Range Report How far should the chronograph be from the gun?
- Thread starter shootist2004
- Start date
Re: How far should the chronograph be from the gun?
From CED web site : http://www.cedhk.com/show.php/Object29 §Variables that will effect results (bottom)
<span style="font-style: italic">4. Muzzle blast - If the muzzle blast reaches the first sensor before the projectile, your results may be in error or not recorded at all. If the muzzle blast causes your screens to shake, the readings could also be affected. Suggestion - when using high powered rifles move back away from the chronograph sensors (12 - 18 feet), until proper velocities are recorded, and then move forward one foot at a time, to determine the closest distance at which each weapon will perform at. Then record that information for future use. Different calibers, brands, barrels, and ammunition will affect the distance, so it may be necessary to test each accordingly.</span>
Most users set the start within 9-10 feet (3m).
From CED web site : http://www.cedhk.com/show.php/Object29 §Variables that will effect results (bottom)
<span style="font-style: italic">4. Muzzle blast - If the muzzle blast reaches the first sensor before the projectile, your results may be in error or not recorded at all. If the muzzle blast causes your screens to shake, the readings could also be affected. Suggestion - when using high powered rifles move back away from the chronograph sensors (12 - 18 feet), until proper velocities are recorded, and then move forward one foot at a time, to determine the closest distance at which each weapon will perform at. Then record that information for future use. Different calibers, brands, barrels, and ammunition will affect the distance, so it may be necessary to test each accordingly.</span>
Most users set the start within 9-10 feet (3m).
Re: How far should the chronograph be from the gun?
I usually set mine about 10' and don't have any problems with blast.
I usually set mine about 10' and don't have any problems with blast.
Re: How far should the chronograph be from the gun?
Whatever distance you pick, make sure it's the exact same every time. To help me with that, I have marks on my Chrony Master's cable that show 12 feet, which I use to measure from the front of the first screen/sensor to the muzzle of the rifle.
Whatever distance you pick, make sure it's the exact same every time. To help me with that, I have marks on my Chrony Master's cable that show 12 feet, which I use to measure from the front of the first screen/sensor to the muzzle of the rifle.
Re: How far should the chronograph be from the gun?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JpS</div><div class="ubbcode-body">From CED web site : http://www.cedhk.com/show.php/Object29 §Variables that will effect results (bottom)
<span style="font-style: italic">4. Muzzle blast - If the muzzle blast reaches the first sensor before the projectile, your results may be in error or not recorded at all. If the muzzle blast causes your screens to shake, the readings could also be affected. Suggestion - when using high powered rifles move back away from the chronograph sensors (12 - 18 feet), until proper velocities are recorded, and then move forward one foot at a time, to determine the closest distance at which each weapon will perform at. Then record that information for future use. Different calibers, brands, barrels, and ammunition will affect the distance, so it may be necessary to test each accordingly.</span>
Most users set the start within 9-10 feet (3m). </div></div>second this I was getting inaccurate readings due to being to close and did not know what the issue was till I posted here on the hide.
I was shooting a 338 lapua and a 375 cheytac. from now on I will always be 12 feet away
suggest you just keep it the same for all calibers so you have a repeatable reading / distance
Bill
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JpS</div><div class="ubbcode-body">From CED web site : http://www.cedhk.com/show.php/Object29 §Variables that will effect results (bottom)
<span style="font-style: italic">4. Muzzle blast - If the muzzle blast reaches the first sensor before the projectile, your results may be in error or not recorded at all. If the muzzle blast causes your screens to shake, the readings could also be affected. Suggestion - when using high powered rifles move back away from the chronograph sensors (12 - 18 feet), until proper velocities are recorded, and then move forward one foot at a time, to determine the closest distance at which each weapon will perform at. Then record that information for future use. Different calibers, brands, barrels, and ammunition will affect the distance, so it may be necessary to test each accordingly.</span>
Most users set the start within 9-10 feet (3m). </div></div>second this I was getting inaccurate readings due to being to close and did not know what the issue was till I posted here on the hide.
I was shooting a 338 lapua and a 375 cheytac. from now on I will always be 12 feet away
suggest you just keep it the same for all calibers so you have a repeatable reading / distance
Bill
Re: How far should the chronograph be from the gun?
