I am not particularly a fan of the 1:48 twist. I'll get to the 'why' of that shortly. But, understand, the twist does not determine the size of the ball that will work best in your gun. The diameter of the bore is the major factor. That can vary slightly even with factory made guns. Unlike others, I favor a larger ball and relatively thin patch for accuracy. Testing using two or more size balls and several patches is necessary to find the combo that will work best in your gun. Now, the reason I am not a big fan is the 1:48 is that, IMHO, it is kinda finicky as to the charge needed for best accuracy and often does not perform well with heavier charges. The slower the twist, the more forgiving the barrel with regard to charges it likes. However (and in this game, there are a lot of "howevers" and "buts") you will find bench shooters who use a 1:48 with whomper-stomper charges and eat up X centers. And they do it while the guy next to them is using a 1:72, or slower and getting similar results. I don't want to get too wordy but one final thought. The G.M. Davis gun museum at Claremore, OK (great museum BTW) has specification information cards with every one of their many-many muzzle loading rifles. Looking at those, one will quickly see that 1:48 is/was far and away the most commonly used twist on the old guns we are trying to emulate today. So, don't sweat it. Try different size balls and different patches with different loads. When you hit the sweet spot, start bragging, make notes and stick with it.