Helping You Get the Most From Your Hunting Dogs
You and the 12-Yard Bird - Part IIby Bill Hanus
Help! Help! . . . you're choking me! The fact is that we're shooting guns that are too tightly choked. In the pre-choke tube years -- say fifty years ago -- the problem could be dealt with simply by taking your trusty hack saw in hand and removing two or three inches off the muzzle of the offending, too-tightly choked shotgun. Viola! . . . you and your cylinder-bored shotgun are ready to take on the world. But times change with shooting sports.
Today, not only do the bulk of the shotguns sold have screw-in choke tubes (commonly IC-M-F) -- but ammunition makers are creating shotgun shells that are technologically light years ahead of the paper-wadded shells of yesteryear. This greater efficiency can be the ruin of your 12-yard game.
If you are shooting pointed birds in heavy cover, you're going to see a lot of 12-yard birds -- and maybe that's all you see. Lotsa' flushes but not lotsa' shots.
Here's why -- we took BSA's new Royal model 20 gauge side-by-side out for a spin and shot some patterns with the factory-supplied Improved Cylinder and Modified choke tubes. It doesn't take a lot of cardboard to shoot 12-yard patterns with IC and M choke tubes in the gun. At 12 yards the Improved Cylinder choke tube had a 14" pattern and the Modified choke tube had a 13" pattern. So into a circle the size of a medium pizza, we put a couple hundred pellets (would you believe 359 No. 8's in a 7/8 oz. 20 gauge load?). The small pattern makes it easy to miss -- but then connecting with this pattern ain't all it's cracked up to be either.
In theory, an Improved Modified choke in a 20 gauge barrel is defined as having a maximum of .007" constriction more than the bore diameter. That's the theory, but you have to understand that on production guns, you almost always end up with more constriction than advertised.
This error in shooting sports is compounded by advances in the development of shotshell ammunition.
Baschieri & Pellagri, who is probably best known to bird shooters for their 16 and 28 loads, markets a 12 and 20 gauge shotshell ammunition line which features the Gordon System of ignition that has helped B&P win gold medals in competitive shooting. This probably requires a word of an explanation because it epitomizes the kind of creative thinking that contributes to the efficiency of shotshell design and usage today. You can learn more at: bandpusa.com.
The Gordon System is a different way to make shotshells. The inner base of the hull is a progressive dampening spring that operates when the shell is fired. This has an immediate benefit: it works along with a collapsing base wad to absorb recoil by reducing operating pressures. It's like having a shock absorber in front and a recoil spring in the rear. The key benefit here is that you can operate at lower pressures -- which translates into less shot deformation -- which means better patterns and less recoil -- hence less muzzle jump, so you don't have to look all over the sky to take a pair. It means you can ratchet up the shot speeds to buy an extra five or ten yards of range, say out to 30 or 35 yards when you have open chokes in the gun without boosting operating pressures or felt recoil.
What we have here is a situation where we're pushing modern shotshell miracles -- from B&P, Federal, Fiocchi, Remington and Winchester -- through an arbitrary choke choice that was designed for shotguns with half-inch forcing cones, cardboard shells with fiber wads and chilled shot in use a hundred years ago!
Briley to the rescue! While it was still on the drawing board, BSA wisely decided to use the semi-standard Beretta threading for their choke tubes, which meant that the BSA Royal model test gun was able to benefit from Briley's (800/331-5718) research and the development of their Diffusion™ choke tube (a skeet choke tube, cut with a one-turn-in-14" rifling). The idea is that the rifling imparts a spin to the shot as it goes through the tube en route to the bird. The following chart shows how the Briley Skeet ($35) and Diffusion™ ($55) choke tubes compare to the BSA factory Improved Cylinder chokes at 12- and 20-yard distances:
|Pattern diameter (in inches) at:
|BSA-supplied Improved Cylinder choke
|Briley Skeet choke
|Briley Diffusion™ choke
On 12-yard birds, Skeet choke provides a 14% larger pattern; the Diffusion™ spreader tube, a 25% larger pattern. At 20 yards, the larger pattern bonuses remain pretty much the same -- about a 14% larger pattern with Skeet and a 31% larger pattern with the Diffusion™ spreader choke.
Write this down: You will take more birds with open chokes!
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