Here are my springs, the 14lb spring is on a Wolff guide rod installed in the Glock 24 slide (two views). The other picture has the slide, below that is a 12lb Wolff spring, then a 15lb Wolff spring, then the 14lb Wolff spring then the 13 lb ISMI spring. The ISMI has been used about a month in the Glock 24 and has no coils cut off. The 14lb Wolff spring is in my Glock 35 for a few months and has already taken a set, but a new one is only about an eighth of an inch or so longer.