Skip to content

Cartridges Manufacturers Glossary Tools Armory

Search matches names, aliases and the text of every page. An arm found by its service designation is found by its alias, not its title.

ARMAG
Operating system
Blowback, roller-delayed

Operating system

Blowback, roller-delayed

Rollers geared against the trunnion retard bolt opening.

Gas, direct impingement Gas, short-stroke piston Gas, long-stroke piston Short recoil Long recoil Blowback, simple Blowback, roller-delayed Blowback, gas-delayed Blowback, lever-delayed Blowback, friction-delayed Manually operated

1 entry

Submachine gunHeckler & Koch MP5
Heckler & Koch · 1966

ARMAG

A free, non-profit reference for modern firearms. Every number is either sourced or derived from sourced numbers by a formula you can open and check.

Browse

Firearms
Cartridges
Manufacturers
Glossary
Tools

This site

About
Methodology
Editorial policy
Attributions

Reference information only

ARMAG is not legal advice, not safety instruction, and not a substitute for a manufacturer's manual or qualified training. Figures are transcribed from published sources and may contain errors; check anything that matters against the source we cite. Read the full disclaimer.

© 2026 Kiarash Farajzadehahary.Content licences are recorded per image and per citation.