You'll likely get increased velocity if you measure your BH by VOLUME. Now I imagine many are going nuts after that statement but, I'll explain.
It has always been suggested by Western to measure by volume. However, Western also gave a conversion number for those who wanted to weigh the propellant, which is .7.
Because of the cylinder size variation, BH varies in weight from lot to lot number. This has been known for well over a decade.
Examples ONLY. Take a 120gr VOLUME charge of lot#26 and weigh it and it could weigh 91grs average. Lot#27 could weigh an average of 82grs. Do the same for lot#29 and it weighs 96.1grs average.
So if you're weighing charges ONLY, you could very well be slighting yourself on velocity.
VOLUME IS VOLUME. Get a quality volume measure and set it at 120grs. Fill it with BH and tap if you like. VOLUME IS VOLUME. Do say a dozen of them and weigh each, then average those weights. Then.... use that average weight. Remember.......... any time you change lot numbers, repeat the process.
In the example above for lot#29, that is the weight of 120grs VOLUME, 96grs average. There are a few of us shooting a 1,000yd match next month and are using the same lot. 96grs is the average for each of us .