Does anyone know how to put the plugs ( I have both types) into the glock 27? On my other glocks they just snap in flush and tight but on the 27 one, the pierce I believe, doesn't fit the contures of the gun and the other JP? doesn't seem to fit and falls out. I have pierce +1 extensions on my mags. Do I have to modify the back strap? The guy at the gun store said "It will be good enough." Ha, good enough doesn't cut it for me so any help would be greatly appreciated. Thanks in advance for your help.