With regular BP, the old rule of thumb was reduce your best 2f load by 10%, and you were with striking distance of your best 3f load. if you hear th round crack like a rifle (and you will know the sound when you hear it), reduce the load till you don't hear the crack. Of course, the correct way is to work up from a low load, finding your most accurate load with the powder/projectile combo. I tend to find with convertional sidelocks and conicals, this tends to be (for me) about 5 grns below where the rifle starts to crack. I seem to get best accuracy from my 1:48's right about here. HOWEVER>>>the current thinking now is DO NOT use 3f in anything over .45 cal as it burns too fast, causing errosion of the lands and grooves by gas pressure.I beleive that clearshot generates a higher pressure than regular bp to start with anyway, with means you want to do 3f of that stuff even less. Check the manufacturer's website, but I me shure they will say 3f in a rifle is a no-no.