jm -- yes, this past season I went with the 225gr SGK (get skunked, oh well, wish I had a field report to share). I started with three bullets the 180gr SSP, the 200gr FTX, and the 225gr SGK. By the time I got loading and realized I'd probably be too fast for the SSP and FTX, I concentrated on the SGK, I was down to the wire time-wise. My buddy started and ended his load development with the 200gr Interlock SP, and I might go that route next season. The trajectories of all the bullets are freakishly similar, but the 225gr maintains more velocity and energy past 200-250yards.
I will check out the Marlin forum for sure. I have seen that test before but I didn't remember any specifics about the FTX. The SGK gets questionable at ~235 yards (falls below 1900fps) whereas the FTX would still be within its range per Hornady at 300 yards. Past 300 and the trajectory would become too difficult (for me) to estimate holdover. Regardless, I've never had access to a 300 yard range and I would most likely pass on a 300 yard shot. And if I could not get into a solid shooting position I would probably pass on a 250 yard shot.
I have noticed though that light loads with the 180 and 200gr bullets would be suitable youth loads, the recoil is quite mild. And very accurate. I might even try a Trail Boss load with handgun bullets.
My buddy has some of the Nosler Accubond and Partition, they are loooong bullets. The AB would probably work in my chamber and not reduce my capacity (the Barnes 200gr as well), the Partition, maybe not. I haven't decided if it's worth the cost to try a box. Seeing both bullets side by side though, I can't understand how the Partition has a higher BC.