Returning to the 10mm Pistol as an example, the Hardened Receiver only adds 5 damage. You get more crit damage with the calibrated receiver than with the corresponding damage receiver. Four times is twice as much as two times, so the calibrated receiver doubled the crit damage compared to what it would have been otherwise.
Compare this to the calibrated powerful receiver's crit damage, which is four times the normal damage (98 = 4 x 24.5). 308 receiver's crit damage is twice the normal damage (57 = 2 x 28.5). That's why you see the calibrated powerful receiver's actual damage at 24.5, which is half of 49. They're playing on survival, so the actual, normal damage is cut in half from what's listed in the Pip-Boy. The numbers below are without these perks. Those extra perk tests aren't really relevant to this question, so I've omitted them. They also did some tests with and without the Rifleman and Better Criticals perk. They used a combat rifle, and compared the Calibrated Powerful Receiver to the. They tested crits on survival difficulty versus an enemy with zero damage resistance. I've seen this reported in a couple forum threads, including one from Reddit with actual research by a user called 'jacknbox'. Calibrated Receivers and, presumably, Photon Capacitors double crit damage.
