RE: Steve Brooks mold.
A 560 grain .45 caliber bullet is going to 1.500"+ long even if it is quite blunt. With an 18-twist .45 you are better off, stability wise, to be no longer than 1.440".
If you are shooting one of the longer .45 cartridges and getting 1350 fps or more you can stretch that out some. At 1350 a 1.460" long bullet should be good. If your up around 1400 fps a bit longer is probably OK.
The only real way to know is to try it and not just when the wind is calm and steady. However, if you push the length to twist thing too much your bullet may be only marginally stable and can give you fits if the wind is blowing and especially if it is gusty.
I do well out to 1000 yards with my .45-70 with an 18-twist shooting a 1.435" long bullet at 1297 fps even when the wind is pretty rough.
A marginally stable heavy bullet can not hold up as well as an optimally stable lighter bullet. Once a marginally stable is slapped with a wind gust it can struggle in vain to regain stability and there is no telling where it will go.
It will take more wind to upset a well stabilized lighter (shorter) bullet and its recovery will be quicker.
Jim Kluskens
aka Distant Thunder
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