The other T56 review here on ASC states that the hopup rubber is far too stiff for its low stock velocity. The other guy states that this is really a 400+ fps gun with a 300 fps spring. Installing a softer hopup rubber and / or stiffer spring should fix that easily.
With .25 Bastards, I had to just slightly nudge the hopup on to get the BBs to fly straight. And the trajectory of the BBs outranged every other gun at the game today. Ditto for accuracy. They shot straight and far every time.
But like I said, the weak spring didn't give it the penetration power for the thick brush where we were playing. My M15 had no problems punching through the woods to get me kills. I didn't get any kills with the Type 56, even though I could clearly see my targets and was shooting right at them at about 75-100 feel. The M15 tagged them very easily at that range through the brush, even though it's not quite as accurate.