i have both of them. my 357mg load with 158gr xtp hp with lit gun powder shoots about 1 1/2 inc higher at 200 yards then a 150 gr speer hot core with varget powder in my 3030 when sighed in at 100yards. with both a round 2250/2275 fps with my guns. 3030 marlin made in the 50s to my marlin 357 made in 90s
How much lil gun you stuffing in there ? 18 grains {Hodgdon's current listed max.} clocked just under 1900 fps. with 158's out of my 1894c. Even if you do get the velocity stated it is simply not possible for the 158 XTP with a BC of .206 to shoot flatter than the 150 Speer with a BC of .255 when launched at the same velocity. There are also powders that will goose the velocity 150-200 fps higher than what you're getting out of your .30-30 with varget.
