And yet many modern-day shooters fail to realize that .22 Long Rifle training rifles have been used by major militaries worldwide for decades, generally to provide recruits and conscripts with basic marksmanship training before passing to regular service rifle training.

On the civilian side, .22 caliber rimfires have been used for training of novices for over a century, and when it comes to small game hunting, competition shooting, or simple leisure plinking, .22 Long Rifle is the undisputed king.

The Italian gun industry has a long history in the production of .22 rimfire versions of military-style rifles and carbines for civilian shooters: in the 1970s and 1980s, rimfire versions of designs such as the M16, the AK, the Galil and the FA-MAS were manufactured in northern Italy and distributed worldwide under several famous brands, including Mitchell Arms in the U.S.

This background should be more than enough to make connoisseurs come to the realization that Italian-made .22 rimfire carbines such as the Chiappa M1-22  and the Chiappa MFour-22 – two long-standing mainstays of the Chiappa Firearms line – are an excellent choice for training, range shooting or plinking.

The MFour-22 carbine is built around a black polymer upper and lower receiver; the 16-inch barrel and some small components are still made out of steel.

The lower receiver comes with a standard AR-15 type pistol grip that can be replaced with any AR-compatible grip currently available on the market. The MFour-22 is built to retain the classic manual of arms of the M4 carbine, and as such it comes with a T-shaped charging handle, a safety switch on the left side and a fenced magazine release button on the right side.

The polymer stock of the MFour-22 retains the look and feel of the classic M4 carbine buttstock in all variants, but the MFour-22 GEN II rifles are not compatible with original or aftermarket M4-type stocks, as they feature a single polymer mold buttstock, all in one with a fake buffer tube and available only in what would be the fully extended position.

The MFour-22 GEN II PRO models, on the other hand, offer full MIL-SPEC compatibility – and this includes a fully collapsible stock, adjustable on six different positions, mounted on a buffer tube.

In all variants, however, the Chiappa Firearms MFour-22 is a straight blowback-operated design, employing a cast aluminum bolt carrier with integral recoil springs whose design was inspired by the Ciener Atchisson MKIII .22 conversion unit for AR-15/M16 rifles; as such, it does not require a recoil buffer.

The MFour-22 GEN II carbine comes with a classic two-parts polymer handguard, a Delta Ring and an AR-15 front sight base; the MFour-22 GEN II Pro ditches all of the above in favour of a full-length top MIL-STD 1913 Picatinny rail for optics and a monolithic quad-railed free-float handguard molded into the polymer upper receiver.

The GEN II variants with a classic handguard and front sight also offer other cosmetic features such as a step cut barrel, a front sling swivel, and a fake bayonet lug that is not compatible with any existing bayonet; the GEN II Pro carbines come with a heavy profile barrel instead.

In all cases, the barrel is 16-inch long and comes with six right-handed grooves, a 1-in-16" rifling pitch, and a fake flash hider given how the .22 Long Rifle caliber does not develop a significative muzzle blast. The simulated flash hider is kept in place by a screw and can be removed to be replaced by a functional flash hider or (where legal) by a silencer.