http://www.researchpress.co.uk/index.php/ammunition/104-experiments1875

Retrieved: 01/08/2015


Ammunition
Report of Experiments

Category: Ammunition
Written by NRA(USA)

New York, December 20, 1875

To the Directors of the National Rifle Association:

Gentlemen - The experiments commenced during the last Summer, to determine the proper charge of powder to use in long range shooting in the Remington Creedmoor Rifle with a swedged bullet, composed of fifteen parts lead and one of tin, weighing 550 grains, have been continued since with considerable regularity, and completed within the past few days.

The results are herewith submitted for the information of the members of the Association.

The practice was at 500, 800, 900 and 1,000 yards.

At 500 yards, seven kinds of ammunition were used, viz.: 90, 100 and 105 grains with a lubricant, and 100, 105, 110, and 115 grains without a lubricant.

At 800, 900 and 1,000 yards, eight kinds of ammunition were used, viz.: 90, 95, 100 and 105 grains with a lubricant, and 105, 110, 115 and 120 grains without a lubricant.

Fifty shots of each kind were fired at each of the distances, except that there were but thirty and forty shots of the 120 grains cartridges fired at 800 and 900 yards respectively.

About half of the 90 grains ammunition were factory made. All the rest were made by the undersigned. The powder used was the same in all cases (Hazard F. G). The shells were all new (of the long kind), none being reloaded. All the balls except a few first used were carefully weighed, and those used in the same score never varied as much as one grain. The powder was also carefully weighed in all cases, and never varied one quarter of a grain to a charge. Generally, the scores were made of ten shots each, after the correct elevation had been obtained.

To ensure accuracy of aim all the shots were fired over a camp stool. The shooting was continued without regard to weather, some times in heavy rain, and some times in very high winds, shelter having been provided for the purpose.

For locating the hits with precision, the targets for most of the shooting were lined off with one vertical line, marking the centre of the length of the target, and three horizontal lines one foot apart, the centre one marking the centre of the width or height of the target.

At no time was the wind gauge very carefully manipulated for the purpose of making large scores, but the elevations of the hits were noted with great care, as the relative merits of the different ammunition could be correctly determined only by a comparison of the deviations of the hits from a horizontal line. At the end of each day’s shooting the distance of each hit from the centre horizontal line was measured, and the average distance per shot of each score computed and recorded on a table prepared for the purpose. When the fifty shots of a particular kind of ammunition had been fired at a given distance, an average of the deviations of all the hits was computed and recorded.

Page 2 of 3

The following is the result of the practice at 500 yards, with the different kinds of ammunition, placed in the order of their merit, as determined by the above plan.

100     Grains  without lubricant,      average deviation       from horizontal 4 30-100 in.
105     "       with    "       "       "       4 66-100 in.
100     "       "       "       "       "       4 92-100 in.
105     "       without "       "       "       4 94-100 in.
110     "       "       "       "       "       5 49-100 in.
115     "       "       "       "       "       6 44-100 in.
90      "       with    "       "       "       7 36-100 in.
It will be noticed that the deviations in the four kinds of ammunition first named vary but little, there being but 64-100 of an inch between the highest and the lowest. It would seem, therefore, that for 500 yards shooting there is not much choice between 100 and 105 grains, with or without lubricant. Indeed, it is reasonable to suppose that a repetition of the test might bring either of them at the head of the list.

Although the scores made cannot be used as a test of merit, it may be added, that the average value per shot of three of the four kinds of ammunition first named were the highest obtained at 500 yards, according to Creedmoor system of counting. In this practice twenty-one consecutive bull’s-eyes were made with 100 grains without lubricant, followed by eleven with 105 grains without lubricant, under a fresh easterly wind.

At 800 yards the following results were obtained, viz.:

105     Grains  without lubricant,      average deviation       from horizontal 7 96-100 in.
105     "       with    "       "       "       8 18-100 in.
115     "       without "       "       "       8 86-100 in.
100     "       with    "       "       "       9 00-000 in.
120     "       without "       (30 shots) "    "       10 00-000 in.
95      "       with    "       "       "       12 00-000 in.
110     "       without "       "       "       12 74-100 in.
90      "       with    "       "       "       16 68-100 in.
As in the 500 yards practice, this shows but a slight difference between the deviations of the four kinds of ammunition first named, there being but 1 4- 100 inches between the highest and the lowest. It may also be said that the scores made by the four first named were the four highest out of eight