I get 12-15 feet, more if shooting a larger caliber. With a supressor or muzzle brake, you can be a little closer, maybe 10-12 feet. But 15 feet is a good distance.
I get 12-15 feet, more if shooting a larger caliber. With a supressor or muzzle brake, you can be a little closer, maybe 10-12 feet. But 15 feet is a good distance.
Re: How far should the chronograph be from the gun?
I put it about 5 steps away from the firing line.
I don't believe in banking on chrono numbers any closer than by about 50fps. Expecting more precision is simply impractical.
That's because they all have a built-in error margin of about +/-1% on each velocity reading. Read the manual, it's all right there in black and white.
With a reported velocity of 2500fps that's actually 2500fps +/- 25fps; or somewhere, nobody knows precisely, between 2475fps and 2525fps.
Basing decisions and calculations on numbers with any finer accuracy than that 50FPS fudge factor span is simply a matter of venturing into the realm of fiction. At 3000fps, it's maybe 60fps, and at 3500fps, it's more like 70fps.
That's why I get a real charge when folks start bantering about ES/SD values in the single digits, and scratching their heads when their calcs don't deliver a vertical accuracy of an inch or three at 1000yd.
The real world simply doesn't work that way.
Double digit ES/SD values can only be considered as ballpark estimates, accurate to +/- 25-30fps at best. Single digit values are pure fantasy.
Greg
I put it about 5 steps away from the firing line.
I don't believe in banking on chrono numbers any closer than by about 50fps. Expecting more precision is simply impractical.
That's because they all have a built-in error margin of about +/-1% on each velocity reading. Read the manual, it's all right there in black and white.
With a reported velocity of 2500fps that's actually 2500fps +/- 25fps; or somewhere, nobody knows precisely, between 2475fps and 2525fps.
Basing decisions and calculations on numbers with any finer accuracy than that 50FPS fudge factor span is simply a matter of venturing into the realm of fiction. At 3000fps, it's maybe 60fps, and at 3500fps, it's more like 70fps.
That's why I get a real charge when folks start bantering about ES/SD values in the single digits, and scratching their heads when their calcs don't deliver a vertical accuracy of an inch or three at 1000yd.
The real world simply doesn't work that way.
Double digit ES/SD values can only be considered as ballpark estimates, accurate to +/- 25-30fps at best. Single digit values are pure fantasy.
Greg
Re: How far should the chronograph be from the gun?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">That's because they all have a built-in error margin of about +/-1% on each velocity reading. Read the manual, it's all right there in black and white.
With a reported velocity of 2500fps that's actually 2500fps +/- 25fps; or somewhere, nobody knows precisely, between 2475fps and 2525fps.</div></div>
I have similar conversations with people, cars and dyno runs. They think that their car produces 507.32 HP--yet the last 3 digits are in question due to the precision of the dyno, not to mention the fuel, atmospheric pressure, and humidity.....
Only REAL expensive chronometers (the ones noone of us can afford) are capable of measuring shot-to-shot, day-to-day, month-to-month accuracies of a foot per second.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">That's because they all have a built-in error margin of about +/-1% on each velocity reading. Read the manual, it's all right there in black and white.
With a reported velocity of 2500fps that's actually 2500fps +/- 25fps; or somewhere, nobody knows precisely, between 2475fps and 2525fps.</div></div>
I have similar conversations with people, cars and dyno runs. They think that their car produces 507.32 HP--yet the last 3 digits are in question due to the precision of the dyno, not to mention the fuel, atmospheric pressure, and humidity.....
Only REAL expensive chronometers (the ones noone of us can afford) are capable of measuring shot-to-shot, day-to-day, month-to-month accuracies of a foot per second.
Re: How far should the chronograph be from the gun?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Whatever distance you pick, make sure it's the exact same every time. To help me with that, I have marks on my Chrony Master's cable that show 12 feet, which I use to measure from the front of the first screen/sensor to the muzzle of the rifle. </div></div>
Now there's a good tip!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">Whatever distance you pick, make sure it's the exact same every time. To help me with that, I have marks on my Chrony Master's cable that show 12 feet, which I use to measure from the front of the first screen/sensor to the muzzle of the rifle. </div></div>
Now there's a good tip!
Similar threads
