I couldn't find a whole lot of data online about the effectiveness of rifled chokes, except for all the geniuses out there guessing that "a couple inches of rifling won't do anything". Being that 1 7/8 inches of rifling in a snub nosed revolver stabilizes a 38 special, I thought I'd give this a try.
I went to an indoor 75-yard range with my Benelli M2, fitted with a standard IC choke, and I also brought a Carlson's rifled choke tube I got from choketube.com. I was bench rested and heavily clothed with a leather recoil pad for what would be a punishing 38 slugs to the shoulder.
First up, 2 3/4 Federal Truball slugs. Smooth, they formed a 3-round, 3" group. With the rifled choke, same thing, 3". However, in this case, two of the shots hit the bullseye where the smooth group was patterned high and right.
Second, Winchester 2 3/4 Super X. Smooth, 4" group. Rifled, 5" group. However, again, two shots were on bullseye with one 5" flyer on the rifled group.
Since my other reason for going was to prepare for an upcoming pig hunt, I tried two types of slugs better suited for thick-skinned game:
Winchester 2 3/4 Razorback. Both the smooth and the rifled choke gave me a 4" group. In this case, neither looked like the better group.
Brenneke Black Magic 3" slugs. Smooth, formed a 4" group well off target. Rifled, it formed a very nice 2.5" group just off bullseye. I later put up another target and put another 2 rounds within 1.5 inches of each other.
I also tried a few of these slugs through a fully rifled barrel. The truballs did marginally worse than they did through the smooth bore. The Brenneke's keyholed!
So, to sum it up, I'd say that a rifled choke has very little effect on a foster slug, though if anything, it does help slightly. A Brenneke slug, however, is affected pretty dramatically. Unlike Fosters, the Brenneke slugs are made for smooth AND rifled barrels. Smooth, they are okay, maybe not even quite as accurate as a foster. Rifle choked, they tighten up considerably better than a foster, and fully rifled, they have sabot-like accuracy, though with less reach because of their relatively low velocity and poor ballistic coefficient.
A couple inches of rifling IS beneficial, so long as the slug can grip it. Seems the Brennekes can and the fosters barely can.
Oh, and Truball slugs are considerably more accurate from a smoothbore than these other slugs.
I went to an indoor 75-yard range with my Benelli M2, fitted with a standard IC choke, and I also brought a Carlson's rifled choke tube I got from choketube.com. I was bench rested and heavily clothed with a leather recoil pad for what would be a punishing 38 slugs to the shoulder.
First up, 2 3/4 Federal Truball slugs. Smooth, they formed a 3-round, 3" group. With the rifled choke, same thing, 3". However, in this case, two of the shots hit the bullseye where the smooth group was patterned high and right.
Second, Winchester 2 3/4 Super X. Smooth, 4" group. Rifled, 5" group. However, again, two shots were on bullseye with one 5" flyer on the rifled group.
Since my other reason for going was to prepare for an upcoming pig hunt, I tried two types of slugs better suited for thick-skinned game:
Winchester 2 3/4 Razorback. Both the smooth and the rifled choke gave me a 4" group. In this case, neither looked like the better group.
Brenneke Black Magic 3" slugs. Smooth, formed a 4" group well off target. Rifled, it formed a very nice 2.5" group just off bullseye. I later put up another target and put another 2 rounds within 1.5 inches of each other.
I also tried a few of these slugs through a fully rifled barrel. The truballs did marginally worse than they did through the smooth bore. The Brenneke's keyholed!
So, to sum it up, I'd say that a rifled choke has very little effect on a foster slug, though if anything, it does help slightly. A Brenneke slug, however, is affected pretty dramatically. Unlike Fosters, the Brenneke slugs are made for smooth AND rifled barrels. Smooth, they are okay, maybe not even quite as accurate as a foster. Rifle choked, they tighten up considerably better than a foster, and fully rifled, they have sabot-like accuracy, though with less reach because of their relatively low velocity and poor ballistic coefficient.
A couple inches of rifling IS beneficial, so long as the slug can grip it. Seems the Brennekes can and the fosters barely can.
Oh, and Truball slugs are considerably more accurate from a smoothbore than these other slugs.