The United Kingdom would adhere to smooth bore guns for a rather long time.

In 1850 it held trials with existing foreign rifled breechloading guns designed by Wahrendorff and Cavalli.

[6] The Armstrong guns would be produced at the Royal Works at Woolwich as well as at the new Elswick Ordnance Company founded in Newcastle on 1 January 1859.

In combat and trials, the guns up to and including 40-pounder (4.75 inch) caliber, proved to be very successful after some modifications had been made.

In this test, the Armstrong breechloader could not stand up against newer Rifled Muzzle Loaders (RML) designed by himself and Whitworth.

[10] A more fundamental problem was that the breechloading mechanism could not withstand the explosive force required to give heavy projectiles the speed needed to pierce armor.

Armstrong had improved the Royal Artillery works at Woolwich to produce his breechloaders, but left office in 1863.

These used Armstrong's method of manufacturing the gun barrel, and the first attempts to produce a RML also used his shunt principle for rifling.

The general characteristics of the 23 cm Armstrong RML, like length and caliber were the same as those of the 9-inch Woolwich gun.

The Armstrong method of producing the gun, consisted of making a steel barrel, and reinforcing it with wrought iron coils, so it would not burst from the explosive force inside.

The Armstrong gun retained the original larger number of smaller coils,[14] which was more expensive to make.

On pictures these coils show as humps as the gun gets smaller while it protrudes to the front.

[15] HNLMS Prins Hendrik der Nederlanden was the first significant armored ship of the Dutch Navy, and received the first four guns.