The choke is a way of narrowing the barrel. It is designed to keep the shot in a tighter pattern. A full choke is supposed to increase the effective range of the weapon.
Yes chokes are designed to tighten shot patterns.
Break open the action and it should be engraved on the metal that is normally unseen when the action is close, that or it should be on the barrel. If the chokes are removable then it should be engraved on those as well.
There is an excellent article at the link below to explain the choke process for shotguns.
Yes, they describe the various chokes.
Best guess: You have a shotgun manufactured in Croatia. "Pun" means "Full" in Croatian. "Pola" means "Half". You would have something like 70% constriction in the Pun barrel and 55 to 60% constriction in the Pola barrel.
The choke on a shotgun "chokes" the end of the barrel, compressing your shot. Therefore creating a tighter pattern. Kind of like a nozzle on a hose. If you turn it on without a nozzle it will come out thick and not go very far, put a fine tipped nozzle on and the water will stay together and travel farther. Hope this helps.
The Invector, or "Standard Invector" system" was introduced in 1983. A few years later, the Invector-Plus chokes were introduced to fit the new back-bored shotgun barrels. These two choke systems will not interchange. If you have screw-in chokes in your shotgun barrel, the kind of system you have will be stamped on the barrel near the receiver. You must use the proper choke system for your shotgun.
only if your choke is improved cylinder or modified, full chokes are a no,no. the barrel will bulge or burst!
It's called a choke, and restricts the bore a few hundredths of an inch. Most are round, for hunting, but there are some called "duckbills" that spread the shot laterally for combat purposes, though they're not popular anymore because they didn't offer a significant advantage. There are fixed chokes, permanently part of the barrel. There are adjustable chokes, which turn to constrict. There are removable chokes, which set in place with a wrench.
By opening up or constricting.
Modified.
Either. In general, slugs can be fired through any standard shotgun barrel. An exception is for Extra Full Chokes, which are not standard. Best accuracy with slugs in probably modified choke.