At 900 yards the results were as follows:

115     Grains  without lubricant,      average deviation       from horizontal 8 80-100 in.
120     "       "       "       (40 shots) "    "       11 30-100 in.
105     "       with    "       "       "       11 64-100 in.
105     "       without "       "       "       11 68-100 in.
90      "       with    "       "       "       13 00-000 in.
100     "       with    "       "       "       13 54-100 in.
110     "       without "       "       "       14 38-100 in.
95      "       
with    "       "       "       16 04-100 in.
This table shows a difference of 2 50-100 inches in the deviations of the two kinds of ammunition first named, but a remarkable uniformity in the deviations of the 2nd, 3rd and 4th named, and between the 1st and the 4th, a difference of only 2 88-100 inches. As at 800 yards, the scores made by the four first named were the four highest out of eight.

At 1,000 yards the results were:

115     Grains  without lubricant,      average deviation       from horizontal 12 20-100 in.
105     "       with    "       "       "       14 62-100 in.
110     "       without "       "       "       14 66-100 in.
120     "       "       "       "       "       14 87-100 in.
100     "       with    "       "       "       15 64-100 in.
95      "       "       "       "       "       16 30-100 in.
105     "       without "       "       "       18 00-000 in.
90      "       with    "       "       "       18 02-100 in.
In this record there is a striking similarity to that of the 900 yards, in the difference between the deviations of the two kinds of ammunition first named, and the uniformity in the deviations of the 2nd, 3rd and 4th. In fact, the entire tables closely resemble each other, the principal difference being found in the leap made by the 110 grains from seventh position in the 800 and 900 yard tables to that of third in the 1,000 yard table, and an equal retrograde movement on the part of the 105 grains without lubricant.

Page 3 of 3

It will be noticed that throughout these tests, up to 1,000 yds., the 105 grains ammunition, both with and without lubricant, has shown great merit. In the four ranges the 105 lubricated stands second three times, and third once. The 105 without lubricant stands first once and fourth twice, only at the longest range dropping back to seventh position.

It will also be noticed that while the lighter ammunition produced the best results at 500 yards, it gradually gave way in falling back to longer distances to the heavier, thus the three first positions in the 500 yard table are filled by 100 and 105 grains; in the 800 yard table, by 105 and 115 grains; in the 900 yard table, by 115, 120 and 105 grains, and in the 1,000 yard table, by 115, 105 and 110 grains. Also, that the 115 grains ammunition stands sixth on the 500 yard table, third on 800 yard table, and first on both the 900 and 1,000 yard tables; and that in both the latter distances its average deviation from a horizontal is considerable less than the ammunition holding the second place.

From this it may be reasoned that the longer the range the more powder should be used, and so far as these experiments show such reasoning would be sound; but the general opinion is that the increase in the powder charge which may be made to an advantage is very limited. Indeed, until recently, it was thought that the limit had been reached at 100 grains. These experiments have, however, satisfied the undersigned at least that as high as 115 grains, and possibly 120, may be used to advantage at 800, 900 and 1,000 yards. It is also thought that that charge of powder will produce improved scores at the longer ranges of 1100 and 1200 yards. This opinion is sustained by the fact that in all these tests the elevations were lowered in proportion to the increase in the powder charge.

Had the weather permitted, these experiments would have been continued to the longest distances, and it is hoped that when the Spring opens some other member of the Association will undertake to devote some time to this fascinating study, and by careful experiments determine the advantage or otherways of increased charges at the extreme ranges of 1100 and 1200 yards. If it can be shown that a ball weighing 550 grains can be thrown 1200 yards with tolerable accuracy, a new sensation will be created, calculated to enhance the growing interest in long range shooting.

Some 2,250 shots were fired in connection with these experiments, and the information to be derived from the tables, compiled from the records kept, would be exceedingly interesting to the Amateur Rifleman, but time will not permit, at present, of giving anything more than the exhibit herein made of the relative merits of the different kinds of ammunition, tested at the four ranges named; but an effort will be made to lay before the members of the Association, before next Spring, a number of facts relating to atmospheric and other influences which affect the flight of the ball, which it is believed will prove not only interesting but instructive.

All the records of these experiments have been kept by our enthusiastic friend Mr. Carrick, to whom the long range shooters, and the President in particular, are greatly indebted for his voluntary services upon the Range during the past two years.

Respectfully submitted.

ALEXANDER SHALER,
President

From: National Rifle Association (USA), Annual Report 1875