using 7.62x54R bullets for loading .303

[Parashooter]

. . .how do most of you "start low and work your way up"? . . . Do you guys make like 5 rounds at a minimum load, increase the load and make 5 more, increase and make 5 more, etc., then keep them all separate and see how each load performs?

. . . And how in the world does an average Joe measure chamber pressures?

I save some time and money by working up medium-size military rifle loads in 1/2-grain increments (less for small cartridges) and loading just 3 cartridges at each step. A load that appears safe and groups well for three shots is worth loading up 10 for the next trip. If it performs well for 10 shots, it's a good candidate for more testing, minor tweaking, and possible adoption. One thing you don't want is to use up your entire supply of a powder on load development and discover you can't find more from the same production lot.

Pressure measuring equipment is generally unavailable to us "average Joes". Experience with moderate loads, combined with a low-cost chronograph, lets us learn to make reasonable estimates - or at least recognize when we're pushing the envelope too hard.