What is a Universal Action?

[Kerplow]

I see this term used in reloading manuals as a tested firearm type. What is a universal action?

[G-forceJunkie]

a bench mounted "gun" that they do the load tests with. Basically an action that they can screw any caliber barrel in and they are often plumbed up with all sorts or gauges tomeasure the pressure and such.

[G-forceJunkie]

https://sydortechnologies.com/ballistic-impact-testing/firing-point/

[Kerplow]

That makes perfect sense, thank you. Google just brings up results for universal action wrenches.