Detect rifle shot

Well, once again, that raises the question - is it this guy's own gun, or does he run a shooting range?

Howcome he can't keep logs of how many bullets have gone through a given rifle? Like, when you issue a gun (at the gun club), log in what ammo they're going to shoot, or if it's his own gun, just write it down when he buys a box of bullets.

Thanks, Rich

That's why I suggested taking ten percent off the mfgr's stated life expectancy to get a ballpark of when to check it physically. Or he could just do it after say every few dozen boxes or so.

Mark L. Fergerson

easiest, and somewhat imperfect is to stick a mechanical counter behind the bolt.

it could be made fairly easily, actually a small electro mechanical relay could probably do what you want if oriented correctly. but you don't need the coil just the contacts.

possibly a ceramic grammophone cartridge, or a "crystal" earpiece, one of those disc speakers may put out too much voltage...

I'm thinking something like this. ____ +----------> shot | +V -[1M]---+--+-----v spring contact, close but not touching. | 10n === .-----^ fixed contact point | | gnd -------+--'  || || direction of barrel \||/ \/ the hard bit will be arranging it so that firing the rifle brings the contacts together and other shocks in the same direction dont.

Bye. Jasen

those shocks should be in the opposite direction to the one when it's fired.

like a switch activated by the bolt ...

interfacing with the safety could save the battery too... but these ideas are invasive....

that depends how long it takes for the processor to awaken.

vibration, but ideally a passive sensor is needed.

possibly a piezo element driving a charge pump that fills a metering capacitor.

.--+-->|----+-/\\/\\-+--> shot | _| | | \\ |(_) `-| GND

Bye. Jasen

So, what you really want to do is put a sensor on the barrel that 'listens' to the bullet go down it. Then you record and FFT the answer and cross correlate it to a known good bullet down a known good barrel. When the mismatch becomes enough it's time to change the barrel.

So, rather than putting the electronics on the rifle you put the sensor on it and you sell the shooter a 'hipbox' so every so often they can plug it up, fire off a few shots and get a profile of how the barrel is doing.

DNA

But the gun barrel is unterminated, wont you get nasty reflections?

martin

"Genome" schreef in bericht news:wA7Bg.13575$ snipped-for-privacy@newsfe2-gui.ntli.net...

Don't forget to compensate for temperature, humidity, air pressure and angle of the barrel.

Details, details.....

I think you'll find the barrel is nicely terminated until the bullet leaves the end.

DNA

Did I not say 'cross correlate'?

DNA

Don't you mean the US Dumbland Security Dept have just sent round the Heavies, and told you to shut up?

martin

Gosh!, sorry. I really wasn't thinking. Shit :-(

Good job I've got that spare tube of heatsink compound :-)

DNA

Dont worry, Gitmo is easy to escape from during the hurricane season, just do yer normal MacGyver stuff and Cuba is looking for a new leader

martin

If you shoot a lot and have several guns of the same caliber that probably won't work but I do agree with the other poster, measuring the bore erosion is a better indication of wear than simply counting shots. Different loads and bullets will have varying effects on wear.