Here are some things to consider and ponder. Higgins opperated at Indian Springs under treaty with the Creek Indians this was around 1820. Going back a few years to say 1800, Ben Hawkins Indian Agent, recruited a number of gunsmiths to work at the trading houses throughout indian territory. This was prior to The Creek War of 1813-1814.
The trading house for the Choctaw at Fort Stoddart Mississippi Territory " later Alabama" in 1805 reported smooth bore arms were virtually unsaleable to the Choctaw Indians. The Choctaw wanted rifles.
It is safe to assume that the other tribes were the same. Many Cherokee Chiefs were bribed for land by fine rifles and cash. So it would seem the further west you go or the closer to the NDNs or mountains you get, the closer you are to rifle country.
In the coastal areas from the Tidewater Virginia area to Savannah was a heavy smoothbore or fowler culture. This area would be heavily influenced by England. As a matter of fact that area was England until 1783. So the coastal areas were smooth bore or fowler country.
For decades the port of Charleston imported smoothbores by the crate load. The early English trade gun has been nicknamed the Carolina Gun. It is also known as the Type G. This was in the years prior to the Revolution but a few of these have been found converted to percussion so it is safe to assume a few of these were still in use in the first 2 decades of the 19th Century.
Here are some more things to make it clear as mud.
A early sketch of a 1810ish GA squatter on Creek land shows the fellow resting on what appears to be a slim long barreled fowler. Sam Dale hero of the Canoe Fight on the Alabama River in 1813 was known for his double smoothbore. Wether this was a classic side by side or some sort of double musket is unknown. A double gun was unusual at that place and time.
Evidence from the Fort Mims Massacre site shows a few rifles from 34 to 54 caliber most being around .45. What is suprising is the large number of shot from the. 20s to around .32 and virtually no musket sized ball. So it looks as if the muskets which it is known were there were being loaded like shot guns by both Indians and Americans.
Spanish influence was heavy in this region as the Floridas were Spanish Territory until 1816. This region also has a lot of French influence.
Gen. Coffee's Tennesseans at New Orleans were armed with rifles and guns. Guns being smooth bores, possibly smooth rifles.
For a Georgian in 1820 he could have a fine English or American fowler made in the English style. The poorer he is he could have an old trade gun English French or Spanish, maybe a restock. Closer to the frontier he could have a Smoothrifle. If he is native he could have a Third Model Brown Bess or Spanish Musket supplied from Florida durring the War of 1812.
From a rifle maker like Higgins, most likely a Smoothbore that handles like a rifle... a smoothrifle.