.38 rimfire

.38 Long rimfire
Type	Rifle and handgun
Place of origin	United States
Service history
Used by	US Army
Production history
Variants	Short, Long, and Extra Long
Specifications
Case type	Rimmed, straight
Bullet diameter	.374 in (9.5 mm)
Neck diameter	.376 in (9.6 mm)
Shoulder diameter	.376 in (9.6 mm)
Base diameter	.378 in (9.6 mm)
Rim diameter	.433 in (11.0 mm)
Rim thickness	.051 in (1.3 mm)
Case length	0.874 in (22.2 mm)
Overall length	1.382 in (35.1 mm)
Primer type	Rimfire
Maximum pressure (CIP)	13,000 psi (90 MPa)
Ballistic performance
Bullet mass/type Velocity Energy 150 gr (10 g) LRN 980 ft/s (300 m/s) 320 ft⋅lbf (430 J)
Test barrel length: Rifle

The .38 rimfire / 9.5x22mmRF refers to a family of cartridges that have been in service in the United States since the mid-19th century. The cartridges are produced in short, long, and extra long variants.

Much like the smaller .32 rimfire, the rounds were originally manufactured loaded with black powder. In the early 1900s, manufacturers switched to the "new" smokeless powder.

The .38 rimfire was preferred to the .32 rimfire for hunting and self-defense purposes because of its larger diameter bullet and increased muzzle energy.