Good idea. A guitar string (the high "E") is very strong from a tensile strength point of view. Just don't get a sharp kink in it, that's the failure point.

Also, it may help to chill/freeze the powderhorn before attempting to remove the tacks. Brass has a high thermal expansion/contraction coefficient (hence the naval expression "cold enough to freeze the balls off a brass monkey" -- cannon balls, that is). This may loosen the tacks slightly.

I can slightly see inside, it looks like a piece of wood, I'm guessing maybe the plug that was in the hole at the other end.
I don't think the tacks are brass, if I scrape one its still dull black. I tried a knife blade under but just can't get enough leverage to pry them out.

If your interested, this is the rifle

Adam from Equipped2Endure carries a tiny prybar on his keychain:
https://www.youtube.com/watch?v=YPoJl7XG...ture=plpp_video

http://www.countycomm.com/titaniumwidgy.html
http://strsbackyardknifeworks.blogspot.ca/2009/09/mini-titanium-prybars.html
http://www.atwoodknives.com/home/17883984.php

Looks like you might be able to use small end cut pliers to wiggle that nail out. I would be worried that any side torquing with a pry bar type tool may cause the horn to fracture. At least with the end cut pliers, if you gently grab onto the lip on the head of the nail, there will be no side load torque and less chance of damage as you are pulling the nail directly out.

Good idear.
Diagonal cutters pulled it out. Notice the squareness of the nail to give an idea as to the age.

Glad that worked. That is nice rife you have there. Any details on the manufacturer and or the provenance of the rifle? Depending on the value of the rifle, you might not want to do any major restoration on it as it can devalue the rifle. I am not in any way, an expert on antiques but have watched the PBS Antiques Roadshow enough over the years to know about the possible negative impacts of restoration on such items.

It was made by Great Western Gun Works in PA. From what I can find it could be as new as the 1920's or as old as the 1860's.
I was in pretty rough shape when I got it. I could have cleaned it up myself but without knowing if it was safe or not. So I took it to a local gunshop who sent it out to their smith who refinished and test fired it.

Glad you got the nails out. Good job. I was surprised they were steel, but I guess at that end it doesn't matter.

Love the rifle. Lordy, do those blackpowder guns kick. Last time I fired one, my shoulder was momentarily in another time zone.

This is a small .32 caliber and a heavy rifle so it kicked about as much as a .22