Edvin

So I've been messing around with making a digital ammo counter for my LS. Currently it's in initial phase, and I am still working with big, cheap, and power draining transistors (can't just slap a battery on there just yet). This requires a little bit of electronic works: Any comments would be greatly appreciated.
Display:
The key here is a 74193 up-down binary counter. This baby works like a charm because you can preload the number to start counting from anything below 15. Naturally I went for 6, and it counts down on every rising edge clock signal.
To prevent digit rolling over after it reaches 0, because you wouldn't want to think you have 15 darts left after you fired 6 shots, I connected all the outputs to AND gates (7408 quad AND gate), and link the output back to the CLR of the 74193. And voila, as soon as the signal reach 0 (0000), the bugger rolls over to 15 (1111), and the whole thing is cleared back to 0 again.
The magazine release switch will load the counter back to 6 again.

Countdown trigger
This part is a little tricky, and I can't really find a way to do it just yet. I'm thinking of using a chain of FF switches with 2 triggers--from the cocking action, and then the pulling trigger. However, I haven't had time to think about this yet.

Loaded chamber indicator
I will be using a 1.5 digit display, which means I will have the decimal dot left unused. I'm thinking I might use the dot to display a cocked and loaded gun, since I will probably place the display right over the "loaded slot" of the gun (which turns orange after the gun is cocked.)

Now here is the big question:
I am a lowly electronics student and have barely any experience in the field--what transistors/displays should I use to keep power consumption low enough to stay on a AA or AAA batteries?

If I do anyone is interested, I will post a circuit diagram later.


**this will be the first step to my larger LS mod, which will include converting it to pump action Nerf, with the slide and connections being fitted within the gun rather than just connecting to the old cocking device.