We've actually had good luck with it out to 1,000 yards.
http://www.youtube.com/watch?v=HO6ihrcukcc
My first hit at 1,000 yards at a target (20" wide by 32" tall) that I could just barely see. I was smiling for weeks.
Beyond 400 the wind makes it a lot tougher and you a tang sight makes it a lot easier. At those ranges you can touch one off perfectly and the wind blows it off the target, or you guess wrong and you hit where you held hoping the wind would work with you.

We use this same target for 400, 500, 600, 800 and 1,000 yards
A few years back I didn't even know I NEEDED a 38-55. It has since become my favorite rifle cartridge. Accurate, hard hitting, economical (if you cast and reload) and just plain fun.

50 yard target

38-55 compared to a 30-30 muzzle

The Lee 379-250 recovered from sand backstop

My rifle likes them as cast - .381"