Old, but relevant:
http://www.ballisticproducts.com/bpi/articleindex/articles/312inch1/GA1235K1.html Good arrticle here: (From Eastern Woods and Waters) (Bold at end is mine)
Steel Shot Under The Microscope
Care is Called for With Loads, Chokes and Range
Shotgun shells loaded with non-toxic tungsten or bismuth are clearly more deadly that those loaded with steel-yet most waterfowl hunters continue to use steel, the lower cost being a factor. So does that mean we have to be out there risking crippled birds?
More differing opinions have been expressed, and more BS has been printed regarding the use of steel shot than just about anything else that I can think of.
To determine for myself the facts about shotgun shells loaded with steel, I conducted a series of pattern tests spread over two years. I determined that by selecting the proper load and choke combination, steel is more than adequate for almost all waterfowl hunting.
In these tests I used Beretta AL390, Browning Gold and Remington Model 11-87 semi-automatic 12-gauge shotguns, each chambered for 3-inch shells.
I also conducted tests using two 10-gauge Remington Model SP-10 shotguns, and two pump-action 12-gauge shotguns with fixed full chokes and chambered for 2 3/4-inch shells.
Most shotgun pattern testing is carried out at 40 yards-yet waterfowlers often shoot at decoying ducks at ranges of 15 to 35 yards, or do their pass shooting at 45 yards or more. To find out more about steel, 33 1/3 yards and 50 yards were selected as test ranges. For these tests the standard 30-inch in diameter circle was used to measure the pattern results. The shorter range 33 1/3 yard tests were soon dropped as all the 1 1/4 or 1 3/8 ounce loads tested proved more than adequate at that distance.
It's commonly accepted that to assure that a bird will be hit in a vital area, three to five pellets must hit the bird with sufficient energy so as to penetrate the vitals. So, how many pellets must we have in a 30-inch in diameter circle to meet this requirement?
The more pellets in the shotgun shell, the better the odds of three to five pellets hitting the bird. Thus, in my tests I used only 3-inch, 12-gauge loads containing 1 3/8 ounces of steel shot at a velocity of 1265 fps. Due to cost and time factors, complete tests were conducted only with loads of BB, No.1, No.2, and No.3 steel. Loads of steel BBBs were also tried, but are only presented for the Beretta AL390 and the 10-gauge Remington SP10. Other tests may indicate BBBs are the way to go, but that was not my conclusion. In testing I found the 1 3/8-ounce loads of BBBs lack sufficient pattern density at 50 yards with all 12-gauge guns tested. A minimum of five shells were fired with each gun, choke and shot size tested, and, if there appeared to be a wide variation in the count for those five, a further five were fired to ascertain the truth of the pattern. While manufacturers like to claim their steel shotgun shell loads are superior to the competition, in these tests shells from all three major manufactures were used, with no clear winner in terms of performance. Perhaps a more elaborate test would show differences.
Only the standard chokes that came with each shotgun were tested. The results are contained in the accompanying graphs.
Looking at the 50-yard, Beretta AL390 tests, we see that with steel BBs between Modified, (53 pellets) and Improved Modified and Full (57 pellets each) there is only a 4-pellet spread, indicating that larger steel pellets are not greatly affected by tighter chokes. The same applies to No. 1 steel. Yet in the chart it can be seen that the smaller diameter No. 2 steel pellets are more affected by the tighter chokes. In the case of No. 3 steel, the full choke is now too full, and results in a decline in pattern density.
Note also that at 50 yards the AL390 Improved Cylinder choke using No. 3 steel will put 92 pellets into the 30-inch circle. Does this work?
For several years our duck blind faced open water, across which, almost precisely 50 yards away, the open water gave way to cattails. Time after time blacks or mallards would fly along that dividing line between open water and cattails, and, time after time, would come down dead when hit with the 13/8 -ounce load of No. 3 steel fired from the improved cylinder choke of the Beretta AL390. Several years prior to these tests, back about 1994, using the then common recommendation of using larger steel shot sizes and more open choke, my hunting buddy and I both used modified chokes in our Remington 11-87s, and 13/8-ounce loads of No. 1 steel. Using this combination we would frequently knock birds down at 45 yards or more; yet almost half would hit the water wounded. The Remington 11-87 chart clearly indicates why this happened. At that point we were not too happy with steel, a common experience for those who use the wrong choke or steel shot load combination.
The charts for the Browning Gold and the Remington 11-87 speak for themselves. As can be seen, the Remington full choke is obviously too full for both No. 2 and No. 3 steel, leading to the belief that some manufactures are or were making chokes strictly based on the premise that most owners are primarily lead shot users. As can be seen in the charts, No. 2 steel is not a good choice for ducks in the Beretta except with a full choke, yet it's fine with a modified choke in the Remington 11-87.
As hunters, we should demand that the old choke designations such as improved cylinder and modified be discarded. Instead, each manufacturer should be required to stamp the internal dimensions of their barrel on each barrel manufactured, and the internal constriction on each and every choke sold. To this end I have included the internal dimensions of each and every barrel and choke tested. Only in this manner can certain conclusions be derived. A second AL390 also tested had identical barrel and choke dimensions to those listed, and gave similar results, as did a Beretta Model 686EL over/under with barrels that checked out at .722 inch. Chokes were within .001 of the AL390 chokes.
