16x from Snipers Mark (from all the mark, curse effect) 17x From -> 2x tree, 2x deadeye, 2x Dying sun, 5x Tincture, 5x GMP, 1x skill -> 17x16 = 272.
You can check the extra effect to Sniper's Mark in calcs, and the calc for extra proj from everything else detailed above is also correct...