Eric with his Mauser Gewehr 1871

The Mauser 1871 was the German empire's first bolt action rifle to shoot a centerfire metalic cartridge. (This particular piece was manufactured in 1875.) The cartridge is 11.15 mm x 60mmR, and I loaded them with 75 grains of FF Goex, which I believe was the original load.
In this video, I shot the same bullet (.446 inch, 370 grains, 20 parts lead, 1 part tin) in my 1871 that I shoot in my Mauser 71/84. However, their chamber and barrel sizes are different even though they were designed for the same cartridge. My 1871 says 11.1 mm and my 71/84 says 10.95 mm, so I need to squeeze the cases down for them to chamber in the latter.
This piece seems to exhibit quite a bit of bullet drift. At 100 yards, the piece appears to shoot high and about 9 inches to the left of the point of aim. However, at 200 yards, it seems to zero out both elevation and windage wise, requiring no Kentucky windage. At 500 yards, I then have to hold at 9 o'clock, to get a square hit.
As with all my original 19th century black powder rifles, I appreciate (or frown at) all of their idiosyncrasies. I hope to learn more about how to control this truly elegant piece better in the future.
Also, I would like to extend an extra thank you to my friend Joe, whose iPhone camera work has made all of these videos possible.