I'm curious to know how are you guys breaking in a new barrel and begin your load development. I have a 6.5 PRC and a 30 Noer that I need to break in and start new loads. How would you go about it?
Custom barrels i don't spend much time on break in. Usually Ill shoot 5 or 10 down it, strip it clean then shoot another 10 or 15 then clean. After that full send mode.
Like @Creedmoor shooter said, I do about the same thing. I usually use the first 50 shots or so on the barrel to find some loads and fire form some brass. Then I refine the load with the once fired brass until I get it where I want. Most barrels speed up around the 100-200 round mark. I shoot until the velocity plateaus, then back off the powder charge until I get back into the node I found before the barrel sped up or bump up in powder to get the next node if I don't hit pressure.