US Ordnance Memoranda No. 14 and a Horizontal Pinfire Cartridge

I have had the reprint of this book for some time and always thought it was a neat resource giving examples of various cartridges tested at the Frankford Arsenal. It is especially pertinent to me as there were experiments on a horizontal pinfire cartridge. The hope was that the front ignition would give higher pressure and a higher velocity which it did. However it was very complex and had many other issues in their trial.

This memoranda was put together in 1873 by Major Treadwell who had been deeply involved with ammunition and ordnance at Frankford Arsenal for awhile. He was mentioned here in the article on the American Civil War pinfire cartridge designed and manufactured by Christian Sharps as he is who asked Sharps to make a new pinfire cartridge for the Army. Treadwell introduces the memoranda as follows:

FRANKFORD ARSENAL,
PHILADELPHIA, Pa.,
April 22 1873

SIR:
The following notes on the performance of metallic cartridges manufactured and offered at this Arsenal for service comparative trial and experiment have been prepared with a view of presenting the subject in a brief comprehensive manner for the information of the Department and are submitted with the hope that they may not prove uninteresting.

As the investigation of the whole subject of metallic ammunition for small arms would open up a field of research far beyond the limits of the present purpose it has been deemed best to confine its treatment in a general descriptive manner to the development of the question based upon trials made by the Ordnance Department particularly at this Arsenal.

Most of the prominent varieties of cartridges herein referred to having been the subject of extended trials the results of which have been given in full and special reports to the Bureau the details of their performance have not been attempted in this place.

I am indebted to Mr Jabez H Gill foreman of machine shop at this Arsenal for the preparation of the very creditable drawings accompanying this Memorandum as well as for valuable suggestions of forms and combinations used in the purely experimental cartridges herein described and for assistance in the comparative and extraordinary tests that have been applied to determine the relative value and strength of cartridge cases as developed by hydrostatic pressure test eprouvette &c.

The mode of application of the pressure gauge as described in the accompanying drawing was devised by Lieutenant William Prince Ordnance Department and adapted to the Springfield breech loading rifle with most satisfactory results.

I have the honor to be very respectfully your obedient servant,
T. J. TREADWELL,
Major of Ordnance Commanding.

To the CHIEF OF ORDNANCE U. S. A.,
Washington DC

The book contains 68 plates of drawings with notes on the arsenals tests. Many compare and contrast the existing service weapon with the experimental cartridge.

CORLISS’
FRONT IGNITION.
EXPERIMENTAL.
CLASS 1.

Remarks.
The Corliss Needle Cartridge for Springfield The needle was attached at the base to a disc crimped into the flange of the case. The point was made to conform exactly with that of the service firing pin. The fulminate was held in a copper capsule in the base of the bullet open to the rear and covered with tin foil.

In consequence of the extremely limited longitudinal motion which the needle experiences from the indentation of the cartridge case the bullet was carefully gauged in the [??] to bring the fulminate almost in contact with the needle point. Notwithstanding the close gauge employed the first 25 cartridges failed entirely to explode in the gun. On examination the fulminate was found to have been forced into the bullet instead of being crushed by the needle point. 30 more cartridges were made with a needle flat fronted and squared at its [??] like the arbor of a watch; which it was thought would effectually explode the fulminate. Out of 18, 5 of them exploded.

Average velocity of service 1320’; of needle 1336′ per second;’ mean variation in %, service 0.3; needle 1.10. It was to be expected the needle cartridge gives a higher velocity but in uniformity is much below the service. A target of 20 shots were attempted to be fired; 13 shots well secured in comparison with service. Practice at 500 yds. Mean absolute’ deviation, Service 0’856; needle 2’169. Corrected angle of eight; Service 1.° 21.’11” needle 1.° 21.’41.” Fouling from 14 shots, service 6 grs.; needle 5 grs. Of the above 13 needle cartridges, 1 cartridge exploded on 1st blow, 3 on 2nd blow, 6 on 3rd blow, 2 on 4th and 1 on 5th blow. Five needle cartridges also failed entirely to explode.

The same want of uniformity that was exhibited by the velocities is here also in the mean absolute deviation. The fabrication of these cartridges was extremely troublesome and attended with no little danger of premature explosion.

The third cartridge pictured below is a surviving example of the cartridge. It is pictured with other examples that are also detailed in this memoranda.