Does the 17" bbl on the 21 make the cyclic rate on a 21 run faster than if you had a 21" bbl?
just swap out. when cleaning the gun it's easy..(check your gap before running the gun!)after you swap out parts!Intersting. I have #9 locking piece installed in my RTDS HK21 and Ralph told me that it is slower than a #17. Is the #9 the standard 21 locking piece?
Also, Ralph mentioned that the locking piece is a Pain in the @$%# to change. Do you have any tips on doing this?
Sorry for the delayed reply...Ryan
Did you ever perform any measurements or have any guess as to how much the ROF was reduced by using the 17 unit?