Chronograph distance question

8shot

8shot

Member
Joined
Feb 14, 2005
Messages
361
Reaction score
328
Location
Upstate NY
I have a vintage "Chrony" that has served me well for many years and which I need to brake out again.

What is the suggested distance one should be from the Chrony to get the most accurate FPS reading? Have you seen any significant discrapencies using varying distances?

Thanks
 
Register to hide this ad
I began chronoing about 30 yrs. ago with a Chrony and they seen to be less touchy than more expensive models. You need to be far enough back so the muzzle blast doesn't mess up results. If you're chronoing scoped rifles be sure and hold high enough to compensate for the height of the chrono. I shot my first Chrony with 223 ammo from my Mini 14. The bullet just skimmed the top edge of the Chrony which was more than enough to kill it! The Chrony company is/was very understanding.
 
Unless I want my .357 loads clocking 3,000 fps one shot and 18 fps the next mine needs at least 10 feet distance to escape muzzle blast. It can be a bit closer with something like .32 ACP, a bit farther with something more intense.
 
Don't know how long I owned this Chrony..has to be 25 years plus? Following the site marks on the shades never had a problem hitting it. Using a Lee Loadmaster to drop powder and the charges seem consistent by checking the drops with my RCBS balance scale... but get FPS differences in the 30 fps range. Probably standing somewhere in the 10 foot range "so I can see the alignment marks :-)"

BTW: shooting lead 38spl bullets out of a revolver in the 800-900 fps range.
 
Last edited:
I'm still using my old, red, F1 Shooting Chrony. 10 feet from the muzzle with non-magnum handgun loads. With magnum handgun loads, especially with H110/W296, you might want to go 15 feet to get away from the muzzle to avoid chronographing the fire ball and ejecta.

If I had to buy a new chronograph, I might follow in HorizontalMike's footsteps and invest in a LabRadar.
 
I used roughly ten feet with the screen chronographs. I didn't measure the distance; it's not critical for getting an accurate reading.
 
stansdds said:
I'm still using my old, red, F1 Shooting Chrony. 10 feet from the muzzle with non-magnum handgun loads. With magnum handgun loads, especially with H110/W296, you might want to go 15 feet to get away from the muzzle to avoid chronographing the fire ball and ejecta.

If I had to buy a new chronograph, I might follow in HorizontalMike's footsteps and invest in a LabRadar.
Click to expand...

This is my experience exactly. And if starting over again, I would do the LabRadar unit too. I ran across a guy using one at the range one day and fell in love with it, except for the hit my pocket would take to buy it.
 
muddocktor said:
This is my experience exactly. And if starting over again, I would do the LabRadar unit too. I ran across a guy using one at the range one day and fell in love with it, except for the hit my pocket would take to buy it.
Click to expand...

Well... after shooting up a couple of other chrono's,... LabRadar sounds cheaper and cheaper, in the long run.
 
I think the LabRadar and the Oehler 35P are about the same price, around $600.00. The Oehler does require a bit longer setup time, but it gives up nothing to the LabRadar. Both are very good units.
 
I set my distance per weapon being tested.

My off hand 12 Ga. shotgun loads get 3-4 feet from the unit for my readings.

My pistols all work at 10 to 12 feet depending on regular or +P loads.

I learned to use at least 12 feet, more is better with heavy rifle loads and heavy muzzle blast.

I still have my factory metal rods but I did wrap them with some orange tape to aid in my centering shots, to help miss the unit.

Have fun.
 
I have never shot a chronograph, and you won't either if you do one simple thing before firing a shot. Set up your chrono 10 feet or so in front of the bench. I use a Caldwell pistol rest and measure about an inch or above where you rest the pistol barrel, to the ground. I have my Oehler mod 33 "eyes" on a 10' piece of conduit, with a tripod mount bolted on the tubing. If say, my pistol rest measurement was 50" to the ground, I put my conduit measuement at 40", giving me 10" above the "eyes". Setting it up like this, I've never shot any parts on my chrono. And, never let some bozo shoot over it. Those are the guys that will shoot it for you.
 
I have never owned a Chrony

I set my sky screens 10 feet from the muzzle

I started with Ohler 33 and 43 back 30+ years ago. A "buddy" put a bullet through my Ohler 33 sky screens. Doc Ohler was most generous and provided replacement sky screens plus upgraded my unit at no charge

I have had two of the CED units. I liked that they called out the velocity of each shot. They also had qan infrered lighting system for use on indoor ranges that worked very well.

I have a Mag-Net-O-Speed, but it only works for some rifles . . . . or handguns with suppressors

And I have a LabRadar

Since we do most of the chronographing on my buddies farm, I always bring two chronographs with me. I hate to make the almost 2 hour drive (each way) for nothing

I love the LabRadar datafile that gives projectile velocity for every shot measured ever few micro seconds.

It is also pretty cool to set up in 10 seconds

Plus now you can use the smart phone app to interface with the LabRadar

I will say that the LabRadar casing is not as durable as it could be. Several portions of mine have broken off or cracked. Now that has never altered functionality, but the unit shows poorly
 
I set my screens up at 12 feet or so with my Chrony.
That's usually enough for everything but the big blasty rifles.

I set up so the bullet goes as high as possible, just below the plastic sunshade.
If anything, I'd rather hit the plastic sunshade at the top than my chrono.
 
From what I've seen it is less common to shoot the actual chronograph unit and more common to shoot one of the sunshade support rods. Since most of them are steel, and the body of the chronograph is often plastic, hitting the rod with something moving as fast as a bullet does catastrophic damage to the case.

So I replaced mine with 3/32" fiberglass rods. They are plenty strong enough for what they do, but if I hit one with a bullet it will just shatter without destroying the case of my chronograph.
 
If you use a chronograph a lot for decades, you'll eventually hit a chronograph component or the chronograph itself (if there are any of those machines still in use where the main unit is in front of the shooter). Those who haven't done so probably haven't been using a chronograph long, chronograph fewer than a couple of thousand rounds annually, or are incredibly lucky.
 
Long ago I had the borrowship of a Oehler 33 chronograph. It had a set up for 2 sky screens separated on a conduit pipe 4 feet apart. Then a wire some twenty feet or more to the computer on the table. It worked rather well if the light direction was proper. Cloudy days read different from clear and contrast bright. About that time I got my first Chrony folder. They displayed very close in values. I got from Chrony a push button switch and a 16ft wire so I could stay behind line of fire to change shot strings. Later on I tried clocking twenty gauge rifled slugs from a "safe" distance and hit the readout screen on the Chrony with the plastic wad mashing it. I guess the 16' wire from the manfu meant 16 feet from muzzle. I learned to manipulate the screen diffusers so the sky screen would not be in direct sun light, or overcast days would do the same thing.
 
For pistol, 6-10' works fine for me. Just be sure to use a rest and have an aiming point beyond the chrony to make your shot pass more or less vertically centered between the screens and the unit.
Center fire rifle, I be sure the chrony is 10' away, and always off a rest at an aiming point.
 
You must log in or register to reply here.

Similar threads

4
44 mag ammo question
Replies
13
Views
555
Yendor357
Y
S
A question about military ammi
Replies
8
Views
464
crows
C
O
32 auto question
2
Replies
39
Views
2K
BrBa
B
P
44 Russian ammo question...
2
Replies
26
Views
2K
unspellable
U
Rustywrench
Question on 9 mm Ammo for 39-2
Replies
17
Views
852
Rick H.
R

Latest posts

Back
Top