How did people determine chamber pressure in the years before computers and fancy electronics? Well, by squishing a calibrated slug of copper. Factories would convert rifles specifically for pressure testing use by adding a pressure ring around the chamber, drilling a hole in it, and then threading in a gage to crush a block of copper. This Mosin Nagant is an excellent example of the system, complete with the all the testing apparatus!
April 28, 2015 Ian McCollum Competition, Heavy MGs, Interview, Revolver, Sniper Rifles, Submachine Guns, Video 13