.38 S&W is prudent gunsmith’s choice to restore antique rook rifles.
A condensation of Ed Harris article from The Fouling Shot - cross-posted by permission:
The attraction of the British "Rook Rifle" concept is that medium-bore cartridges, similar to black powder revolver cartridges, when fired from a rifle, are quiet. They make little more noise than standard velocity .22 LR, but they hit harder than a .22, making them more useful for dispatching larger small game animals or farm varmints such as coyotes or groundhogs.
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The small powder capacity of the similar .38 S&W cartridge is an advantage for this purpose. Powder positioning is not an issue affecting ballistic uniformity, which it can be in the longer .38 Special case. New .38 S&W brass and factory ammunition are readily available. No factory +P or jacketed loads are produced in this caliber, so the .38 S&W is the prudent gunsmith’s choice to safely restore black powder action rook rifles to service. It is also historically appropriate, because it dates from the same era as the long-obsolete .380 Rook and .360 No. 5 British rook rifle rounds we would use it to replace.
There is a very modest velocity gain when the .38 S&W cartridge is fired from a rifle, but its potential for producing a supersonic, “cracking loud” report is very limited. This is because the expansion ratio of a longer rifle barrel exceeds the limitations of its tiny powder charge for adiabatic expansion. The result is that standard-pressure, smokeless .38 S&W revolver loads, at less than 14,000 psi, using fast-burning powders like Bullseye, produce ballistics from a rifle very much like the .38 Special fired from a 6-inch target revolver. I say, that is just right for "rural-agricultural" and "suburban pot shooting."
A wide-flat-nose or wadcutter at subsonic velocity performs on of proportion to its kinetic energy. A .38 Special wadcutter deposits about the same energy into a 20cm gelatin block before exiting that .45 ACP hardball does. Modern .38 S&W hand loads assembled with large meplat 190-grain cast bullets with about 2 grains of Bullseye or TiteGroup do likewise. No expansion occurs at these velocities, but the straight-through penetration is simply astounding. In the 1880s the .380 Rook and .360 No. 5 were used for culling "park deer" and if pressed to shooting coyotes and such the .38 beats any .22 rimfire in spades!
I had no interest in trying to see how "powerful" a load I can assemble for my .38 S&W Rook Rifle. I have a .357 rifle which scratches that itch. The objective from the beginning was to enjoy a mild, small capacity cartridge producing ballistics almost like a large-caliber air rifle, exploiting a heavy, blunt, slow bullet, ideally "silent without suppressor" at 600-700 fps and under NO cirsumstances over 900 fps, which would produce low noise, while being hard hitting, equal to full-charge .38 Special from a 6-inch revolver and accurate out to 50 yards.
In particular, I wanted to explore the possibility of using as heavy a bullet as could be launched at the lowest velocity which would reliably exit the barrel, which we found to be about 600 fps with soft lead, 190-grain FN bullet from the rifle and 500 fps from a 5" S&W Victory revolver.
A 1:10" twist 9mm barrel ensures adequate gyroscopic stability with 190-gr. bullets at <700 fps.
In previous extensive testing of a .38 Special barrel to fit this action, having a 1:20" twist, I found it very accurate with standard pressure as well as +P 110-158-grain revolver loads. Heavier bullets over 180-grains had to be driven about 1050 +/- 30 fps to be accurate and stable, resulting in a LOUDER gun, which I DIDN'T want, if the obective was to dispatch both small furry and hooved edible critters in the garden, without disturbing the neighbors.
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The “object of my desire” was a handy, short rifle, less than 36” long, less than 5 pounds. The result is both stealthy-quiet and "hard-enough" hitting. John Taylor turned down and fitted a Green Mountain "Gunsmith Special" 9mm barrel and chambered it with a Manson .38 S&W "Rook Rifle" reamer having a 3 degrees Basic forcing cone of .363" major diameter at the case mouth. It engraves the noses of either the 36-187H or 36-190T Accurate bullets upon chambering, just like Eley Tenex chambered a Winchester 52.
