Popular hunting gauge. Lighter recoil than 12 gauge. Excellent for upland birds and youth shooters. Good all-around choice.
Type: Shotgun
Introduced: 1870, United Kingdom
Parent case: None
Standardization: SAAMI
Bullet diameter: 0.615" (15.63 mm)
Case length: 2.75" (69.85 mm)
Overall length: 2.75" (69.85 mm)
Max pressure: 12,000 PSI
Rim type: Rimmed
Primer: 209 Shotshell
Typical twist rate: N/A (smoothbore)
Muzzle velocity: 1100–1700 fps
Muzzle energy: 1200–2500 ft-lbs
Effective range: 40 yd
Primary use: Hunting, Target
Production status: Active
Also known as: 20ga · 15.6x70mm
History: Standardized with other gauges in 1870s. Less popular than 12 gauge but significant following. Preferred by many upland hunters for lighter weight.
Notable firearms: Browning Citori, Remington 870 20ga, Beretta 686
Similar cartridges: 12 Gauge, 28 Gauge