Maybe spin or yaw

[Lead melter]

Had an interesting experience last week that maybe some of you fellers can help explain.

I removed the 2X Weaver handgun scope from my youngest sons' Marlin 1894-P and mounted a little Leupold VX-I 2-7X. Went to the range to zero with our "play" load of a Lee 240 grain SWC sized at .430", over 10 grains Unique, at average 1389 fps.

Zeroed at 25 yards, then moved out to 100 yards just to see how much drop we had.

Lo and behold, bullet impact was about 14" low, but 16" left! Moved back to 25 yards and zero was just fine.

Shot some RD TLC-432-265 over 18 grains L'il Gun, 1550 fps, bullet impact was about 12" low, but right on the money horizontally.

Next fired Hornady 265 grain "J-word" slugs over 20 grains L'il Gun, at 1629 fps, and impact was about 10" low, but once again on the dot horizontally.

Back to the Lee boolit...same result.

Anybody got any ideas about why this happened?

:veryconfu

[subsonic]

Is the scope not square with the bore?

Just guessing.

[Buckshot]

............What kind of group did the wandering Lee give ya at 100 yards?

............Buckshot

[Lead melter]

Subsonic,
Yes, the scope is square. That scope was at one time mounted on that rifle, and very little adjustments were needed in order to bring it into zero.

Buckshot,
I got groups of about 8" at that range. This is , as I know, not the most accurate boolit for this gun, but it is cheap and deadly out to 50 yards [1 1/2" groups]. We use it to squirrel and rabbit hunt and there are no "crawled away to die" critters after the shot. Helps keep in practice with a rifle, and North Carolina has no restrictions on caliber of use for small game.

[44man]

I blame the really stupid rate of twist that Marlin uses where stability with any given boolit is an issue. The velocity range for accuracy is so tight that I wish I could get a custom replacement barrel. Some boolits won't shoot at all.
What I don't understand is the tremendous drop you are getting. I don't see more then an inch or two even with my revolvers. But I start at 50 yd's so I don't know what a 25 yd zero will do.