This marketing slogan of the early 1900s described pistols chambered in the lowly .32 ACP cartridge. The guns were touted as being good for everything from home defense to assassinating important persons to self-defense against brown bear. To the modern reader, such claims appear outrageous, but why were they taken seriously back then? The rounds that 32ACP superseded were mainly the black powder .320 revolver cartridges loaded with lead round nose bullets. 80 grain unjacketed bullet at about 550fps lacked penetration and typically did not expand. Five or six of those from a revolver were rather less likely to end a fight than eight jacketed pistol bullets propelled by smokeless powder at 900fps. Neither round would equal the performance of .38 Automatic or similar, but then neither would the larger guns fit pockets, whereas the .32 could. Note that neither the higher velocity nor the greater penetration were at all significant for target shooting, so the Olympic pistols use .32 S&W Long even today. Much the same situation obtains with 22LR and 22WMR. The ballistic advantages of the higher velocity round are meaningless for target shooting and recreation plinking, while the lower cost of the 22LR makes it quite attractive. On the other hand, people who shoot things other than paper may find 22WMR worth considering. First, let’s look at the bullet construction. 22LR bullets are usually plain or plated lead, with a couple of pre-fragmented rounds available. 22WMR, on the other hand, comes in plain lead for plinking, as ball for penetration (capable of defeating the skull of a 300-pound wild boar straight on), hollow point for self-defense and frangible for varminting. Next comes the velocity difference. Although 22WMR appears to be a waste for use in pistols due to the slow powders used, it still gives the same performance from a pistol as 22LR out of a rifle. Out of the rifle, the faster cartridge pushes 1950fps with 40 grain bullets and at 200 yards (!) the velocity is the same that 22LR produces at the muzzle. That becomes significant both for resisting wind drift and for minimizing projectile drop. In sum, just the 32ACP in the early 1900s, 22WRM provides a valuable improvement in performance over 22LR without adding much weight or bulk.
22WMR is obviously a marginal round for self-defense but it is far from useless. Its niche is similar to the 5.7×28 FN cartridges, for use in lightweight compact weapons. For example, the upcoming Keltec RMR30 is almost exactly half the weight of an AR15 with the same length barrel. If necessary, it may be fired with one hand. Each extra loaded magazine adds 6.4oz vs. 16oz for the standard AR15. This may be of small importance to professional weapon users, but paramount to backpackers or to those who cannot lift much weight due to a handicap. RMR30 itself is not designed as a front-line combat weapon. For example, the telescoping stock is lightly built and wouldn’t last in melee fighting, but then neither would the folding stock of the “paratrooper” M1A1 carbine. As configured, it proved 100% reliable over hundreds of rounds and quite accurate as well: at 25 yards, I can put the entire 30 round magazine into one 1/2″ hole using the 3x scope and CCI Maxi-Mag ammunition. That’s with my elbows rested on a table, not from a machine rest. The crisp trigger shared by RMR30 and PMR30 is a big help with the accuracy. The imperceptible recoil helps as well. When I take it to the range, I always end up with 10-11 year old kids wanting to try it — the light weight and the variable length stock make it a viable firearm for them. The sound suppressor works quite efficiently because the amount of gas at the muzzle of a 22WMR isn’t large but it exits at a fairly high pressure. The illuminated 3x scope works well for precision shooting — for defensive use, a red dot allowing co-witnessed backup sights would be more appropriate.