As bunny busters, we spend lots of time on our gear, and even more on our dogs. These two get us close enough to roll these little critters but in the end, its the shotgun that does the work. With that in mind, let us talk about the best scattergun for the job.
The good thing about bunnies is that they are the very definition of small game. In the Eastern U.S., where dogs are used primarily, a 4-pound rabbit is in the same category as a 16-point buck or a 30-pound salmon. Western Jacks get bigger of course, but for what we are dealing with, just about any caliber shotgun shell from .410 to 12-gauge will work. Of course, the larger the shell hull, the more shot capacity we are talking about. For instance, a Remington Express Long Range Ammunition 410 Bore 3" shell in #6 only has 11/16 oz. of lead shot. The same maker's 12 Gauge 2-3/4" shell is crammed with a full ounce of shot, while giving you an extra couple hundred feet per second velocity, meaning you have a good 45 percent more chances to hit a rabbit with a 12 gauge than a .410, especially at range. You can take that formula, break it down for 16 and 20, and see the same pattern develop.
Me, I cut my teeth with a 16-gauge and personally know of an old timer that can pop a running rabbit with a crack barrel .410 out to 20 yards or better, but I find the best results with a 12. The math makes sense.
The funny thing about my dogs is that I tend to get 2-3 rabbits run out of a briar patch at a time, often scattering in different direction as if planned out. Now the chances of me getting more than one of these are slim. Just admitting my own faults. However, with a single barrel or hinge-break, the chances of even getting a second shot providing I miss the first, are nil.
Likewise, I've hunted with a pump several times and just can't get the knack of a quick enough follow-up shot while keeping the bead on a cotton tail to make it a viable option. This leaves double-barrels and semi-autos. The double-barrel, be it a side-by-side or over/under, have the benefit of being quick up to the shoulder, and a little lighter on those long days in the field. I once borrowed a friend's Ruger Red Label that I liked so much it led me to buy a well-used but not abused Browning Superposed, which was actually a little lighter as well. Don't let these "old school" guns fool you. They are just as effective in stocking the pot today as they were generations ago.
Semi-autos are also nice. Like the double-barrels, they provide a very fast follow-up shot. In cases of more modern designs that use inertia, such as the Benelli and Beretta models, they are actually even a little faster. However, keep in mind that these designs, especially if you are a swamper rabbit guy, are susceptible to grime and grit if dropped in muddy, nasty areas. Moreover, they add a little weight, but that can be offset with synthetic stocks.
A lot of gents will be very adamant that you have to have those super long barrels, the 28 and 30 inchers, to be able to reach out and touch a rabbit on the run. However, studies show that even riot-length (18-inch) barrels can drop small game at comparable ranges. Don't get me wrong, barrel length does have an effect on velocity, but in the patterns and ranges we are talking about for, even those short cop-barreled guns are rabbit pieces to 25-30 yards.
With that in mind, you can cut back a little on that barrel length for ease of carry without giving up your harvest. Besides, use of a full choke can help tighten it back in if going shorter. Most makers, especially Remington, offer a wide variety of barrel lengths you can choose from.
Don't get caught up in the name on the barrel of the shotgun. With today's CNC manufacturing techniques, most of your big name scattergun makers are roughly comparable in quality. Rule of thumb, as long as it is a recognized brand, odds are you can trust it. Sure, a $125 NEF/H&R crack barrel is going to cost far less than a $900 Beretta, and the fit and finish are going to be far different, but each will function and do what they are supposed to. And guess what? If you take each one and fire a single shot at a single clay rabbit on the range at 20 yards, odds are you will have about the same chance of hitting or missing it.
My personal choice
I've gone after bunnies in a dozen states with probably twice as many guns. My personal choice: I use an older Remington 11-48 semiauto in 12 gauge with a 2.75-inch chamber. The only modifications I have done to it was to swap out the original wooden furniture (after the forearm cracked anyway) with black synthetic after markets which had the side benefit of dropping the weight a few ounces. Then, I swapped the 28-inch vent rib with an unribbed factory 26 to make it a little handier in the field. My choke, is a Rem Full and it patterns nice on rabbit targets to 35 yards with green and yellow #6. More often than not, I can usually bag the bunny with either the first or the second shot even with my bad eyes and mediocre skills.
Of course, your mileage may, and will vary, and with that in mind, drop your personal choice in the comments below.