About 4-5 years ago I received a small number of bullets in a gun trade. The non-factory box is labelled: “68 gr HP Barts.” The bullets have a very small hollow point, a flat base and are 0.84” in length. The only 6mm gun I shoot is a 6BR in a Remington Xp-100 w/ a 16” barrel. I use it for prairie dog hunting and non-competitive paper shooting. I usually get about 3000 fps in the gun w/ 65-70 grain bullets. What would you do w/ these bullets--shoot prairie dogs or shoot paper?

Sounds like you have some of Bart's original flat base bullets. While I don't recall the jacket thickness I remember that they were fairly thin. Also while you won't have the expansion of a V-Max or SXHP type bullet, you should be able to center punch every PD you squeeze on - assuming your XP likes them.

Bart's make a darn fine bullet and you may be shocked at how well they group.