The 8mm Mauser is certainly a viable hunting cartridge, with ballistics that parallel .30-06 with proper loading. Though I've yet to hunt with mine, I'm planning to this fall, perhaps.
Accuracy on many of the nicer surplus rifles really isn't bad either, and is certainly well within the acceptable range for most hunting applications! I just recently started handloading for my M-48 Yugoslavian Mauser, and ran some tests on 175 grain Sierra Pro Hunter bullets (spitzer soft-points). When I shot these loads I was using the original (unadjusted) open sights, from a prone sandbag rest at
just shy of 100 yards (I believe I measured the range at 89 or 91 yards that day, IIRC).
I shot seven 3-shot strings during this initial test, with loads ranging from the "starting" charge for H-380 powder to a "maximum" load. The average for all of these groups ended up at 1.77" center-to-center, with my best 3-shot group at 0.77", and the second best group at 1" even! The worst group I shot that day was a 3.7" group, which was very likely caused by pilot error resulting in a flinger. Needless to say, for a cheap surplus rifle, with open sights, and me shooting it... Well, I was pretty darn happy! If I can have a repeat performance on my next range trip, I'll really be thrilled
If this picture attaches correctly, here is one of the groups I shot that day (the actual aiming point was just below where I cropped on this picture... without trying to calculate the ballistics, I'd say the factory elevation setting is about right, given that the issued sights start at 200m, and I was shooting from around 100 yrds. Thus, the POI was a bit high). Keep in mind that the true capability of the rifle itself is probably not even reflected in these groups... I was shooting with the original sights on the rifle, rather than upgraded sights or optics.