120 duPont IM.R. No. 17yi. This powder is comparable in its range of usefulness, to I.M.R. No. 3031 but, being an early nitro-ccilulosc powder, its tolerance is narrower than that of No. 3031. ijl£ is difficult to ignite but is an excellent powder when ignited properly. It has been used with gas-check, bullets with a fair degree of success but its normal burning pressure is too high for such bullets and its proper use is in full loads with jacketed bullets. The means that metallic tin is incorporated in this powder. duPont IM.R. No. IS1/*. This is another "tin" powder, comparable to the new I.M.R. 4064 in its range of usefulness. It was brought out particularly for cartridges of small bore and large powder capacity such as the Newton and Magnum cartridges and is not as efficient as its newer counterpart in the military range of cartridges. Like 17V2» it is hard to ignite but sadsfactory if ignited properly and used in full charges with jacketed bullets, in the limited range of cartridges for which it was made. No more of this powder will be manufactured.
duPont I.M.R. No. 1147. This is another of the single base or straight nitrocellulose powders. I.M.R. No. 1147 was made especially for the Cal. .30-06 cartridge using the 173 grain boat-tail bullet and it was a good powder as far as long range accuracy was concerned. The well known and jusdy famous 1925 National Match ammunition was loaded with this powder and that statement would be a tribute to any powder. 1147 is a fine grained powder and flows nicely through mechanical powder measures but, paradoxical as it may seem, the use of this powder was abandoned by the government because it would not measure through the loading machines with sufficient accuracy. The specifications for the Government ammunition call for a definite muzzle velocity within an equally definite limit of pressure. I.M.R. No. 1147 would develop the muzzle velocity alright but the pressures were so close to the permissible limit that even the little variations in loading it mechanically were enough to put them over the line. When we are 121 reloading ammunition and get evidence of high pressure, we correct it by reducing the powder charge a litde. In other words, we change the specifications of the ammunition to suit the powder. But you can't do that with military ammunition; the specifications stay fixed and if a powder doesn't meet them, the powder is changed and that is what happened to this otherwise excellent powder.
No. 1147, in comparison with the new range of duPont powders, occupies the position of, and has about the same application as, I.M.R. Powder No. 4320. While No. 1147 is now obsolete, powder tables are available for it.
I.M.R. Powders numbers 1204, 17%, 1554 and 1147 are all progressive burning powders and as their manufacture has only recently been discontinued all available stocks should be fresh and in good condition. Tables of charges are available for all of them, and while those reloaders who have their charges all established and who have been getting good results with them will want, quite naturally, to stick with them as long as they are obtainable, the beginner is urged to use the newer I.M.R., or other powders in their place. The po%vders given in the foregoing table arc easier to ignite, burn more uniformly and will give better all-around results for reloading purposes.
I.M.R. No. 1185. This is a powder made especially for the Government for loading the Cal. .30 Model 1906 Mi cartridge with the 173 grain boat-tail bullet, for military usage. It is not obtainable commercially and can only be bought by members of the National Rifle Association, through the Director of Civilian Marksmanship. No more of it is being manufactured and no more will be obtainable when present stocks are exhausted. I.M.R. 1185 can, probably, be used in some other cartridges than the Cal. .30-06 but no such loading data is available for it. It is not suitable for reduced loads and its use is best confined to the Cal. .30-06 cartridge, using the 173 grain boat-tail service bullet with the proper weight of charge. Frankford Arsenal furnishes proper loading data for the .30-06 Mi cartridge.
Pyro Cal. .30 d. g. This was the first successful 122 military powder developed for the Cal. .30, Model 1906 cartridge, which used a 150 grain, flat base, jacketed bullet. It is a plain burning military smokeless powder and was for many years the only military rifle powder used by the United States. Its name indicates its composition, the "Pyro" standing for pyro-cellulose, which is a nitro-cotton of low nitrogen content—(12.6%). The "Cal. .30", indicates the caliber it was made for and the "d'\ that diphenylamine was used as a stabilizer. The "g" indicates that the powder contains graphite. This powder was also sold commercially for reloading purposes and could be used in a variety of cartridges. The commercial powders were known as duPont No. 20, and Hercules No. 308 powders. The Pyro Powders had a rather narrow tolerance and could not and should not be used for reduced loads, nor with cast bullets.
