M4A1 vs SKS

1994–Present

1945–1990s

~10,000,000+ units (including all variants and licensed production)

Over 15 million

838 mm (33.0 in) stock extended, 756 mm (29.8 in) stock collapsed

1020 mm

368 mm (14.5 in) standard; 406 mm (16 in) for the M4A1 SOPMOD variant

520 mm

3.07 kg (6.8 lb) empty, 3.74 kg (8.2 lb) with full 30‑round magazine

3.85 kg

30 rounds standard STANAG, 20‑round low‑profile, 40‑round drum, 60‑round Beta‑C‑Mag available

10 rounds (fixed)

Short‑stroke gas piston (M4A1 variant) with rotating bolt; original M4 uses direct‑impingement

gas-operated, tilting bolt

Two‑stage military trigger, full‑auto only selector on M4A1; semi‑auto on standard M4

two-stage

Standard: A2 front post and rear flip‑up aperture; optional: MIL‑STD-1913 Picatinny rail for aftermarket optics, tritium night sights, or holographic sights

Iron sights