Shot Talk

Worries Revisited

My column "Worries," in November/December 2007, offered a brief treatment of three issues of concern to many shotgunners. It was not intended to fully explore the technical details about any of the issues. However, two of the items require further discussion and clarification.
First is the worrisome issue of shooting longer-than-intended shells in short chambers. I discussed the effect of firing shells that exceed a gun's chamber length by 1/4" and longer. As part of that discussion, I stated: "From my testing, you can count on at least a 1,500-psi increase in 12 gauge for the first 1/4" of excess shell length." That is a mistake, and the mistake is mine. It should have read: "... at least a 150-psi increase... " And that which followed should have read "... a 400- to 500-psi pressure increase for firing certain 3" .410 loads in 2-1/2" chambers" (not 4,000 to 5,000 psi). I don't know how I missed that extra zero in both statements, but I did. I'm sorry for any heartburn this may have caused. Happily, the error was in the direction of safety.
Setting aside exactly how much pressure will increase when shooting long shells in short chambers (which varies by load, length differential and gauge), the fact is that longer shells often contain heavier loads, which often develop higher chamber pressures than the more modest loads generally assembled in shorter shells. This is what the gunmakers have to worry about. They do not have control over how much heavier the shot charge weight or how much higher the pressures may be in longer cartridges depending on how they were loaded. And even though they are fully aware of exceptions, they do not want to take the space in their owners' manuals or in the language they may stamp on their barrels to go into the myriad of exceptions that allow that sometimes longer shells fired in short chambers are perfectly OK from a chamber-pressure standpoint.

