Buckbrush, I have the same questions as you do. I just got a new rifle for long range shooting and my biggest question is load development also. Do I load up loads that I might want to try to break in the barrel or do I just go to like Cabela's and buy one of their 100 round ammo deals to break in the barrel.
I do know the other part of your question. I heard that when breaking in a new barrel that you clean as good as you can before going to shoot the gun. Fire one round through the barrel and clean it agian. Sending one or more rounds down the barrel will smoth out any burs that was left from making the barrel. Now send two rounds down and clean the barrel. Then send three and clean. Repeat this process for about 50 rounds shooting 5 round groups. If there is another way out there, I would like to hear about it. In the past I never really paid attention to how to break a barrel in until a couple years ago when I was watching Shooting USA. They brought that up and I started reading more about barrel break in.
Hopefully someone out there will have a answer to the other part of your question. I would like to know the answer too.