No, you're misunderstanding the charts.HuntNshoot said:Could I be misreading the charts?
They're only guides to get you in the ballpark of which bushing to use. And not only do they occasionally vary, as you've seen, but usually any given bushing won't actually drop what the chart says it will.
The bushing selection sequence goes like this:
1. Pick the load recipe you want from a powder company's printed load guide or website based on your desired hull, shot weight, velocity, powder weight, primer and wad.
2. From the bushing chart, select the one nearest your desired powder weight, put it in the press and drop some charges, weighing each one and returning the powder and shot to the hoppers each time.
Drop three or four to get the powder stabilized in the bottle, then drop about six, weigh and write down the weights, then add them all and divide by the number of drops to get the average.
If that's close enough to the charge weight you want, then that's the bushing to use. Otherwise, get the next larger or smaller bushing and start over with the testing.
Do that until you find a bushing that actually drops what you want.
If a bushing drops within a half-grain or so more or less of your desired charge it will be okay if you can't find a bushing that gets any closer.
Leave that bushing in the press and use it from then on for that powder weight. It's not likely H110 will vary significantly from lot to lot.