I was searching and tried to find Croatian made firearms like Agram 2000 submachine gun manual,Gepard M2,M3 and Lynx GM6 manuals but no available anywhere....I tried type Croatian language it also give me no information....
Some firearms manuals are so hard to obtain,Ruger MP9 one of them,Hotchkiss Universal are another forgotten artifact,as for shotgun series most unique and unusual from my taste is Jackhammer MK3A1 developed by Pancor,a prototype that never went into serial production but was consider as Assault Combat Shotgun or ACS for short....The idea was creating new select fire shotgun for law enforcement agency to replace older models like Remington or Mosberg,however idea was never work,Jackhammer had complicated cylinder extraction method to reload and based on Webley Fosbery operation with gas stroke mechanism to actuate cylinder rotation,half revolver and shotgun combined but capable operate at automatic firing....From my own study it should inquire pivoting hinge pin with lever that retains cylinder and allow quick removal rather than taking rear stock apart to gain access for that pin.In this point cocking handle should move forward not back like conventional firearms,this would disengage carrier from cylinder groove so it can separate from receiver.
Very unique automatic shotgun design,too sad it wasn't went far rather than been a prop gun in movies as 1st model,2nd end up else where but only 2 or 3 of them where made,2nd MK3A1 so called improved variant never even been introduced after designer decided to scrap whole project just like Bill Ruger scrapped his MP9 design sadly,if Ruger MP9 get fixed 3 issues it would most likely adopted,as it was feature simple design.
There is 3 known issues that cost failure with Ruger MP9:
First issue was most obvious welded ejector at upper receiver housing which already a no go design,in numerous firearms ejector pivoted by retaining pin,like Walther G43 Gewehr,in Steyr Hahn pistol ejector retains by trigger bar,ejector serves as disconnector at same time and spring loaded,there many examples that ejector is pin retained for easy and quick access and replacement if necessary.
The 2nd issue was most iconic,ball and spring loaded cocking handle which supposed to work and hold bolt back when every round fired from magazine but it works at entirely opposite scenario,bolt stop works when last round remains in magazine.
Third issue was complains about stock design,which at some critics was far worst than original UZI design....
The Ruger MP9 have nothing to do with entire submachine gun design,it was originally Uziel Gal engineering like UZI,open bolt design lead to close bolt design and originally was known as model 201,however he gave entire development to Bill Ruger so he could finish additional safety installation for firing pin,like many of his designs.This would explain why Ruger MP9 have 2 bolt components unlike original UZI design,this was done to allow installing firing pin safety,there is an lever inside trigger mechanism housing when bolt closes breech firing pin safety and release lever aligned and allow to be released.There is 2 sears like many submachine guns out there but position of them opposite,auto sear located at left side and locked with trigger bar,semi auto sear at right side and locked with disconnector identical like in Ruger MK1 or MK2 pistols,not sure why disconnector even been added for while other closed bolt submachine guns absent of that component...