Two Remington pump action Model 870 shotguns chambered for the 12-gauge, 3-inch shell and equipped with interchangeable chokes, were also checked, Both had almost identical dimensions and similar pattern densities as compared to the Model 11-87s. Note that dimensions can vary .001 or more and that some Remington barrels checked out at .729 inch. This small variation has no significant impact on the final results obtained. Indeed, we should keep in mind that my measuring devices may not be totally precise.
In the case of the two Remington 10-gauge Model SP-10s tested, both the 26-inch barrel and the 30-inch barrel had identical internal dimensions. Based on the results as indicated in the graph, I suspect that an after-market choke with about .022 inches of constriction would be about right for the SP10, 10-gauge, and would give good duck killing patterns at 60 yards with No. 2s. At that range No. 2s still have 2.2 foot pounds of energy per pellet. Note also that at 60 yards, with the chokes tested, BB meets the 50-pellet minimum for Canada geese, and still has 5.5 foot pounds of energy (Fig.1) per pellet. Also tested were two older fixed full choked shotguns chambered for the 12-gauge 2 3/4 inch shell, a Remington Model 870 and Winchester Model 1200. With maximum 1 1/4-ounce loads of steel, the results were so close to one another that I have included only one graph that is valid for both. Hitting with the tighter pattern at the closer ranges may be the only negative. For the sea duck hunter who needs No. 2 shot, an older, somewhat beat up and rusty 12-gauge with a fixed full choke just might be the way to go.
I have not included tests with No. 4 steel, yet No. 4 steel is my preferred steel shot size along with a modified choke when hunting smaller ducks such as Ringnecks.
Before steel, my usual 12-gauge duck load for the season consisted of a 1 1/2-ounce load of No. 4 lead and a modified or full choke. Yet, on opening day, when the ducks were decoying close, we usually used improved cylinder chokes in our 12-gauges, and a 1 1/4-ounce load of lead 7 �s. This combination proved absolutely deadly out to 40 yards. On opening day of 1997 we used 12-gauge guns loaded with an 1�-ounce load of No. 6 steel, and improved cylinder chokes. Our shooting was held to 35 yards or less, and killed stone dead almost all the birds we shot at, including both mallards and blacks. Often, at the shorter ranges, wings were broken also.
Later that same week, when using this combination, I swung on a pintail but, by the time I had fired, the bird was at a full 41 yards (measured), yet came down dead. Out of curiosity, an autopsy in the blind revealed that many of the No. 6 steel pellets had barely made in through the heavy feathers, with several still visible, lodged in the flesh next to the skin. Yet the duck was dead, and an examination revealed several wounds to the head and neck. And that is the secret of No. 6 steel. The 1 1/4 ounce load sends out a sleet storm of steel containing 396 pellets, the result being that at 35 yards or less almost always several of these pellets will hit the vulnerable head and neck.
The foot pounds needed for each shot taken can vary widely. After considerable sifting through the data available and field data gathered first hand, I have concluded that two foot pounds is about right for mallards, and five foot pounds for Canada geese. Note that, at 50 yards, No. 3 steel at a rated velocity of 1265 feet per second meets the 2-foot pound requirement for ducks, and that BB meets the 5-foot pound requirement for geese. (Refer Fig. 1.) This chart is based on data supplied by the ammunition manufacturers plus that from other sources, and assumes that the foot pounds of energy decreases in a linear fashion.
As a hunter and writer, the late Don Zutz once wrote: "The older I get and the more birds I clean, the more I realize head/neck and wing-bone hits are the most important in bring down a bird. Pellets to the rear half of the body cavity will often leave birds to sail away to die in some brushy or swampy corner." I'm inclined to agree with Zutz, and, for that very reason take great care to set up blind and decoys in reference to wind direction so as to prevent the need to take tail end shots at departing waterfowl after the shooting starts. Having walked the 50 yards to the pattern board and back several hundred times, I have a good understanding that 50 yards is a very long distance to be shooting at waterfowl. I have carried a range finder, first the split image type, and then those using a laser, to the marshes for almost 30 years in order to measure actual shooting distances. Yet not one in 500 waterfowl hunters does this. Without a rangefinder, accurately ascertaining shooting distances is very iffy, with errors of 30 per cent or more very common. No. 3 steel at a velocity of no more that 1330 fps is my current and most often used duck load. I usually use an improved cylinder choke, but may switch to modified if the need arises. For geese, BB steel, and modified choke. For reduced recoil, use the 1 1/4-ounce steel shot loads at a velocity of 1330 fps or less.
With a 1 1/4-ounce load, the charts, at least in theory, are valid for 45 yards. I have no use for the 3 1/2 inch 12-gauge shell, having fired enough boxes of these to know there is no pleasure involved in pulling the trigger, and a whole bunch of negatives. Nor am I much enthused about the current rash of high velocity, low payload steel shot loads. At 35 yards or less they look impressive as the feathers fly and the bird staggers in the air, yet hunters are advised to test these loads at 50 yards before coming to any decision. My conclusion is that ammunition companies have found it's much cheaper to add a few grains of powder to a shotgun shell instead of an extra one-eighth ounce of steel shot! Hunting waterfowl and shooting a shotgun should be a pleasurable activity, not one where the shooter has to endure significant punishment. The current crop of 3 1/2 and 3-inch high velocity steel loads have levels of recoil that exceeds by a wide margin what a waterfowl hunter can tolerate without having their shooting skills deteriorate. Provided the right load and choke combination is selected, the limiting factor in 99 per cent of waterfowl hunting is not steel shot, but rather, the hunter, and his or her ability to point the shotgun accurately.
