What is a quick and easy way to determine the cylinder to use for an extended barrel? Refer to the barrel length table below. If, let’s say, you want your MP5K to use a 229~230mm inner barrel, then simply put in a cylinder for the MP5 A4 model.
110 mm – used by MP5K
141 mm – used by MP5KPDW
229 mm – used by MP5A4/A5/SD5/SD6
245 mm – used by UZI
247 mm – used by CAR15, P90, G36C, SIG552, AK B-S
285 mm – used by MC51
300 mm – used by Thompson, M733
363 mm – used by M4/RIS, SR16, XM177, SIG551
369 mm – used by HK51
455 mm – used by AK47, AK47S
469 mm – used by G3A3/A4/SG1
472 mm – used by FAMAS
509 mm – used by M16A1/A2/VN, AUG
534 mm – used by SIG550
590 mm – used by PSG-1
Keep in mind, if you are not using a very long inner barrel you should not need to change the stock cylinder. A hole on the cylinder for intentional air leakage is good for short barrel setup as it allows the piston to get pushed back faster without disrupting air volume balance.
