I have been shopping for a krag barrel .. And they say dark bore .. I have no idea what this means ... I purchase a lot of guns and restore and resell them so the worse condition there in the happier I am .. Because you can get them cheep cheep and sell them hi hi ... So quite often there so durty you can't even see down the bore ... So I clean them and sometimes there still very dark inside .. So get my shotgun cleaning rod and swabe and but the rod in my drill place polishing compound on the swabe and polish the cartridge camber until it looks like a mirror inside ... And then I get my bore swabe and put polish on it and turn it inside the bore with my drill ... Some times it still dark so I get a new swabe and use diamond polishing compound and so up and down though the bore until it shines like a mirror ... Diamond dust comes in 400 to 50k grit .. And also there is a lot of metal polishing compounds you can get at Walmart ...  I always found it helps to have a nice shinny bore when you sell a gun ... What I have found is a shiny bore don't make you a better shot its just a marketing skeem ... Drak bores shoot just a good ....

My concern over dark would be the corrosive pitting.  Ha, what lies in the dark!
Vic

I am a "bore" critic and have used a wonderful Hawkeye bore scope for years to closely examine firearms to determine the state of the bore and my cleaning progress. Simply looking down a bore at a light or with a bore light can frequently give false appearances of the real quality of the bore as when examined with a scope.

I have seen much damage done by overzealous cleaning. I would easily turn down a "mirror" bore or chamber that appears to have been cleaned improperly or polished to make an easier sale. I love getting a darker, dirty bore that I spend an hour or more cleaning well to have a great hidden bore reveal itself. I carefully use a new brass brush at times but I almost never polish with abrasives. As butler says above, many of us have found that even a dark, pitted bore can shoot quite well in an older rifle.

But, many uneducated and unaware buyers will be attracted to a shiny bore. Many are also attracted to a freshly cold blued barrel or a nice, shiny varnished stock.

So please limit your over polishing of your rifle bores. Once damaged, these bores cannot be restored to their original condition. It definitely will lower the true collector's value.

I have been quite surprised at how many of the Krags I have gotten with horrible bores actually clean up really nice. I have a couple terribly pitted bores on nice outwardly appearing Krags and some wonderfully preserved bores on M1894 and M1896 Krags. That ammo back then was really corrosive!

I am one of the few weirdos who loves cleaning my firearms and bores but I detest over cleaning and "polishing" for looks only. I do believe in doing what we can to preserve the history and be good stewards of the classic military firearms that we are temporary owners of. The future generation of collectors who will be next in line to enjoy all of our Krags will certainly appreciate all that we do now to keep our Krags as original and correct as possible.

Afterall, the number of original military correct Krags will only go down as time proceeds! Especially when they are mis-handled, abused and dis-assembled and sold for parts.

The bore in my Krag did not look good when I bought it. I used a bench rest shooters cleaning method, and found a very good bore, which shoots very accurately. The cleaning method uses Krill oil, and JB's bore cleaning compound. I use it on all used rifles I buy, and it does an excellent job.

I shoot 17 Remington and get copper fouling in the barrel ... Its so fast the friction melts the copper ... Anyway what I use is Montana X-Treme bore conditioner and it works very well ...

The old method, shockingly, would involve plugging the chamber with a cork or rubber block of some sort and filling the bore from the muzzle with mercury. Leave it in overnight and it would amalgamate with all of the lead in the bore and clean it right out. This method actually is one of the best and easiest ways to clean the bore of deep and compressed lead. Of course, we don't use mercury for this purpose anymore because of it's toxicity but what a great solution to a leaded bore!

I have lots of mercury and, as a former chemist, have experimented and played with it carefully. Even taught my kids, safely, about the amazing properties of this metal. I have never used it in a bore, though. Too easy to lose some of it and contaminate something (like me.)

So, now we use bore brushes, chemicals and brass screens to pull through the bore to get the lead out. Or, as some do regularly, shoot a few full jacketed bullets through the bore to clean the lead out.

Kroil is nice and one solvent/lubricant I use at times. I love Sharp Shooter's Patch Out/ Wipe Out which can be combined with their Accelerator solution. Brownell's sells these. This will quickly pull out copper from a barrel as well as deep carbon and lead. Amazing to see the patches come out dark blue with copper when I use these products.

But, everyone has their fav. I use some Hoppes but there are better chemicals.