FN 503 vs Glock 18

2020–present

1986–Present

Unknown

~250,000 estimated (including all variants)

163 mm

204 mm (8.03 in) standard, 236 mm (9.29 in) on 18C model

91 mm

102 mm (4.02 in) standard, 135 mm (5.31 in) on 18C model

0.59 kg

625 g (1.38 lb) empty (standard), 730 g (1.61 lb) with 33‑round magazine

6 rounds

33 rounds standard, 50‑round drum, 10‑round compact magazines available

Striker-fired semi-automatic

Short recoil, locked breech, striker‑fired Safe Action system

Striker-fired

Safe Action striker‑fire with slide‑mounted fire selector (semi‑auto / fully‑auto)

Fixed three-dot

Fixed polymer rear notch and front post; optional tritium night sights and aftermarket rail‑mounted optics