "heirloom quality". I use Weaver scopes meant for the .22 LR on those that I do scope, avoiding the dedicated "airgun" scopes. There is an issue with the "reverse recoil" destroying most scopes, but Weaver (and others, like Leupold) rate their ".22" scopes for this use. I destroyed a lot of "airgun" scopes early on, but my current crop of Weavers are now well over ten years old, with thousands of rounds fired, and they are holding up just fine. And they are not expensive, either.

And yes, you can look at other things, like crossbows, bow and arrow, etc. Maybe fine for deer hunting, where their "vital zone" is larger than an entire groundhog, but (at least in my opinion), completely unsuitable if you really want to kill groundhogs. They are small, skittish, low to the ground, and hard enough to hit with a rifle. I'll just about guarantee that those offering these recommendations have never actually tried it.

Anyway, those are my thoughts. I've killed countless rats, possums, bunnies, crows, squirrels, and the like with air rifles. Nothing as big as a bull groundhog, though. I think I would "need" a new air rifle for that.