You who have followed my forum for long are aware of how I push the importance of measuring each individual gun and ordering a mold that will produce bullets that fit. Also, in lapping if necessary. The following is a very strong case in point. It's a bit extreme, but these kinds are the ones that runs cost into the clouds if one starts buying molds in hopes of getting a good one.
In a recent post reguarding a 9.3 rifle, which has a 'nominal' barrel diameter of .366, I recommended that the customer send a throat and barrel slug so there would be no guessing in cutting a mold.
His slugs and order arrived friday and I happened to be cutting LFNs when it arrived, which is what he wanted. On measuring his slugs, I found that groove diameter of his barrel is in fact .370!!! So in fact he has a 9.42 rifle, not a 9.3! In short order I cut him a mold which uses .375 gas checks, and wrote out instructions for him to follow. He had tested some commercial cast bullets with poor results, and had he bought one each of every production mold on earth, his results would have been total discouragement. He could have easily spent several hundred dollars and ended up with a pile of pretty junk, but instead, because he took my advise and measured, when his mold arrives sometime next week, the first bullets he shoots will be accurate, and the bullets will handle full power loads or near it with superb accuracy.
This is a dramatic example, but it is consistent to a lesser degree on the majority of firearms. ALL ARE INDIVIDUALS. TREAT THEM ACCORDINGLY AND ELIMINATE HOURS OF FRUITLESS EXPERIMENTING AND TESTING OF LOADS WHICH WON'T SHOOT! MANY PEOPLE SPEND MORE MONEY TRYING TO DEVELOP LOADS WITH BULLETS FROM A CHEAP MOLD THAN THEY WOULD HAVE FOR A PRECISION CUSTOM FITTED ONE THAT WOULD DELIVER PERFORMANCE THE FIRST TIME OUT TO THE RANGE! YET THE EXPERIMENTING IS FUTLE AND NEVER CAN DELIVER A GOOD LOAD IF THE BULLETS DON'T FIT THE GUN.