Pyro Cal. .30 d.g., was used in loading all war-time ammunition in .30-06 caliber up until the completion of the Government war contracts. Much of this powder was of poor quality because of hasty manufacture and the inability to get ingredients of the proper degree of purity and a lot of it, as well as ammunition loaded with it, has gone bad in storage. But it was by no means all bad and there is still some of it around that is in serviceable condition. Any of this powder that may have been purchased from the Director of Civilian Marksmanship within a reasonable period of time may be relied upon and can be loaded according to the data furnished by the shipping arsenal.
If the powder has been obtained from unknown sources or has been on hand for a considerable length of time, the reloader is advised to reduce his charges at least 5% from the standard, or better still, not to use the powder at all. This also applies to old canisters of duPont No. 20 and Hercules No. 308 powders. More or less of the volatiles will have evaporated from this powder» if it is old, creating a corresponding increase in ballistics. This will cause irregular burning and more rapid burning than normal 123 and, if old powder is used in heavy charges, dangerous pressures are likely to resulL There is no sense in fooling around with odd lots and old "clucks" of powders when fresh stocks of modern, progressive powders are readily available. The purchase of such lots of Government powder as may be offered for sale from time to time is only justifiable if you are content to load it in the cartridge it was made for and exacdy according to the loading data furnished with it. On the other hand, if you want a powder for general reloading purposes, and especially in other than U. S. Military cartridges, get a powder that is made for the purpose and on which adequate loading information is available. The few cents a pound that you save on the Government powder is no economy if you can't use the powder after you get it, and it costs just as much to ship one kind of powder as another.
Shotgun Powders. The ballistic requirements of powders for shotguns are entirely different from those for rifled arms. It is important that when a shot charge leaves the muzzle of the gun there should be relatively little pressure behind it, for if the muzzle pressure be too great, blown patterns will result. A blown pattern is caused by the filler wads driving through the shot charge, scattering the shot laterally and causing a pattern in the form of a ring of scattered shot with few or no shot in the center. To prevent this condition, quick burning powders are necessary and to make these powders burn fast, potassium or barium nitrate are sometimes incorporated in them. Shotgun powders are of two general classes; bulk powders and dense powders. The latter are manufactured in much the same manner as rifle and pistol powders and are usually cut into thin flakes or discs to increase their rate of burning. The bulk powders are made by a precipitation process and the grains take the form of small irregularly shaped lumps, porous and soft in nature and gelatinized only on their surfaces. Most of the dense shotgun powders are absolutely unsuited for use in rifle or pistol cartridges. Even 124 in reduced loads, they will give relatively high pressures for the low velocities they develop.
The bulk powders, of which there are two manufactured in the United States, are known as duPont Shotgun Smokeless and Hercules E. C. These powders can not be recommended for use in rifled arms but they can be used in reduced loads in some cartridges with good results. Due to their rapid burning and porous nature, they will develop dangerous pressures if overloaded and as no loading data is regularly available for using them in rifled arms, their use for such purposes should be avoided. The mere fact that a powder can be used is no excuse for using it, when safer and more efficient powders arc available.
Blank Cartridge Powder. This is a type of powder made especially for blank cartridges. It is extremely fast burning and develops high pressures even in blank cartridges. Loaded behind a bullet, it will almost surely burst any ordinary arm. This powder is not available to reloaders but in spite of this some of it turns up once in a blue moon. If, by any remote chance any of it comcs into your possession, destroy it at once. It is not only highly dangerous, but absolutely worthless for reloading purposes. Do not take any chances with it.
Sometimes old cans of powder will turn up and come into one's possession, usually as a gift from someone who used to reload ammunition years before. Such powder may be in good condition but the chances are against it, even though it appears to perform satisfactorily. There is no reason why it should not be used, but it is best to use it in reduced loads for short range shooting. I have some old Laflin & Rand powders that are still very good but I have some others that arc not. The double base or nitro glycerine powders will keep better and longer than nitro cellulose or single base powders and one should be especially careful when using old lots of the latter type.
Up until about a year ago, powder could only be shipped by freight. There were very severe restrictions and regulations on the way the powder had to be packed and the freight car it went into had to be labeled that it had w explosives in it, etc^ etc. The freight rate was one and a half times the first class rate and it was necessary to pay freight on one hundred pounds, even though the shipment only consisted of one lousy little canister of powder. Naturally, the freight charges were gready in excess of the value of the powder, when shipped in small quantities, and it was a pretty tough and expensive joh for a reloader to get powder. Thanks largely, and possibly entirely, to Bcld-ing & Mull, the Interstate Commerce Commission was finally convinced that smokeless powder was not as dangerous to transport as had been believed, and the shipping regulations have now been changed. SMOKELESS AND SEMI-SMOKELESS powders may now be shipped by express, at regular rates, the only restriction being that not more than ten canisters, containing not more than one pound of powder each, can be shipped in one case. BLACK POWDER MUST STILL BE SHIPPED BY FREIGHT. The change in regulations on the shipment of smokeless powder now makes it possible for the handloader to get about any kind of smokeless he wants, at a reasonable shipping cost.
