M3 Grease Gun vs MAC-10

1942–1945

1966–Present

Over 680,000

~250,000 estimated (including U.S., Brazilian, and Asian licensed production)

757mm (29.8 in) stock extended / 579mm (22.8 in) stock folded

254 mm (10.0 in) with stock folded; 330 mm (13.0 in) with stock extended

203mm (8.0 in)

127 mm (5.0 in) for 9 mm version; 127 mm (5.0 in) for .45 ACP version

3,700g (8.15 lb) empty

2.5 kg (5.5 lb) empty, .45 ACP version; 2.3 kg (5.1 lb) empty, 9 mm version

30 rounds

30‑round box magazine standard; 20‑round (compact) and 40‑round (drum) options available

Blowback, open bolt

Straight‑blowback, open bolt, telescoping bolt with simple recoil spring; selective‑fire (semi‑auto and full‑auto)

Selective fire (semi/full auto)

Single‑stage mechanical trigger with manual safety lever; full‑auto fire only when selector set to "auto"

Fixed blade front, flip-up L-type rear (100 and 200 yards)

Fixed, low‑profile iron sights: simple blade front post and notch rear; optional aftermarket tritium night sights