All Divisions compete together on the same stages and on the same days in a match, however, when calculating match standings, only Divisional stage scores are compared. Thus, the top shooter in Open on a stage is the measure for all other Open shooters, and likewise for all other Divisions. More information can be found in the IPSC Shotgun rulebook. There are 4 divisions currently recognized in IPSC Shotgun Competition:
Open Division is the shotgun equivalent of top fuel dragsters. The guns have compensators, optical or electronic sights, and almost all now feature detachable box magazines. There is a ten round limit when loading magazines so a loaded chamber start means 11 rounds for box fed guns.
Modified Division Modified guns can have almost all the same features as Open guns with the exception of detachable box magazines, meaning these guns are tube fed and do not have a load limit but there is an overall length restriction of 1320mm. Yes, you can run a comp on the barrel and use a red dot sight. USPSA does not use a box to measure the overall length while IPSC does so keep this in mind before traveling.
Standard Division guns are tube fed guns but unlike Modified, optical or electronic sights and compensators are not permitted. They have an initial load limitation of 9 rounds but interestingly no overall length limit.
Standard Manual is similar to Standard except the guns are not self-loading, which in practice means pump actions, although under-lever or even double barreled qualify for this division.
