Here are a few statistics you might find interesting.
There are about 1.5 million people in all branches of the American military put together. The majority are unarmed noncombatant support staff.
Between one-third and one-half of American adults own guns. Some only have one, but the average number is eight guns. About half of non-gun owners would be willing to own a gun in the future.
Even if we go with the more conservative estimates and assume that only a tenth would fight, armed civilians would outnumber the military two-to-one. And because this is a point that bears repeating, most people in the military don't actually fight.
...You know those weapons are basically fucking cap guns compared to actual military hardware,
right? This isn't 1782, where the best anyone could hope for was a flintlock musket. The military (hell, even SWAT teams) have an
enormous technological advantage against Joe Scumfuck that thinks his .223 Remington hunting rifle can stand toe-to-toe with assault rifles, submachine guns, and squad automatic weapons like the M249 SAW.
That also completely discounts the extreme amount of training and experience even your average Army grunt has over John Q. Gunlicker who, most of the time, could just about run thru the woods at his auntie's house in Sisterfist, Arkansas and
maybe hit a can with his illegally modified AR-15.
Again, even against a comparatively tame SWAT team, most of these LARPing dipshits would last about half an hour before either being arrested or ventilated. Sure, you'd have a few ex-military holdouts here and there, but its exceedingly unlikely they're the second coming of Simo Haeyhae. Most of 'em are Frank Castle wannabes that, again, would eventually either be forced to eat turf and get yeeted behind steel bars for the rest of their lives, or cornered in whatever backwoods trailer they made their home and turned into pincoushins.