Now that I know my mfg. 3d Q. 1886 Model 1884 has no serial # records , I wonder if someone can help me understand the trajectory of the rifle.

I am shooting factory loads from Black Hills. See: http://www.black-hills.com/shop/cowboy-ammo/45-70/

405g bullet/1250 fps.

I recently took the rifle to its maiden outdoor trip (with me) to a 300 yard range in WI.

I was about 8 inches high at 100 yards. Original front sight. Original Buffington laid flat.

But, at 200 yards, I could not hit the target--regardless of where I held the sight.

I then ran out of ammo--and my shoulder was about done, too, after being preceded by 60 rounds of .30-.30.

Is this rather-authentic load still going up at 200 yards (I understand it was originally zeroed somewhere north of 300 yards)?

Some other phenomena known to this august group but as-yet unknown to me?

Thanks in advance.