Walther FP New Board: Changing Live vs. Dry Fire Method

[Bob LeDoux]

Refer to my thread on the"Walther Free Pistol Replacement Circuit Board" for background information:

http://www.targettalk.org/viewtopic.php?t=32630

My replacement board selects live versus dry fire based on the position of the loading lever when the gun is powered up.

I received the following question:

"How hard is it to adjust the circuit logic so that it actually requires 2 pull ups on the loading lever to live fire each shot -- after the live fire mode has been selected per your present arrangement. I am thinking that most of the heavy users (ha-ha-ha, it is an addiction for some one like me) would be dry-firing a whole lot; so I would not like to have to double-stroke the loading lever for each dry fire shot. "

My response: One advantage of a microcontroller based board is such a change can be made easily in software.

The software could be changed so closing the loading lever places the gun is dry fire mode. If the lever is raised slightly and then closed again within a short period, say one second, the gun would go into live fire mode.

But, once in dry fire mode you couldn't go back to dry fire without discharging the cartridge, or waiting a bit of time. This is because the circuit, once charged to live fire voltage, takes about 30 seconds to discharge back to dry fire voltage, after the loading lever is opened.

I tested this scenario: The shooter loads a fresh cartridge, closes the chamber and then decides to dry fire. The shooter proceeds to dry fire several shots by pulling the trigger, lifting and closing the loading lever and again pulling the trigger.

To make the dry fire "click" the firing pin is lightly tapping on the live cartridge. I tried the dry fire routine on a live cartridge in my Walther. After 12 dry fire "shots" I examined the cartridge. I could see no sign where the firing pin had indented the cartridge.

One proposed software option would eliminate the initial live or dry fire selection made by loading lever position on power up. Instead, the selection of live or dry fire could be made at each shot.

This could be the beginning of a menu of options so the shooter selects the software to meet individual needs.

This type of change could be made to other air and free pistols that utilize electronic triggers.