Armory Sponsor
Posted: 4/8/2012 2:26:09 PM EDT
|
I've never use a chronoghraph. They look a bit complex and overwhelming. I've been doing a fair amount of internet research on chronographs and have come to the conclusion that all of them are about the same, except that the more you spend gets a bit more accuracy.
Then I saw the Magnetospeed chronograph at Magnetospeed.com. Different to say the least. It straps onto the barrel and uses electomagnetic field interference to measure speed. Nothing optical. Looks like a bayonet. I am seriously considering purchasing one, especially for developing loads with surplus powders. Does anybody have any experience with this new fangled contraption? |
|
I saw the web page for that chronograph for the first time on Friday.
I like the idea, but for the price won't be an early adopter. I might as well tell you my opinion about your plan - you'll never, ever, measure pressure with a chronograph. A chronograph measures bullet speed. A chronograph can serve as an aid to understanding the pressure your gun and loads produce in a qualitative sense, such as loads that produce erratic velocities. But to use it to work up loads as the primary measure of pressure by watching the speed produced is useless. Especially when using surplus gunpowders with no prevenance and no knowledge of the gunpowder's character from lot to lot. |
| No, sir. I will still use the traditional pressure signs; watching the primers, primer pockets, and brass growth, etc. Just curious about my velocities, especially with surplus 8208. I heard the lot I have is a little slow. I already have a good, safe load developed. Very conservative. I'd just like to know the velocity of the load. It could be 2500 or 3000 fps. I just don't know. |
|
One or a couple of the guys on 68forums bought them. So far they are very happy.
They are consistently reading velocities that would be correct for the muzzle according to their other standard chronographs, and factory data. My concern with it, is gases and powder residue over time deteriorating the accuracy, or the electronics. If, after much use, it fails completely, that would be ok I suppose, but my fear is that it would degrade slightly over time, and could lead to erroneous loading practices. |
|
Quoted: While I aplaude new technology, my only concern is how it attaches to the barrel..... or better put, won't attach to a 1911 or Beretta ( as far as I could tell ).... I need my use specific tools to work on all my firearms. +1 I might be interested if they come up with a shoot though version |
|
Quoted:
What about the vibrations this will cause on the barrel while firing? Anything that attaches to the barrel will cause problems IMO. The point is to measure bullet speed. The simple installation forces a compromise and means that accuracy shooting can't be done simultaneously; that means an extra cost in components, time, and barrel life is superimposed on the cost of the instrument. |
|
Quoted:
Quoted:
What about the vibrations this will cause on the barrel while firing? Anything that attaches to the barrel will cause problems IMO. The point is to measure bullet speed. The simple installation forces a compromise and means that accuracy shooting can't be done simultaneously; that means an extra cost in components, time, and barrel life is superimposed on the cost of the instrument. My guess is the prox. probe detectors would be a little more accurate and dependable. No worries with ambient light, or muzzle flash interference. Those kinds of probes have to get closer to the bullet to be effective. I think that is why that type are held tight to the bbl of the firearm under test. It is not absolutely necessary to tie the probe support frame to the barrel, but it is probably most convenient to make the alignment. In my little world, mixing accuracy shooting and chronographing is never done. IMO you come nearer shooting your chronograph trying to mix the two. That gets particularly worrisome chronying pistols. My "garage chronograph range" is only 20 feet long. Anyway, we have made great strides in the chronograph arena over the years. Back in the 60's they used "shoot through" gold over copper plated conductive grids on mylar backing. We counted pulses made by crystal driven oscillators and gated TTL circuits and converted number of pulses to velocity by calculator or look up tables. |
|
Quoted:
Quoted:
Quoted:
What about the vibrations this will cause on the barrel while firing? Anything that attaches to the barrel will cause problems IMO. The point is to measure bullet speed. The simple installation forces a compromise and means that accuracy shooting can't be done simultaneously; that means an extra cost in components, time, and barrel life is superimposed on the cost of the instrument. My guess is the prox. probe detectors would be a little more accurate and dependable. No worries with ambient light, or muzzle flash interference. Those kinds of probes have to get closer to the bullet to be effective. I think that is why that type are held tight to the bbl of the firearm under test. It is not absolutely necessary to tie the probe support frame to the barrel, but it is probably most convenient to make the alignment. In my little world, mixing accuracy shooting and chronographing is never done. IMO you come nearer shooting your chronograph trying to mix the two. That gets particularly worrisome chronying pistols. My "garage chronograph range" is only 20 feet long. Anyway, we have made great strides in the chronograph arena over the years. Back in the 60's they used "shoot through" gold over copper plated conductive grids on mylar backing. We counted pulses made by crystal driven oscillators and gated TTL circuits and converted number of pulses to velocity by calculator or look up tables. I have to agree here. I don't chase accuracy and velocity at the same time. I have a hard time getting concentration on my shooting technique and mot shooting the chrony. Besides, I do the chrony testing in the back yard, where I basically have about 50 yards now. My concern is that I get a good reading on the projectile each time. I work up my loads for velocity first, up until I hit pressure signs, ( 6.8 ), or in the case of other calibers with more well established data, until I either meet the data max for powder charge or the velocity max, as long as neither show signs of pressure. At that point, I will take a range of loads that are safe in larger batches out where I can do longer range accuracy tests. I will pick from the most accurate, and then manipulate the load length, and retest to find my most accurate load, and then, I will shoot over the chrony again to get the exact data. Or, I will do a ladder test and develop loads that way for well established calibers, and after finding my top load, shoot over the chrony for the data. What this thing will do for me, is to make it much easier to check for velocity data, since I won't have to set the chrony up outside, along with everything else. And, in bad weather, I can just open the back door and shoot from inside the house and still get data, without the need to set up and lighting for it. Just a much quicker and easier option. |
|
I shoot over the chronograph both ways, but my tendency is to develop the load first, mostly to save time.
So I guess I never know exactly which path I'll take when I go to the range with the chronograph. In any case, this new instrument is expensive compared to its competition, although I suppose a full up Chrony is probably approaching that price these days, I haven't priced one in ten years or more; the one I own is still free of bullet damage. |
|
Quoted:
I might as well tell you my opinion about your plan - you'll never, ever, measure pressure with a chronograph. A chronograph measures bullet speed. THIS. The only pressure data you can infer from a chronograph is the average pressure used to drive the bullet, since THAT is what determines speed. The problem is peak pressure is what blows things up, and the only ay to get a reliable idea of tat is with a strain gauge system (or a full up piezo system). |
|
Quoted:
I've never use a chronoghraph. They look a bit complex and overwhelming. You shoot a bullet over them and it tells you how fast it went. Nothing complex at all. I've been doing a fair amount of internet research on chronographs and have come to the conclusion that all of them are about the same, except that the more you spend gets a bit more accuracy. The big difference is having a separate display on a cord instead of on the main body that goes down range. Totally worth the added cost. Then I saw the Magnetospeed chronograph at Magnetospeed.com. Different to say the least. It straps onto the barrel and uses electomagnetic field interference to measure speed. Nothing optical. Looks like a bayonet. I am seriously considering purchasing one, especially for developing loads with surplus powders. Does anybody have any experience with this new fangled contraption? Have not used them, but you can't use them on a pistol so IMO they're mostly useless. |
Armory Sponsor