4.38×30mm Libra

The 4.38×30mm Libra (.17 Libra) is a centerfire cartridge designed for use in personal defense weapons.

4.38×30mm Libra
Type	Personal defence weapon Pistol
Place of origin	Czech Republic
Production history
Designer	Vlastimil Libra
Designed	2002
Manufacturer	Czech Weapons (ČZW)
Specifications
Parent case	.22 Hornet
Case type	Rimless, bottlenecked
Bullet diameter	4.40 mm (0.173 in)
Land diameter	4.28 mm (0.169 in)
Neck diameter	4.90 mm (0.193 in)
Shoulder diameter	6.88 mm (0.271 in)
Base diameter	7.56 mm (0.298 in)
Rim diameter	7.65 mm (0.301 in)
Rim thickness	1.24 mm (0.049 in)
Case length	30.10 mm (1.185 in)
Overall length	41.00 mm (1.614 in)[1]
Maximum pressure	430 MPa (62,000 psi)[1]
Ballistic performance
Bullet mass/type Velocity Energy 45 gr (3 g) Spitzer 2,300 ft/s (700 m/s) 528 ft⋅lbf (716 J)
Source(s): Small Arms Defense Journal

Description

It was designed and has been manufactured by ČZW for use in their ČZW-438 PDW.^[2]

The cartridge is based on a .22 Hornet cartridge converted to a rimless design and necked down to .17 calibre.^[3]

Variants

• .17 Libra [4.38×30mm]: A rimless varmint-hunting and sport-shooting cartridge
• .17 Rimmed Libra [4.38×30mmR]: A rimmed varmint-hunting and sport-shooting cartridge for use with break-open actions
• .17 Libra Magnum [unknown]: A longer, more powerful 4.38mm rimless round for use in pistols or personal defense weapons^{[citation needed]}

See also

• 4 mm caliber
• .17 Hornet