First, a little history preceding the 1-pounder pompom. One might claim that the pompom was to the Hotchkiss revolving/revolver cannon, as the Maxim machine gun was to the Gatling gun: i.e., fully automatic versus fired by a manually operated hand-crank, each size to fill a particular niche. Couple of images attached of the pompom’s techno-predecessor. The first revolving cannon is manned by a German gun crew, likely somewhere on the plains of Africa, and the second—to maintain the continuity and integrity of this thread—on a smaller mount nicely appropriate as a mountain or landing gun.
Hate to burst your balloon, when belief in the pompom as the gun that almost won the Second Boer War lurks not that deeply in the heart of every red-blooded South African, needing only a pint or two of King’s Blockhouse IPA to find expression, BUT.... It was, I fear a highly overrated gun. I concede it saw use in virtually all of the world’s navies, and not a few of its armies, but at the same time, it fell out of favor just as fast as it had come onto the scene.
The gun is actually the Maxim-Nordenfelt, being that Maine Yankee Hiram Maxim, by fair means or foul, took over Thorsten Nordenfelt’s merchant-of-death empire, before his own fell in turn to Vickers & Sons. Perhaps ideal for bold, mobile, and hard-riding Boers to potshoot at British field batteries—pushed far too forward and thus becoming obvious targets—the pompom saw rather greater success at the beginning of the war than at the end, after British field battery doctrine had been changed to meet the threat. The article you post, although with not a few errors, is correct in its criticisms only so far as it includes them, short range and too light rounds being paramount. It misses a couple of other disadvantages of the 1-pounder pompom, viz., the field equipment, when including the gun carriage and limber carrying sufficient rounds for a largish automatic gun, required a six-horse team for a movement of any real distance (big investment in horseflesh for a light artillery piece), and hardly least, those rounds were muy expensive, leading more than one European monarch or his treasurer to reject the pompom’s adoption.
The U.S. Army, which despite poor judgment on ordnance adoption on more than one occasion, did exhibit the wisdom to acquire light field guns that could see multiple uses. For example, filling that bill might be a gun, on somewhat modified field carriage variants, that could serve both as a cavalry-accompanying light fieldpiece and as a beach defense gun protecting remote harbor defense batteries too large to defend themselves against a raid by a naval landing party. On that basis, the army acquired two batteries of 1-pounder pompoms c1899–1900, both to use against Philippine insurrectionists and as a candidate to defend HD batteries. The field artillerymen in the P.I. found the pompom too heavy and unwieldy to negotiate the bush, and the coast artillerymen felt they needed a longer-range piece, with both gunners wanting a piece capable of firing shrapnel. Which gets us back to the pompom’s serious disadvantages in wartime practice.
The field equipment, as alluded to previously, was heavy, requiring the same size team as for a 3-inch or 75mm fieldpiece, but with one third the effective range. As an automatic gun, the pompom’s need for ammunition must fairly be described as profligate, i.e., having an inexhaustible need/greed for rounds, which it must be pointed out were disproportionately expen$ive (and often the deal breaker). Despite what the article whose URL you provided doth claim, the 1-pounder and indeed even the 6-pounder used rounds too small to accomodate shrapnel, then felt to be an essential part of a gun’s repertoire. As an early 20th century design challenge to its commissioned junior officer-students serving at Sandy Hook Proving Ground, the U.S. Army instructed them to come up with a light field gun that could not only serve in a multitude of roles, but...BIG BUT...could fire shrapnel. Those bright young lads arrived at the smallest piece that could meet the need for that type of round: the 2.38-inch field gun or 7 1/2-pounder. The piece was a handsome one, but a one-off: turns out the army’s already-in-service 3.8-inch howitzer—lighter, more compact, and delivering a far larger and more effective shrapnel round at a greater distance—already filled the bill. Same as with your vaunted 1-pounder pompom: whatever it did, something else in the ordnance cupboard did it better, the automatic nature of the pompom notwithstanding and even defeating.
Following some success during the wars taking place at the end of the 19th century—the USN used them most effectively as a defense against Spanish torpedo boats—the pompom became moribund during the first decade of the new century. It enjoyed a rebirth during WWI as an AA gun, briefly in the U.S. Navy, but as you’ve written, rather longer in the Royal Navy and its Commonwealth offshoots. The article you cite claims a natural size progression from 1-pounder through 1 1/2-pounder to 2-pounder. Not so: the 2-pounder appeared before the 1 1/2-pounder, with the latter a compromise because of space limitations on some British destroyer classes. The 1 1/2-pounder mount as designed, however, proved heavier than that for 2-pounder and was soon withdrawn as unsatisfactory. The article also declares, “By 1907 with the Vickers machine-gun replacing the less reliable Maxim...” The Vickers MG was a Maxim gun, and of course there were improvements over the years as for any gun having a lengthy history.
I likes ‘em and share your interest, but the true history of pompoms, particularly in army hands, was not that rosy for the variety of reasons I’ve chronicled here.