Ammunition shelf life; aged ammo seldom produces dangerous situations...only disappointment.
Such famous and respected craftsmen as Dale Goens, Jerry Fisher, Al Lind (stockmaking) and Tommy Kaye (engraving) served as instructors, which meant that I felt I was running in pretty fancy company! Trinidad is, of course, the institution whose gunsmithing program was originally organized by none other than the old master himself, P.O. Ackley. The school remains preeminent today as a source of professional gunsmithing training.
My students in the seminar were from many parts of the United States and Canada, and they represented a wide range of interests and experience. One, a Navajo game warden, was one of the best pistol shots I ever saw in action. Another was a serious handgun metallic silhouette shooter--from Montreal of all places (Canadian handgun laws being what they are). I learned a few things from my students, too, in return for whatever they may have learned from me.
I plan to instruct a similar five-day ballistics and handloading seminar at Trinidad next summer, pitched at the advanced level with a great deal of emphasis on practical, hands-on loading, shooting and testing. Prices charged for these courses are reasonable and include room and meals, and the Colorado high country is certainly a pleasant place to spend a few days in June or July. For more information, write to Dr. James Moseley, Trinidad State Junior College, Dept. GA, 600 Prospect, Trinidad, CO 81082.
One of the questions asked by a student in my seminar last week comes up from time to time in my reader mail as well. It concerns the shelf-life of ammunition in general and of handloads in particular. I happened to have with me a box of light target loads for the .357 Magnum, which my records reveal were actually assembled in 1967. The load is the common one of 3.5 grains of Bullseye behind a Lyman plain-based cast bullet #357477 (147 grains in Linotype from my mould), in magnum brass and with standard CCI primers. I believe the lubricant used was a homemade formula of beeswax softened with a little Vaseline.
Since we had access to the superb Ransom pistol rest and Oehler Model 33 Chronotach at Trinidad, we tested this ammo for both grouping and velocity, using a Smith & Wesson N-frame revolver. It easily gave 25-yard, 10-ring groups, clocking speeds of 855 feet per second (fps). The extreme spread over 10 shots was only 40 fps, with a standard deviation of 17 fps. Both figures are outstanding. The last time cartridges from that lot had been chronographed, 18 years ago, was from a 4-5/8-inch barrel on a three-screw flattop Ruger Blackhawk. The average muzzle velocity then was 775 fps. Our S&W at Trinidad sported a 6-inch tube, indicating a reasonable average velocity reduction of 49 fps per inch of barrel.
In short, these handloads performed within completely normal parameters and gave competition-grade accuracy after having been loaded nearly 20 years ago!
This may not be a universal experience. A former armorer for many years for the Army Marksmanship Unit (AMU) at Ft. Benning (now an instructor at Trinidad, who audited my seminar) commented that the AMU found that in custom handloaded .300 Winchester Magnum ammo, after even a few days, the bullet pull might vary from 200 pounds down to almost nothing. Such a variation is, of course, significant in precision, 1,000-yard shooting and requires that the ammo be loaded on the same day it is fired. This represents the shortest shelf-life I've ever heard of, although, of course, it did not produce a hazardous condition and might go unnoticed at big-game hunting ranges. Neither the cause nor a cure could ever be isolated, despite much research. My guess would be that the extremely short neck on this case was a contributing factor, at least.
Jacketed bullets in old loads occasionally seem to become set in case necks, almost as though cemented in place. If you adjust a bullet-seating die to reseat bullets in such rounds a few thousandths of an inch deeper, you can hear the bond break with an audible snap. Chronograph readings on such reseated bullets are usually much more uniform than on rounds from the same lot which have not been reseated.
On the other hand, I've pulled hundreds of bullets, using an inertial puller, from old military cartridges, some dating back to World War II, with no sign whatsoever of bonding. In no case have I ever seen bonding which seemed to offer danger in firing.
Modern smokeless gunpowder, especially the ball types, has an extremely long shelf-life, and the effect of age (provided the powder has not actually begun chemical deterioration) is, in my experience, always in the direction of a slowing down of the burning rate. Thus, pressures and velocities are always lower than normal.
I have seen very old primers give erratic results, and I suspect that this is the component most subject to deterioration with age. The fact that 30 to 40-year-old ammo may give a high percentage of misfires is most likely the fault of the primers. All of us have seen old factory or military cartridges with tension-fatigue splits in the case necks.
All components of a cartridge, therefore, are subject to aging. For the purposes of the handloader, however, shelf-life is indefinite, at least up to about 20 years. In no case which has come to my attention in the 30-plus years I've been pumping press handles has aging of ammunition created a dangerous situation. Usually, changes with age merely produce disappointment in the form of substandard velocities or failures to fire at all.
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|Publication:||Guns & Ammo|
|Date:||Oct 1, 1985|
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