The other thing they say is to be sure and use a 250 gr. bullet.
Congratulations, pard! They're right, 'tho if you buy the BlackDawge cartridges, they'll be a 230 gr. bullet ... but that'll work, too.
We need to get you started reloading. And learn to drop the "L" in 45 Colt.
They UNofficially added the "Long" to keep the confusion down because of the 45 S&W (45 Schofield) cartridges. And the "L" or Long ISN'T official - 'tho you'll find it many places by the uninformed ... INCLUDING the Colt
(tm) website.
OK -- folks - let the flaming start!