While dated, lots of good info, most of which still applies! This article summarized results from firing approximately 500 patterns with Remington Express 12-ga. buffered buckshot loads, without shot wrapper from Model 870 pump shotguns. Firings were conducted by NRA Technical Staff, using test materials provided by Remington Arms Co. The article as published was oriented towards deer hunting, rather than home defense, for political reasons. Ten patterns each were fired at 25 and 40 yards, from cylinder bore, improved cylinder (1/4 choke), modified (1/2 choke) and full choked barrels. Cylinder and IC barrels were standard Police and Military Guard and Riot Gun barrels 20 inches long. Modified and full choked barrels were standard sporting barrels of 26" and 28", respectively. Experimental modified and full choked 20 inch police and military barrels were also tested, although the results with those were not included in the published article, because of the desire to maintain a "sporting" focus. Other than an slight, insignificant drop in velocity, results with the shorter, more tightly choked barrels was not materially different from common sporting-length barrels. The same Remington 870 Wingmaster action was fired repeatedly interchanging the four different barrels. Patterns were fired against a 48" square plate of AR500 steel 1cm thick, photographed and the oiled Titanium dioxide pigment rebrushed between shots. Pellet hits were plotted in relation to a clear plastic overlay having a 30" outer circle, positioned after each shot to to contain the greatest number of pellets, the clear patterning template having a 21.2" diameter inner circle, the 30" circle and 21.2 inner ring then being quartered by strung piano wires into eight equal-area fields. The 21.2" inner circle approximates the major torso area of a US Army "E" or FBI “Q” silhouette. Pellets striking inside the inner ring have a greater probability of striking vital organs, whereas those in the fringes outside the inner circle, but still within the 30" outer ring are more likely to cause non-life threatening wounds to the extremities. A 100% pattern in which all pellets strike within the 30" ring may be ineffective unless the inner circle of the pattern surrounding the aiming point contains three or more pellet hits. The combination of soft buckshot, unbuffered loads and tight chokes increases pellet deformation which results in "doughnut" shaped patterns having weak centers. WW2, Korean and Vietnam-era Army experience indicates that fewer than three pellet hits of 00 buckshot do not produce “instant incapacitation,” unless one or more of those pellets strike vital areas of the head, neck, or chest. With random distribution of as few as three pellets in the 21.2" circle, hitting a vital spot depends on luck and random variations of chance. More hits are better! A single 00 pellet (.33 inch diameter, weighing 60 grains) at 30 yards has a kinetic energy of about 120 ft.-lbs. Three pellet hits therefore produce 360 ft.-lbs., which approximates the kinetic energy of a single round of .45 cal. Ball ammunition fired from the M1911 service pistol. More than three pellet hits, when their combined effect is distributed over the body, produce greater shock to the nervous and vascular systems and vital organs struck than a single projectile hit having the same kinetic energy. For law enforcement and military purposes 4 or more hits is considered "adequate" performance, producing a high probability of instant incapacitation. Any shotgun-ammo combination reliably producing 5 hits with 00 buck at realistic combat ranges from 25 to 40 yards is said to provide "good" performance. More than 5 hits is considered "excellent." The standard Remington Express 9-pellet buffered load of 00 buck with no shot sleeve, fired from an 870 cylinder bore 20" riot gun averages 8.9 hits in the 30" circle and 7.1 in the 21.2" inner ring at 25 yards. This falls off to 7.5 and 3.3 hits at 40 yards. Repeating the test using a 20-inch improved cylinder barrel, all nine pellets strike in the 30" circle and 8.6 in the 21.2" inner ring at 25 yards. Repeating the test again, at 40 yards, the IC barrel produced 8.0 and 4.4 hits, respectively. For civilian home defense purposes the 20" improved cylinder "Brushmaster" or "Deer" barrels with rifle sights give dependable performance. For combat use the 12-pellet "short-magnum" load of 00 buck is a better choice in 2-3/4" chambered guns, if you can tolerate additional recoil. Even though the pattern percentages produced are lower, you can expect one additional pellet hit inside the inner ring. If you wish to maximize pellet count to optimize pattern density, while still having adequate penetration to defeat interior walls or auto glass, the 20-pellet "short magnum" load of No.1 buck is the best choice. No.1 buckshot weigh 40 grains each, producing 103 ft.-lbs. at the muzzle, 69 ft.-lbs. at 30 yards and 61-ft.-lbs. at 40 yards. It takes twice as many pellet hits with No.1 to produce the same kinetic energy as half as many 00, so 6 pellet hits are marginal, 8 hit "adequate" and ten or more "good" performance. No. 4 buck weigh only 20.7 grains each, and have 81 ft. lbs. of energy per pellet at the muzzle, 45 ft. lbs. at 30 yards and 41 ft. lbs. at 40 yards. Police and military experience has shown that despite excellent pattern density, No. 4 buck is inadequate to reach vital organs if major bones are hit, such as a sternum, rib or defensively positioned arm. The military M257 buckshot cartridge with 27 pellets of No.4 is specified only for interior guard and corrections use where collateral damage to bystanders must be minimized. As a general rule, soft lead, unbuffered buckshot spread about 1 inch per 1 yard of distance beyond the muzzle, when fired from a short-barreled cylinder bore police riot gun. Hardened shot assembled in modern buffered loads containing granulated polyethylene “grex” do better. Typical 15-yard patterns on a military silhouette using the Federal Pattern Control 00 buck from a 20" ¼ choke or Improved Cylinder barrel are about 8" in diameter.