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While it is true that firing a heavy, "fat" .362 lead bullet raises pressure a bit when being squeezed down into a 9mm barrel, the resultant pressure-rise is well within the design limits of our “Infamous Bunny Gun.”
Other barrels I have for it chambered in .38 Special +P and .45 ACP operate nicely at 20,000 psi or so. Testing of .38 S&W heavy-bullet loads has substantiated that normal revolver loads squirting soft lead .38 S&W slugs down a 9mm barrel are mild, extract easily and are accurate. The Manson .38 S&W Rook Rifle reamer provides a gradual forcing cone into the origin of rifling, and has proven highly satisfactory with both factory .38 S&W ammo and standard-pressure, heavy-bullet handloads. Fired cases are lightly smoked, primers are round, and a clean burn indicates efficient use of the tiny 2-grain powder charge. Charges which have proven safe and accurate in the rook rifle, S&W Victory Model and S&W Model 32-1 Terrier are 2 grains of TiteGroup or Bullseye with either Accurate 36-187H or 190T bullets or 2.5 grains of Bullseye, WST, or 452AA with the 36-151H, 36-155D or 36-159H.
Factory .38 S&W 146-grain LRN gives 850-900 fps in a 20-inch rifle vs. 650-700 in a 5" revolver.
My "Lettuce Protector" was built on a pre-war H&R .44/12mm shotgun frame. These are a simple rebounding-hammer break-open design, without transfer bar, made from the 1890s until just before WW2. Before 1900 these guns were chambered for the .44 Game Getter (.44-40) shot cartridge. Guns produced after WW1 are marked either .44/12mm or .44/.410, being chambered for the Eley Two-Inch cartridge. It is common for these old guns to be found, having been rechambered for American 2-1/2" or 3" shells.
My Bunny Gun pictured is 34-1/2 inches long and weighs 4-1/2 pounds. I have found it best to utilize an "optimum trajectory" in which the maximum bullet rise over its 100 yard useful trajectory does not exceed about 3 inches. I take a 6:00 hold on a typical small game animal until the front sight bead about covers the critter, and then if it does, I just blot him out and shoot.
With the .38 S&W cartridge this works out to a 75 yard zero and a 90-yard "point blank" range, at which the path of the trajectory drops about 3" below line of sight. The maximum useful range where rifle velocity decays to about the same level as a revolver near the muzzle is 150 yards, with 36 inches of drop, about the height of an Army E silhouette if you must discourage or repel marauding, Wild Indians, Sasquatch, or Zombies invading your garden vegetable patch. Please don't shoot The Moth Man, as latest intel here says he's really a CIA Black op, but is supposed to be "friendly."
Ten-shot groups with .38 S&W factory loads and simple open sights average 3" at 50 yards, and 6" at 100 yards. This is about the same as I do with an open-sighted lever-action cowboy rifle firing .38 Specials. Entirely adequate for making "gong music" on the steel targets and scaring Mr.Wabbit.
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The lightest charge I can measure, 1.7 grs. of Bullseye using RCBS Little Dandy Rotor #00, with Accurate 36-190T exits the 20 inch barrel every time, at 600 fps, and from the 5" S&W Victory at 500. They are quiet enough to shoot without ear protection and hit 3" below the front sight at 50 yards, making 3" ten-shot groups. Raising the open sight elevator to the second elevator step centers the group at 50 yards. Using the third step and blotting out the 12" gong at 100 yards I ran ten straight hits, and again on the full sized “E” silhouette framing the shoulders with the front sight. The slow bullets whacking the steel targets make more noise than the gun going off!
For those wanting to build their own "American Rook Rifle" which can also use factory loads and for which a companion revolver is affordable and readily available, the .38 S&W cartridge represents absolute “Cat Sneeze Perfection!”
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