The .44 S&W Special is among the older handgun cartridges still on the market, having debuted with Smith's New Century "Triple Lock" revolvers in 1908. With its case lengthened so it would not fit in older top-breaks designed for .44 Russian, it featured a 246-grain lead roundnose bullet moving at a leisurely ~750fps out of the big N-frame's standard 6½" barrel.
Its modern incarnations as a self-defense loading come from a series of medium-frame five-shot wheelguns, beginning with the Charter Arms Bulldog and including a variety of offerings from S&W, Taurus, and Rossi, as well as its use as a downloaded "urban" loading in .44 Magnum revolvers. Exemplified historically by Winchester's Silvertip and Federal's lead semi-wadcutter hollowpoint offerings, these tended to feature bullets of about 200gr advertised at moving at just under 900fps.
Despite being soft lead and not having any jacket to retard expansion, the Federal LSWC-HP had a minuscule hollowpoint cavity and a reputation for iffy expansion through heavy clothing, but hey, even if it didn't expand, you still had a .429" projectile with a sharp shoulder, right?
When CCI started offering the aluminum-hulled Blazer load with a 200gr Gold Dot hollowpoint, it rapidly became a favored choice for self-defense in .44 Special revolvers. A modern, bonded JHP, advertised at 920fps out of a 5.15" test barrel, the projectile was not constrained by the requirement of feeding in self-loaders and consequently featured a hollowpoint cavity that looked like it could do double duty as a shot glass.
Comes now Hornady's Critical Defense offering, using a 165gr version of its patented FTX bullet. The FTX takes a novel approach to preventing the hollowpoint cavity from plugging by plugging it from the start with a little rubber dingus whose job is to initiate bullet expansion by being forced back into the cavity when fired into something squishy.
Further, Hornady tacitly acknowledges the realities of the modern .44 Special market by measuring its advertised velocity claims out of a 2.5" test barrel. A ten-shot string from my 2½" test gun averaged 925.3fps, which actually exceeded the 900fps claim on the box flap, and from the 4" N-frame, the load averaged 996.2fps, which was moving right along for a factory .44 Spl load.
All this comes at a price, however. As can be seen on page 12 of Hornady's LE brochure (pdf here), the round expands as advertised in jell-o, even after going through heavy clothing, but the reduced sectional density of the 165gr bullet means a test penetration depth of 10" after heavy clothing, a performance equaled by such questionable manstoppers as the .380 and 9x18 Makarov (albeit with a slightly larger wound channel.)
Sand Burr Gun Ranch, recommended as ideal for using in the 296Ti and offering a claimed 900fps from the snubbie. I just didn't feel up to the beating from the flyweight gun by then and so I cheated and launched them from the TRS, where a ten-shot string averaged 1042fps. This leads me to believe that they'd have no problem matching the claimed velocity from the shorter tube, and that it might in fact be a little conservative.