Keith,
Good to hear from you again!
As a former Warrensburger, I pondered that myself. For one thing, John's mom was a merchant according to the 1860 census, so that may be part of the explanation.
I hadn't thought of the Liberty arsenal, but the southerners seized everything in it when they took that place in 1861. I seem to recall from my reading that they took a number of shoulder arms, but I don't recall reading that they obtained much powder there. Could have, though.
Yes, it's very likely those 125 kegs probably came from that huge batch at Jefferson City in June 1861. The Brinkers or somebody would have had to bring all those heavy kegs down from the Missouri River over a county away to the north in wagons, unless southerners brought it directly from Jeff City along the roads. Either way would have been better than boating the powder west on the Osage River and bringing the shipment by wagon northwest across a county or two. The railroad wasn't built much west of Tipton about two counties to the east then, and the southerners wouldn't have shipped that powder in such an open manner, either, with all the boat crew and passengers wondering where it came from and where it was going.
Bruce Nichols