I was shooting the 250gr TEZ with Pyrodex pellets 100gr. 
I bumped up to the 290gr TEZ with Blackhorn 209 100gr by volume, for an elk tag I drew this fall. 
(.50cal CVA Optima V2)
They both group awesome and there was no noticeable shift in POI. I did not have to make any adjustments to my sights. 
Those powder combinations with those bullets impressed me!