Friday, March 06, 2015

I don't THINK so!

Magnetospeed: Obsoleting Convenional Chronographs - The Firearm Blog: Magnetospeed: Obsoleting Convenional Chronographs

Oh, that's so ... new!

So we now have a magneto-powered chronograph.  I'm so pleased.
 (What does 'magneto' mean?  sensors are rekatubg the framamjig instead of dependent on impinging light sources.  Now you know as much about it as I do.)

I do love high tech, but I gotta couple of  (okay, 3) questions:

(1)   What are the most common usages of chronographs?  I mean, in terms of number of guns/rounds per time?  Answer:  at major shooting matches where "power factor" is part of the equation, it's used to determine whether the gun is "Major Power" or "Minor Power".
(2)  How long does it take to install the thingamajig on each gun, and just how MUCH difference does it make how much difference the "... sensitivity to placement... " makes in determining the accuracy of readings ... especially when comparing one firearm to the next.
(3)  What happens when you're using the magnetospeed thingie to chronograph a compensated race pistol?

I've used 'conventional" (dependent on light source) chronographs a bit.  I even helped run the Chrono stage at the Area 1 USPSA match a few years ago at ARPC in Oregon.

The thing is, I think the greatest VOLUME of Chrongraph readings occur at competition matches, where "power factor" must be determined for each individual firearm.

Using the light-sensor style of Chronograph is problematical because (as the article states):

Conventional chronographs work by measuring the time it takes for a bullet to pass over two optical sensors. The problem with the conventional approach is that ambient sunlight affects the velocity reading. Other problems with conventional chronos is that they are big and bulky, require a tripod, need long cables and risk being destroyed by your bullets or shotgun wads.
I think that the implications inherent in that statement are perhaps applicable for the individual, but at a Major Match?  It's all bullshit.   I don't THINK so!

Most Major Matches address that problem by using a 'light box', where the ambient light source (the sun) is blocked off; illumination sources are inherent in the 'tunnel' with two chronographs and two paired artificial light sources are included in each light box.  A chronograph sensor array is included in each light box, and the chronograph technicians use a consistent algorithm, usually involving using the mean, median, or highest velocity recorded for each shot through the light boxes.

This arrangement means that each shot fired through the light box is subject to exactly the same illumination, so multiple shots from multiple sources (firearms) are reliably compared to each other.

The problems inherent in this arrangement, according to the article, are dependent on inconvenience of setting up a system which will equitably and reliably record projectile velocity, the need to use hard-wired cabling (not necessarily true with ALL light-source systems), and the possibility that you'll shoot holes in your sensor arrays.

I'm not that good a shot, but in 1-1/2 days of the match I shot over 300 pistols (about 1,000 rounds) through that light box with zer failures due to I shot up the damn sensors!   It's not that hard to do.

And the equipment was the single standard which we KNEW was consistently analyzing the data from shot to shot, and from firearm to firearm.  We set it up, it worked, and it kept on doing it's Energizer Bunny impression for the duration of the match.  There were some tears when folks discovered their ammo/pistol combination was not returning the same results as their tests Back home, but everybody who shoots Competiton has suffered the Chrono Blues from time to time.  Why?  Because the Chronographs are accurate, for that date/time/atmospheric conditions etc.

Consistent Testing Environment:
However, if we were using the Magnetrometer Chronograph, we would always be fielding complaints that we were not providing an equitable testing environment.  Why?  Because the sensors must be installed on each firearm, and every firearm is different!

The Magnetospeed is a good device – of course you have to watch placement. 
I gather that means that they way you install the device on the barrel of the firearm has a significant effect on the velocity recorded.

And in a match ... how do you compare oranges to apples?

(okay, not 100?, but generally speaking ... how do you rate a Production pistol against a compensated Open Pistol?  Or even two Open Pistols, when the compensators have a different configuration?  Those race guns, they're like cheating, y'know?  You can do anything you want to with the barrels and comps, and who knows how the compensator designs are going to compare when evaluated by the Magento-Man Sensor Arrays?)

Oh .. well, the arrays would probably be destroyed long before the match is over. 

 Attach to the barrel of the gun?

I don't THINK so!

This stuff is fine in it's place, which is the individual, testing of bullseye or varmint (or even some hunting guns) where you're trying to develop a load and you want to test only ONE FIREARM!  

And even then, if you don't put the sensors in exactly the same place for every test, or the configuration of the barrel is different .. how do you know that the down-range effects are going to reflect the point-of-the-barrel measurements?

I THINK that the only way to measure the velocity of a bullet down-range is to measure it down-range.
Oh .. did I mention the question about how barrel vibration affects the sensors?  No? 

Consider it mentioned.

But, that's just me.

I'm just an ageing Geek, so what do I know?


Anonymous said...

I haven't gone off on the unicorn-world shooting rulz you use in your matches for a while, Sir Geek,but I am going to DESTROY this entire system of yours with two words: FACTORY AMMO.

Instead of major & minor power factor, use major & minor caliber, and issue the damn ammo. Your form of shooting competition is supposed to be about speed and accuracy attained within standard safety perameters (some of which are also idiotic IMHO). Wouldn't the match be a better test of shooting ability with a more exact standard? I propose a system where you bring your gun of choice in one of two standard calibers for each category, pistol or revolver. I suggest 9mm 115-gr ball and 45ACP 230-gr ball for pistols, and 38 Special 130-gr FMJ & .357 Magnum 158-gr FMJ for revolvers. Ammo to be issued. No personal ammo on range.

BTW, guess what this competion most closely resembles? Yep, police "shoot village" training! Good thing about Shoot Village shooting is that you can practice the exact course in a simulator.


Anonymous said...

The MUST be the answer to the Chronoman's prayer. The preferred alternative is outlined by Mr. Rivrdog, above.

Anonymous said...

Modern technology is great.