This breech loader was not the break action design but an earlier version of his concept. It was 1855 when Gilbert Smith submitted his first breech loading carbine to the Board of Ordnance at the Washington Arsenal for testing. His idea was to split the chamber in to two halves and use flexible material – India rubber – for the cartridge case to seal the joint. Gilbert Smith was working on his solution to solve the gas leakage at the breech since the 1850s, and his solution was probably the most suitable for percussion breech loaders. The Board of Ordnance bought 30,362 carbines till 1865. The Smith carbine was the 4th most issued carbine of the conflict after the Sharps, Burnside and Spencer, and probably the best construction. This resulted a wide variety of cavalry carbines and revolvers issued to the troops. Beside this practical reason it was also important that arming the cavalry initiated with a white paper, as only very few, obsolete breech loading cavalry carbines were available in the beginning of the war, so the Ordnance Department had to be open for new firearms concepts just to be able to give something to their horsemen. The cavalry had its special needs of course, and the breech loading concept did fit the mounted use much better than loading any arm from the muzzle. While the US Government was conservative in arming the infantry, and focused solely on muzzle loading arms, the cavalry was a kind of research laboratory for the Ordnance Department, allowing new concept to enter the military system.