Front Sight Base Barrel Diameters

AKM group..

Russian: FSB ID: .574 w/.003-.004 press fit
Chinese: FSB ID: .594 w/.003-.004 press fit
Euro pattern: FSB ID: .575w/.003-.004 press fit
Bulgarian: FSB ID: .575w/.003-.004 press fit
German: FSB ID: .575w/.003-.004press fit
Romanian: FSB ID .574w/.003-.004 press fit
Egyptian: FSB ID .574w/.003-.004 press fit
Hungarian: FSB ID .574w/.003-.004 press fit

AK 47 group

Russian Threaded: FSB ID .585-.590
Russian FSB ID .585-.590
Bulgarian FSB ID .585-.590
German FSB ID .585-.590
Yugo M-64 FSB ID .585-.590

AK-74 group

Russian: FSB ID .570-.574
Bulgarian:FSB ID .570-.574
German: FSB ID .570-.574
Romanian:FSB ID .517-.520

Krinkov group

Russian: FSB ID .551-.554
Bulgarian: FSB ID .551-.554
Yugo 7.62:FSB ID .591-.594
Yugo .223: FSB ID .591-.594

Galil ,223 FSB ID .632.