Thread: powder and accuraccy

Originally Posted by blip

Ive been wondering for a while why different powders affect accuracy? Or if its actually the powder or the velocity it drives the projectile at so more a velocity thing and not the actual powder?

In my experience ( no claim of expertise here ) it's a combination of factors including a chosen powder and everything has to come together to find an accurate load. It's where handloading experimentation come in. Choose the brass, a primer and a bullet, make loads with the chosen powder and by varying the charges, if the powder proves suitable, you might find accuracy nodes within certain velocity bands. I usually expect to find an accuracy node with quite to absolutely full cases. I'm happy if this gives me a correspondingly satisfactory velocity. With another powder you may not find any accuracy node/s at all but only by experimenting do you find out. But change the bullet ( brand or weight ) and you might find another powder altogether is the one giving acceptable accuracy and velocity. Possibly a change of brass might affect the load combination as well. I don't think different primers always make such a difference but sometime do.
If starting a load development from square one I use Reloading manuals as an initial reference to decide which powders to start with. I may or may not end up using one of those listed ( although often do ) but at least the info should indicate those powders most likely to give reasonably useful loads for the different bullet weights available.