You will need a gunsmith.
Yes
H&R and I believe Rossi have single shot rifles with interchangible barrels.
TC is one
You will have to define who "they" is.
Rifling in the barrels
Ease of manufacture
NoThis is from the Winchester Website:How versatile are the Model 1300 barrels? Will they fit earlier or different models?The Model 1300 barrels will fit Model 1200 receivers, but 1200 barrels will not fit a Model 1300. Model 1400 barrels will not interchange with Models 1200 or 1300 barrels.The Model 1300 Defender barrels will not interchange with the 1300 Field models and viceversa.
Check gunbroker. There's an info packet for sale telling all about 219, 219B, 219L The 219B was made after WWll until 1963. In ex. cond. it's worth 7-8 hundred. In poor cond., $125 - 250.
marlin made 1993 rifles and 1889 rifles, barrels are about $75 if good, the rifles are about $250 to $500 , all calibers are about equal.
rifle barrels may have a different external diameter. A rifle that is carried for hunting will usually have a "sporter" barrel- slender, to save weight. Target rifles will have more massive, stiffer barrels for accuracy. Those are "heavy" barreled rifles.
No. HBAR is an acronym forHeavy Barrel. Also, referred to as a bull barrel. These are common barrels used in match or competition model rifles.
If the owner's manual doesn't tell you, you need to contact the maker.