I've got the same peep on my sporterized Krag. Works great and was able to put 5 in the ten ring at 100 yds last week using hand loads. Not bad for 65+ year old eyes.  :o

My Krag appears to have been sporterized by a more local gunsmith. Different front sight and more wood work modifications done to the stock. There are some faint initials in the wood, and at one point it appears some numbering using gray paint was applied to the stock on the off side suggesting it was used in a club or local civilian militia, probably WWI, but that's just a guess. My dad bought it from a pawn shop around 1942, and i have a pic of him in uniform holding the Krag standing next to a deer he and his brother took.

If you're thinking about giving it a try out on the range, you may want to start by having a good look in the barrel and chamber.

Mine is in excellent condition, rivaling some of my custom barrels.  If you don't own a borescope, I'd advise getting one. They're not expensive. The Teslong is an excellent camera based borescope and is about $50 delivered from Amazon. An absolute must in my opinion.

Factory loads are still available on some shelves, usually with 168 gr soft point made by Winchester.

Mine shot best with 220 gr Hornaday RN and IMR 4350 in new Winchester brass. I also loaded some 165 gr SST's over IMR 4831SC for hunting and they shot well, but not quite as well. Some basic load tuning may fix that.

If you do shoot it, let us know your results and impressions.