You're right, Chris - it is amazing how small a load will shoot well at 25 yards - as long as a 1" group is considered good at that range. The trouble comes, as Stormrider51 notes, at 50yards and beyond. Tio shoot well out there, say 5 shots into a 1" or tighter group, even my little .32 needs 35gr. of powder as 20gr. no longer shoots well, my .40 demands I use 65gr.3F and 75gr. 3F in the .45 rifle.
Yes - they burn the powder, witnessed by producing over 2,200fps velocity along with no buildup of fouling in the bore - no wiping needed at any time for a day's shooting. Many of us here have been shooting and testing rifles for many years and also own chronographs. An interest in getting the very best out of our rifles pretty much demands it - especially for those who, like me, shoot modern wildcat rounds that have no loading data. I natrually use my chrongraph when developing loads for my muzzleloaders as well. I got my first one in 1977, so am well versed in their use in developing loads.
Too, a smoothbore will shoot a 1" group at 25 yards from a rest (or offhand with a good shot making them) - with only one sight and no rifling. Due to this, I never test at 25 yards as the results mean very little. 50 yards and beyond is where the rifle really starts to perform.