Point 'em in the direction ya want the bullet to go an pull the trigger
All in jest, of course!
Every gun is a 'cat in a bag', especially used. For that price Id probably buy it (and Im.....frugal), but its always good to check the lock up and look down a barrel, etc. If a muzzle loader I take my rod and patches and some WD-40; lube a snuggish fitting patch with the WD and run it slowly and carefully downbore and out, check the condition & color of the patch for rust and crud. If still OK run another one down and 'feel' for bad, snaggy spots where some rot might have got to it. On the H&R you should(?) be able to pull the breechplug fairly easy to eyeball it.