Ask Ian: What is Headspace? (And Why It Matters) (ad-free)
🕑 Added 2022-12-16 12:00:03 +0000 UTCFrom LongBeef on Patreon: "What exactly is headspace? And how important is headspace in old milsurp guns vs. more modern guns?"
Headspace is basically the amount of play a cartridge has in a chamber. There has to be some to account for manufacturing variations in guns and ammunition, but too much or too little can cause problems. Too little can cause extraction problems and poor accuracy. Too much can cause poor accuracy as well, and also shoulder separations, case head separations, and kabooms.
Here's a neat prototype rifle that operates based on headspace: https://youtu.be/SfuwgVCh79M
Also shown in this video:
Ian's Terrible Krinkov: https://youtu.be/JT1cNraZjp0
Turkish "Enfauser": https://youtu.be/3VQjo3MhgVw
Comments
Guido Schriewer
where are aluminum or steel cases in that as they expand not as brass?
Guido Schriewer
was that your lmg? can get scary. had a by39 bullet REALLY pushed into the case SOMEHOW. glad I noticed instead of touching that off.
Hozi
Love these videos, very informative.
According to the SAAMI Glossary: HEADSPACE The distance from the face of the closed breech of a firearm to the surface in the chamber on which the cartridge case seats. 1. BELT: A type of chamber design in which the cartridge seats in the chamber on an enlarged band ahead of the extractor groove of the cartridge body. 2. MOUTH: A type of chamber design in which the cartridge seats in the chamber on the mouth of the cartridge case. 3. RIMLESS: A type of chamber design in which the cartridge seats in the chamber on the shoulder of the cartridge case. 4. RIMMED: A type of chamber design in which the cartridge seats in the chamber on the rim or flange of the cartridge case. HEAD CLEARANCE The distance between the head of a fully seated cartridge or shell and the face of the breech bolt when the action is in the closed position. Commonly confused with headspace.
Terry
I remember having a headspace and timing gauge for checking an M2.