It is advisable for the reloader to purchase his powder as close to home as he can so as to save as much as possible on the shipping charges. E. I. duPont de Nemours & Co., and The Hercules Powder Co., both of Wilmington, Delaware, are the only two manufacturers of smokeless powders in the country. They also manufacture black powder. Both companies have distributing points in various parts of the country, so by writing them, one can determine the most convenient point from which to order powder. Most, if not all, of the reloading tool manufacturers also carry stocks of powder. The Lyman Gun Sight Corp.,
126 endeavors to maintain an up-to-date list of dealers throughout the country who carry stocks of powders and cater to the needs of the handloader and it is entirely possible that other manufacturers of loading tools do likewise. The reader will do well, when in need of powder, to communicate with one or all of the firms mentioned, but first (and this may sound silly) inquire of your local sporting goods dealers, if any. I have on many occasions received requests for sources of supply for powders from localities where powder was readily available.
Semi-smokeless powder can be obtained from the King Powder Co., King's Mills, Ohio. As far as I know, this firm has no other distributing point but some dealers carry semi-smokeless in stock. In writing for sources of supply, be sure to give the name of the nearest large city, if you live in a small community, as dealers in small towns seldom find it worth while to carry powder in stock or to handle it at all.
The saltpeter, sulphur and charcoal from which black powder is made are all capable of absorbing considerable quantities of atmospheric moisture and combining them into powder docs not reduce their absorbent qualities. The graphite with which black powder grains are often coated helps to exclude moisture but does not absolutely prevent its absorption. Black powder is completely ruined by water and even though it only becomes damp, it will not regain its original strength when it dries out. Moisture causcs some of the saltpeter to dissolve and this saltpeter crystallizes out when the powder dries, destroying the original intimate mixture of the ingredients. The old adage, "keep your powder dry," is well applied to the storage of black powder. It must be kept dry, but the temperature under which it is stored is not important, so long as it does not approach the combustion point of the powder, of course. This point is way above the temperature of the hottest attic in summer so it is safe to say that the handloader can keep his black
127 powder in any dry placc away from fire. Black powder is a mechanical mixture and contains no solvents or volatiles that affect its burning rate.
Smokeless powder presents a set of conditions almost the reverse of those affecting the storage of black powder. In the first placc, smokeless powder is not affected by moisture. Of coursc it can not be fired when wet, but wetting it and drying it out does not affect its ballistic properties. In fact, one of the best ways to store smokeless powder for long periods of time is to immerse it in water. This method of storing powder is fairly new and was discovered quite by accident. A sunken French batde ship was raised after many years, during which the magazines had been full of salt water. Powder from these magazines, when dried out and tested, was found to give practically the same ballistics as when the powder was made many years before. This instance has led to the under-water storage of military powders, the use of which may not be required for years.
It has already been pointed out that in making smokeless powders, all of the solvents and volatiles can not be recovered from them and that the percentage of volatiles in them has a direct bearing upon the performance of the powder. Heat will drive these volatiles out rapidly, leaving the grains porous and gready accelerating the rate of burning. Storage under water keeps the temperature of the powder down and prevents it from drying out. Where powder must be kept in readiness for instant use, underwater storage is out of the question. Ordinarily, such powder is kept in hermetically sealed containers which arc stored in easily accessible magazines. These magazines arc well ventilated and sometimes are provided with means for keeping the temperature at an even level. 70° F. is considered about ideal and most ballistic tests are made with the powder at this temperature, but smokeless powder will stand very low temperatures. It will not remain stable at high temperatures and the reloader should keep his smokeless powders where the temperature never exceeds 90° F.; preferably, but not necessarily, in a dry place. The choice between a hot dry attic and a damp cool cellar should be the damp cellar for smokeless powder, and the hot attic for black powder. If the powder must be kept in a damp place, small gaskets of cork or rubber should be made for the canistcrs and the lids screwed firmly down against them.
But after all, why worry about hot attics or damp ccllars? Our American powders are remarkably stabie and if kept in a room where the temperature is livable they will keep almost indefinitely.
