80 grains is a good starting point, what size ball and patch thickness are you using. Usually for most calibers there are 2 two different ball diameters you can use. For example a .50 cal will shoot either a .490 or a .495 ball. Then there's patch thickness. They can range anywhere between .010 to .020. My suggestion is to start with a .490 ball and get several different size patches. If a patch is to thick it will make loading a bit difficult. Consistency will make finding the right combo easier. I shoot 3, swab with an alcohol patch or two then run some dry patches. To get any credible data you must be consistent. I wouldn't concern yourself so much with tinkering with the sights until you can shoot good groups, by all means stay at 25 until that happens. There are no shortcuts when dialing these guns in. Once you figure your load out they are incredibly accurate.