LampShadeActual
05-12-2012, 04:34 PM
Slide hold open lever spring. As an item to watch out for with a Kahr CW9, the slide hold open lever spring may need tweaked to prevent the slightest inadvertent contact from locking the slide back while there are still rounds in the magazine.
There is info somewhere around here about how to tighten the slide hold open lever spring screw some magical amount and be careful not to strip it and if you do use super glue and if you do it right it makes the spring operate like two springs. One part against the take down pin and the other pressing the slide stop lever down.
My opinion is that the above advice is faulty. Tightness of that screw has nothing to do with how the spring works. Making it so tight it works as two springs messes up the factory design.
The spring and washer keep the spring from falling out. That is all they are supposed to do.
My opinion based on Mk.1 Mod.0 eyeball examination and watching function is this. The proper function of the spring is in parts:
a) At about 1:00 viewed from the left side of the frame there is a pin on the end of the spring that inserts into the frame. The pin locates the spring.
b) The spring winds counter clockwise so that the 9:00 loop presses against the take down pin for a pivot point and to drop into a notch in the take down pin so the pin stays in.
c) Underneath the screw washer, hollow side up, the washer and screw prevent the spring from falling out and trap it in the slot provided at 6:00. The spring is intended to be free to move in this area. The screw and washer only need to be slightly snug to perform their function and NOT interfere with the free movement of the spring.
d) The spring continues to wind up so that at about 3:00 it makes a turn to the right/rear of the frame. The part after this right turn presses down on the slide stop.
On my CW9, there is/now was so little tension with the projection at 3:00 that the slightest touch knocked it up into slide lock open.
Fix in relation to function of the spring: Remove the screw, washer, and spring. If the 6:00 position of the spring is grasped by a set of small needle nose pliers and the projection is grasped with a second set of needlenose pliers and if the projection is turned ever so slightly so that it orients to 4:00 instead of 3:00, you have "fixed" it. The two sets of pliers would be oriented the same way your eyes look at the spring assembled from the side.
With the end of the projection now at 4:00 there is perhaps twice to three times the tension down on the slide stop. When installing the slide stop, you now need to be careful to wiggle it so the spring projection climbs up over its contact point on the slide stop lever. The spring projection then drops/clicks into a little groove that keeps the slide stop lever in place. The 9:00 loop also drops into the groove in the takedown pin.
This small change appears permanent in the spring and keeps a slight bump from activating the hold open feature. The spring now has more tension on the lever and the spring is free to flex through and under the washer at the 6:00 position as its design intended. With this fix there is NO STRESS on the spring screw or washer and you don't strip it which means you need a new frame.
If the bottom corner of the slide hold open lever, the flat part with the little grooves, is rounded under and polished so the last groove disappears, about a 45 degree bevel, but not all the way through the metal at the bottom underneath side, it also reduces the tendency to self activate. This is because the corner is gone and it is now a bevel instead of a square corner. You can thin the bottom inside as long as you don't cut clear through to the inside.
It makes a neat looking job if you use 600 grit to cut it and 1500 grit to polish it. Wrap several layers around a popsicle stick and you will not FUBAR as you remove metal.
There is info somewhere around here about how to tighten the slide hold open lever spring screw some magical amount and be careful not to strip it and if you do use super glue and if you do it right it makes the spring operate like two springs. One part against the take down pin and the other pressing the slide stop lever down.
My opinion is that the above advice is faulty. Tightness of that screw has nothing to do with how the spring works. Making it so tight it works as two springs messes up the factory design.
The spring and washer keep the spring from falling out. That is all they are supposed to do.
My opinion based on Mk.1 Mod.0 eyeball examination and watching function is this. The proper function of the spring is in parts:
a) At about 1:00 viewed from the left side of the frame there is a pin on the end of the spring that inserts into the frame. The pin locates the spring.
b) The spring winds counter clockwise so that the 9:00 loop presses against the take down pin for a pivot point and to drop into a notch in the take down pin so the pin stays in.
c) Underneath the screw washer, hollow side up, the washer and screw prevent the spring from falling out and trap it in the slot provided at 6:00. The spring is intended to be free to move in this area. The screw and washer only need to be slightly snug to perform their function and NOT interfere with the free movement of the spring.
d) The spring continues to wind up so that at about 3:00 it makes a turn to the right/rear of the frame. The part after this right turn presses down on the slide stop.
On my CW9, there is/now was so little tension with the projection at 3:00 that the slightest touch knocked it up into slide lock open.
Fix in relation to function of the spring: Remove the screw, washer, and spring. If the 6:00 position of the spring is grasped by a set of small needle nose pliers and the projection is grasped with a second set of needlenose pliers and if the projection is turned ever so slightly so that it orients to 4:00 instead of 3:00, you have "fixed" it. The two sets of pliers would be oriented the same way your eyes look at the spring assembled from the side.
With the end of the projection now at 4:00 there is perhaps twice to three times the tension down on the slide stop. When installing the slide stop, you now need to be careful to wiggle it so the spring projection climbs up over its contact point on the slide stop lever. The spring projection then drops/clicks into a little groove that keeps the slide stop lever in place. The 9:00 loop also drops into the groove in the takedown pin.
This small change appears permanent in the spring and keeps a slight bump from activating the hold open feature. The spring now has more tension on the lever and the spring is free to flex through and under the washer at the 6:00 position as its design intended. With this fix there is NO STRESS on the spring screw or washer and you don't strip it which means you need a new frame.
If the bottom corner of the slide hold open lever, the flat part with the little grooves, is rounded under and polished so the last groove disappears, about a 45 degree bevel, but not all the way through the metal at the bottom underneath side, it also reduces the tendency to self activate. This is because the corner is gone and it is now a bevel instead of a square corner. You can thin the bottom inside as long as you don't cut clear through to the inside.
It makes a neat looking job if you use 600 grit to cut it and 1500 grit to polish it. Wrap several layers around a popsicle stick and you will not FUBAR as you remove metal.