I would be concerned about the effect of the plating on the barrel. Based on the lack of any real wear that I've seen on common nickels for over 50 years I suspect that Nickel is a metal that approaches Steel in hardness. Think about it, my Dad had a silver dollar he carried every day since returning from WWII and by 1985 it had worn to the point where it was a silver disk with some waviness on both sides. Look at a Nickel that has been carried for 50 years and you can still read the date because the impressions are still relatively crisp.

Just saying, don't plan on shooting too many of those "sliver bullets" or you may have to purchase a new barrel.