The powder companies' tables can be used to verify charges obtained from other sources, just as the spelling of a word may be verified from a dictionary. The usefulness of these tables is by no means limited to the simple procedure of picking a charge out from among those listed. As most of these tables give more than one charge for each weight of bullet for each caliber, and the difference between such loads is represented only by the difference in the weights of powder chargcs, a fairly accurate charge and velocity curve can be plotted from them. To do this, the vertical edge of a sheet of cross-section paper is marked ofif in increments of velocity in feet per second, within the limits of the loads in the table; then the horizontal side of the squares in increments of weights of charge, also within the limits of charges shown in the table. Dots can then be placed on the intersections of the horizontal and vertical lines, represendng the charge and velocity for each load, and connected by straight lines. If only two points are used, the "curve" will be a straight line and more than two points will give an angular line but this can be smoothed out into a regular curve beginning at the lowest point and terminating at the highest one, passing through any intermediate points. One can then read off the velocity of any charge of that powder for the cartridge and bullet it pertains to and the velocity figure obtained in this way will be quite accurate. It is useless to do this with loads taken from several different tables; they must all be from the same table and for the same caliber of cartridge and weight of bullet, if only the bullet weight is given, or for the same make, weight and kind of bullet if possible. Every condition must be exacdy the same, except the weights of the charges.
130 Extending the curve beyond the plotted points will not give accurate results and it is of little use to do this, as the highest charge given in the table is probably the heaviest one that should be loaded anyway.
This can also be done with pressures, making the curve a charge and pressure one, but there is absolutely no reason for making such a curve. As long as the pressure is safe, who cares what it is? IF A CHARGE AND PRESSURE CURVE IS PLOTTED FROM A POWDER TABLE, UNDER NO CIRCUMSTANCES SHOULD THE CURVE BE EXTENDED BEYOND THE HIGHEST CHARGE POINT. NO ONE CAN PREDICT WHAT WILL HAPPEN BEYOND THIS POINT. The heaviest loads in the tables should only be used with the greatest care and with new cases. Even new cases are not infallible, for once in a while they will give way near the heads because of some hidden defect that could not be seen by the inspectors. The illustration on Plate XVI shows two failures of this kind that occurred with normal factory loaded ammunition. Both were fired in bolt action rifles and both resulted in eye burns from the gas escaping back through the bolts. If you must load the heaviest permissible charges into your cartridges, by all means use new cases and answer the following questions to yourself before going ahead with the loading.
1. Are my bullets of the same diameter, weight and hardness as those used in establishing the load?
2. Arc the bore and groove dimensions and the throating of my gun the same as those of the test gun?
3. Do I know the correct depth to which the bullets should be seated?
4. Arc my cases of the same inside shape and the same j^i capacity as those used in developing the load?
5. Arc the vents of my cases the same diameter as those of the cases with which the load was developed?
6. Are my primers correct for the vent size of my cases and will they give the same order of ignition as those used by the powder manufacturer?
7. Is the chambering of my barrel the same as that of the test barrel and especially, is it the same diameter at the ncck?
8. Is my gun brecchcd up properly and in safe condition to use with heavy loads?
If you can answer all of those questions in the affirmative you can, by careful loading, duplicate the ballistics of the load in the table of charges. I might even say that if you can answer all of those questions in the aJfirmative, you are a magician. The sole point in listing them is to show that duplicating the results shown in a table of charges takes a lot more than just using the same kind of a bullet and being careful with the weights of the powder charges. It is best to keep the weights of charges just a little less than those shown in the tables when the heaviest loads are used, for a litde shading in the charge will not cause much loss of velocity but it will ease up the pressures and allow for the variables in components that the reloader has no means of detecting.
Variations in Components.
The variations in components that will cause increases in pressure may be summarized as follows:
t. Enlarged vent in the cartridge case permitting more of the primer flash to reach the charge thereby increasing the initial rate of burning. This will also increase the back thrust of the primer itself, due to higher pressure than normal within the primer pocket.
2. The use of a hotter primer than the vent is designed for will also increase the initial rate of burning of the charge.
3. The use of too much of the right kind of powder. 132 The increase in the total burning area and decrease in the air space will cause the pressure to accelerate more rapidly than normal and to reach a higher point before the bullet has had time to move forward.
4. The use of too fine or too fast burning powder in heavy charges. This refers particularly to powders fur pistols or small rifle cartridges when used in the larger rifle cartridge«. Such powder« are useful in reduced loads but if charges are increased too much, the pressures will develop so rapidly that they will practically cause all of the powder to burn at once. A slight over-load of these powders is far more dangerous than with the coarser grained and slower burning powders.
