Chronograph

[3oh8er]

I've been thinking of buying a chronograph and have a question.
Has anyone shot their chrono for muzzle velocity and then moved it 100 yds downrange to record the velocity so that a verification or adjustment can be made to range tables or ballistics data?
If there is an existing thread please direct me there.

 

[B3dlam]

Re: Chronograph

I think what you are talking about is measuring the BC of a bullet you can by taking velocity measurments at known distances then adding in the atmospherics and everything come out with the True BC for that bullet. I have never tried as measuing at one point usually 10-20' infront of the muzzle has worked just fine for me.

 

[redbullitt]

Re: Chronograph

Same here, a bit out in front has always worked as well. The only reason I would put it out a bit further (just a little mind you) would be if muzzle blast was messing with my readings.

I think I get what you are saying though. I just have never really had a need to do that. I usually just take it out to distance and shoot a bit. If the drop lines up well, I'd say everything is in order.

Lots of chronographs get killed at 15 feet, i bet more would die at 100 yards lol.

 

[gstaylorg]

Re: Chronograph

With the type of chronograph that you shoot between the sensors and overhead screens, you'll have to be extremely careful if you try to use it at a distance. It's pretty easy to put a round through one accidentally, even when it's close up. Just sayin.

 

[Aries64]

Re: Chronograph

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 3oh8er</div><div class="ubbcode-body">I've been thinking of buying a chronograph and have a question.
Has anyone shot their chrono for muzzle velocity and then moved it 100 yds downrange to record the velocity so that a verification or adjustment can be made to range tables or ballistics data?
If there is an existing thread please direct me there. </div></div>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gstaylorg</div><div class="ubbcode-body">With the type of chronograph that you shoot between the sensors and overhead screens, you'll have to be extremely careful if you try to use it at a distance. It's pretty easy to put a round through one accidentally, even when it's close up. Just sayin. </div></div>
<span style="font-weight: bold"><span style="font-style: italic">3oh8er</span></span> -

<span style="font-weight: bold"><span style="font-style: italic">gstaylorg</span></span> is correct. Any chronograph that the projectile has to pass through/pass between (such as chronographs that use "<span style="font-style: italic">Skyscreens"</span> or Infrared sensors) is susceptable to damage, even at close range. Some simple, common sense rules for personal and equipment safety are (a) always keep your finger off the trigger until ready to fire, (b) never velocity test an un-zeroed gun, (c) always be extremely careful to be sure that the barrel is perfectly centered and square with the frame of the chrono's skyscreens or sensor box, and that you take the scope height into account so that the bullet will pass directly through the "sweet spot of the chronograph, and (d) <span style="font-style: italic">never let anyone use your chrono.</span>

The above said, I never setup my chronograph any further than 15 feet in front of my bench. Why? Because even though I'm confident that <span style="font-weight: bold"><span style="font-style: italic">I</span></span> won't shoot my PVM's "sensor box", the tripod or Head, I have no control over the shooting of anyone else at the range. There's always several jackasses who setup their target frames well off-axis instead of 12:00 of their shooting position. That's annoying enough 100 yards, but when they're shooting off-axis at 50 yards oftentimes they'll shoot people's 100 yard frames. And that doesn't even take ricochets into account. If you have your own private range then you're <span style="font-style: italic">probably</span> OK, but you'll still want to be really careful.


Keith

 

[jdr724]

Re: Chronograph

most ranges have set distances they allow chrono's at since shooting anything except paper isn't allowed.

Use the velocity at the muzzle, scope height, bullet weight etc..... with a ballistic calculator to determine your dope then check that at distances to verify. if you find it's not spot on, go back and check your input data.

 

[3oh8er]

Re: Chronograph

Thanks for all the info and advise.