The answer to this question is fairly simple-
Can you, with any rifle you own, consistently hit a Coues-size vital organ area, at 600-750 yards? How about in a 10 mph crosswind? Maybe a 20 mph crosswind? How about uphill or downhill, say, at a 30 degree slope?
If you can pull off a killing shot, with 99 percent confidence of a clean kill, under the above conditions, then go for it.
If you can't answer this question with confidence, then don't even think about it.
Either find a new, more competent, outfitter, or just get closer.