For example, certainly you can take a 3" 12-gauge shell and load it with a mere 1 oz of lead shot and generate chamber pressures of less than 7,000 psi; you can do the same with specific 2-3/4" 12-gauge loads. These low-pressure loads may increase the chamber pressure by only about 200 psi because of the effect of the extra 1/4" hull unfolding into the forcing cone of, respectively, a 2-3/4" or 2-1/2" chamber. But gun manufacturers can't count on all shooters limiting themselves to shooting only special low-pressure 3" shells in their 2-3/4" chambered guns or special low-pressure 2-3/4" shells in their 2-1/2" chambered guns. The manufacturers always have to worry about the possibly damaging effects of someone shooting the heaviest available 3" 12-gauge loads in 2-3/4" chambered guns or the heaviest 2-3/4" 12-gauge shells in 2-1/2" chambered guns. The same concern applies to all 3-1/2" 12-gauge loads stuffed into shorter chambers and to the same shell-length issues in other gauges.
And further, gun manufacturers have to worry not only that those long loads may contain lead shot but also that they might contain hard shot types such as steel or HEVI-Shot. They have to worry about the down-barrel pressures created by magnum loadings, which tend to use slower-burning propellants than lighter loads.
Shotgun manufacturers also have to worry about what happens to the choke area as the ever-accelerating ejecta (wad, shot and buffer, if any) slam into the choke constrictions. Things may be OK back there at the chamber, but the choke area of the barrel may not be able to handle the higher radial pressures caused by heavier magnum loads available in longer shells, especially those containing hard shot types. Also, certain chokes may not be able to handle the higher strain generated by the high- and ultra-high-velocity loadings currently popular.
As one writer on an online forum said, "It's all about liability." Yes, that is precisely what is at issue here, and it's a concern for liability that has legitimate safety at its core. Shotgun manufacturers bear liability if they do not warn precisely what the maximum-length shells should be for particular firearms if they know or should know that certain dangers could come into play.
I briefly addressed increased recoil from shooting longer shells in short chambers in November/December, but it's not the shells themselves or their possible higher pressures that can increase recoil. If the longer shell contains a heavier shot-charge weight and/or produces a faster launch velocity than is typical for the shorter shell, greater recoil will be generated. The issue is whether your gun-especially a lightweight double-is able to withstand high recoil forces without certain metal parts starting to break and wood cracking.
So I stand by what I wrote about longer shells in short chambers. They almost always raise pressures. Yes, longer shells can be selected purposely or custom loaded so that the pressure-raising effects of the longer hulls unfolding into the forcing cones are offset by lower pressures built into the shotshell loads themselves. There is at least one 2-3/4" 12-gauge lead load that the overseas manufacturer advertises as safe for use in 2-1/2" chambers. Fine. That manufacturer gets to bear all of the liability for consumers using its 2-3/4" shells in 2-1/2" guns. If that company feels comfortable with this, so be it. But it is not necessarily all right for other shotshell manufacturers, and I'd bet you could find several gunmakers that would not be happy with that position either.
A couple of courteous e-mails I received on the long shells/short chambers topic came from Parker shotgun owners. They pointed out that many Parkers were made with chambers 1/8" shorter than the 23/4" shotshells they were designed to fire. No problem. In my "Worries" column I did not discuss the effects of guns chambered only 1/8"-or even 1/16"-shorter than the shell. In my testing I never have found that a chamber/shell disparity of 1/8" or less created a chamber- pressure increase large enough to be of concern. This is with lead-shot loads.
The second area needing clarification is the discussion in that same column (Nov/Dec) concerning shooting US-manufactured shotshells in European-made shotguns. Here, too, more detail is needed. The issue is that often, but not always, US-made shells develop higher chamber pressures, carry pressures farther down barrels-especially magnum and harder-than-lead loadings-and create greater strain at the choke than many European-loaded shells. Therefore owners of foreign-made shotguns wishing to fire typical US-manufactured shotshells should make certain that the guns have been proof tested, hopefully according to current SAAMI voluntary standards, or that they are approved for use with current American factory shotshells or reloads that conform to SAAMI standards.
In that previous column I did not list specific European or other foreign-manufactured shotgun brands. I wanted to urge caution when buying older shotguns made overseas, especially those that are no longer manufactured or those that are imported by individuals or made for private labels. I did not mean to imply that major foreign-made shotguns specifically targeted at the US market-such as Benelli, Beretta, Browning, Franchi and Caesar Guerini-should be cautioned against. Consumers can assume that foreign-made guns that are extensively marketed here-especially if the makers have set up a US office-are perfectly OK for use with modern American shotshells. If they are not, the onus is on the manufacturers to make clear in their owners' manuals just which shotshells their guns are not safe with. Any time you don't know for certain, you should contact the manufacturer.
If the manufacturer that made your gun is still in business, contact the company and try to obtain clarification on your gun's proofing and a list or description of currently available shotshell loads with which the gun can be used safely. If the manufacturer is not in business or will not help with your quest for safe ammo, you could attempt to have the gun proof-tested to current SAAMI standards. (Editor's note: We know of at least one facility that can do this in the US. H.P. White Laboratory, Inc. [www.hpwhite.com; 410-838-6550] in Maryland will proof test shotguns for $420, though considering the risk of destroying a gun with loads generating in the neighborhood of 20,000 psi, the firm's chief engineer says he may try to convince you not to go through with it.
If you fail with the manufacturer and the gun is not proof-tested to SAAMI standards, accept the fact that you own a firearm for which there is no clear information concerning safe shotshell loads. The safest bet is to not fire it, but if you insist on shooting it-and the following is not a recommendation-gravitate toward very light, low-pressure, lead shotshell loads of a length no longer than that for which the gun is chambered. You assume all risk for firing any shotshell loads in any firearm for which clear information on safe ammunition is not available.
It is a very real worry when there is no manufacturer to contact any longer. What do you do then? If you want to believe some writer or Website poster who states or implies that certain loads should be fine without evidence of destructive or proof testing on your specific shotgun make and model, it's still pretty much a free world. But personally, I strongly advise against taking that risk. I think it's irresponsible to be posting and publishing messages that state or leave readers to assume that they shouldn't be concerned about this situation because the posters and/or their independent shotshell testers believe they have found evidence that negate the warnings issued by shotshell and/or gun manufacturers.
One last thought: I have testified in court as an expert witness in personal-injury cases on behalf of both shotgun owners and shotgun and shotshell manufacturers and have witnessed what can happen to a defendant when a child with blown-off fingers or a bystander with facial damage goes after the owner or shooter of the gun that caused the damage. Whenever the plaintiff can demonstrate that the gun was fired with cartridges not specifically designed for use in the gun, or that the gun or shotshell manufacturer's warnings were ignored, or when the gun was fired in a manner that deviated from normal and customary safe firearms practices, the gun's owner or shooter almost always loses.
So think about it. My advice on shotguns and shotshells: Always heed all current and customary manufacturers' cautions and warnings.

To correspond with Tom Roster or to order his third-edition reloading manual on buffered lead and bismuth shotshells, his new HEVI-Shot reloading manual, his 75-page manual on shotgun-barrel modifications or his instructional shooting videos, contact Tom Roster, 1190 Lynnewood Blvd., Klamath Falls, OR 97601; 541-884-2974; tomroster@charter.net.