Have a co-worker with a reproduction Sharps rifle made by Uberti. He came to me complaining about having issues with accuracy at 100yds with the gun. I'm not much on the older black powder stuff but he is using 80g of FFF and a 425gr powerbelt projo.

He is telling me a 75yds that the gun will keep roughly a 3" group consistently but going out to 100yds the shots are all over the place and not even on the target sometimes.

My only suggestions were to try a different powder charge either up/down to see if there was a difference or to change the bullet weight up/down and see how that works.

If anyone has any suggestions or expericence I'm all ears since I'm not sure what else to recommend trying.