5. The use of a heavier bullet than normal. The heavier the bullet, the greater the time and force required to overcome its inertia.
6. A larger bullet than normal An increase in the bullet diameter will increase the force and time necessary to impress it into the rifling and will also increase the friction between it and the barrel.
7. A harder bullet will increase pressures for the reasons already mentioned. However, the variations in hardness of factory jacketed bullets can be ignored with all normal loads. In revolvers, soft bullets are more dangerous than hard ones with heavy loads, as soft bullets up-set gready between barrels and cylinders.
8. A longer bullet than normal will cause some increase in pressure because of the greater bearing surface but this condition does not have any effect until after the bullet has started forward. As an increase in length would of necessity be accompanied by an increase in weight also, the condition in paragraph 5 would apply.
Another factor of importance in connection with the 133 use of heavy loads is the arm itself. 1 refer now to the type of arm. It must be borne in mind that when one is shooting a bolt action rifle, the shooter's face is somewhat removed from the head of the cartridge. If a break occurs in the. head of a case or a primer is pierced, the escaping gas must pass back through or around the bolt, where there arc various mechanical parts to help impede and deflect it. This is not true of most single shot rifles. When shooting these arms the shooter's face is right up on top of the cartridge and when something docs let go, it is likely to be just too bad. Bushed firing pins or other trick alterations of the firing mechanism may be of some use in supporting the normal thrust of the cartridge ease and primer, but when the case gives way these gadgets are just so many more pieces to fly around.
Revolvers and pistols are not so bid when they blow up, as they are held well away from the face of the firer. Fortunately, the force of explosion and the direction of the flying pieces is lateral and upward for the most part. Pieces seldom come to the rear, although they can, and the most that a shooter is likely to lose is a finger or two off his gun hand, which isn't so bad as he will still have six left. But eyes are different; we only have one of these to spare and it seems a pity diat handloaders should risk them by following the guff and ballyhoo of the barnyard ballisticians, who, like children in a sand box, fill cartridge cases up with powder, get away with it by the grace of Cod, and then loudly proclaim to the world that die ballistic engineers of the powder companies don't know what they're talking about.
The illlustration on Plate XI shows the top of a cylinder of a revolver, blown up with overloaded, reloaded ammunition. Whether the owner just didn't know what he was doing or whether he was following some information re-
ccivcd from unreliable sources, I don't know, but he sure did a good job. Note that the "blow" was not caused by one overloaded cartridge. The gas pressure, or the set-back from the cartridge fired, fired the cartridges on either side 134 of it. Had the cartridges in the chambers on cither side of the one fired in the usual manner, been normal loads, it is unlikely that the top would have been completely lifted off the cylinder. Even if it had been, there would have been no expansion of the side chambers, but you can see that both of these chambers are expanded from the overloads that dicy contained.
If you must fool around with these crazy loads, be philosophical about it if you get injured or maimed. Charge the damage off to experience, get a new gun, and use better judgment in the future.
I am closing this chapter on powders with the expressed hope that no reader feels disappointed because there has not been included several yards of printed tabulations showing all the "recommended" charges for the various cartridges with all the smokeless powders dating back to the time of the Spanish-American War. I could have copied these off from various sources, but decidcd not to. Instead, let me again urge the reader to write the powder manufacturers and get from them the latest descriptive folders giving a list of charges for the cartridges he is interested in. Then obtain a supply of cross-section paper, ruled in tenths of an inch., in order to be able to plot down and interpolate any number of safe loads from the charges given in these folders; using the method described on page 128 and illustrated on page 129.
I have the most profound respect for these little duPont and Hercules powder folders. The information in them is authentic and accurate, they tell so many stories, when carefully analyzed, that their usefulness goes far beyond the superficiality of a list of charges which can be lifted out, body and breeches, and loaded into cartridges. Within their limits, they offer the handloader all the facilities of a ballistic laboratory, without the fuss, bother and expense of doing the work.
The first missiles fired from arms using gun powder as a propellant were probably stone and we do know that cast iron balls were used in the early history of such arms, but as neither of these substances are of any use to us for reloading ammunition we can jump forward to the use of lead or alloys of this metal.
Smooth bore, muzzle loading muskets used lead balls-that is—the projectiles were approximately spheres or balls before they were loaded. These arms were notoriously inaccurate, because the "balls" had to be smaller than the bore in order to load them and when fired, bore harder on one side of the barrel than the other, causing them to take a flight like a pitchers curved ball. As their direction of rotation was a matter of chance, both as to degree and direction, the shooting was erratic. Difficulty was encoun-
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