OK, about every 4 shots through my beta master, on the next shot, the plastic screens pop off of the rods,severely pissing me off. This is at a distance of about 8 ft. Anyone have any tips/suggestions?

Try moving the chronograph out farther. The first screen should be about 12 ft away from the muzzle. I prefer 15 feet. Not only is the muzzle blast blowing off the plastic screens but you are probably also getting false readings.

Larry Gibson

Yeah, 12 to 15 feet for the first screen. I could never quite figure out why screens got "shot."

I'd been setting them up too close to the muzzle, and reading the particulate from the muzzle blast, not the bullet speed.

Yep, 8ft is waay to close. Move them back to at least 15, 20 is even better for magnum pistols & rifles.

Try moving it furter away. If you still have an issue (I did) I got a couple small bungee cords and drilled a small hole in the end of each sceen then attached the cord to the end and looped it under the bottom of the Chrony. Not the prettiest but funtional.

ha, thanks guys, i had been thinking i had created a miracle. 150gr 308 at 2950 out of a 20" barrel!!!!! Whats the best way to ensure that the bullet goes through the screens as opposed to into the rods?

Take the time during set up so that when you are in the bench position make sure the rifle, center of screens and target are properly lined up. I set the target up first, then the rifle on the rest/bags so when in shooting position it is aimed at the target and then set the screens up to coincide with the rifle target. I've seen more screens get shot by attempting to shoot multiple aiming points on the target while squirming around on the bench tring to line it up. Better to have not more than 2 aiming points (I space them about 3" apart vertically on a 100 yard target) and to get all positioned ensuring proper alignment of the rifle, screens and target before shooting. I also put a couple white pasters on the rods 4" up from the screens and never shoot if the cross hairs are lower than those pasters. Using the low end magnification of the scope when setting up and settling in to shoot also helps.

However, the biggest reason for shot screens (flinching isn't counted here ) is failure to zero at the test range before shooting over the screens.

Larry Gibson

quote:

... failure to zero at the test range before shooting over the screens.

Good point! An idea I had was to set up the chrono with the aid of one of those laser pointers or simply a barrel mounted laser sight (a bit hard to see during the day).

FWIW, I set my Beta Chrony at 10 feet. This effectively gives me a much larger window to shoot through than if it were out at 15 or 20 feet. As in 50 to 100% bigger. I have marked the signal cable with a Sharpie so it is perfectly set at 10 feet every time - no messing with tape measures any more.

To avoid blowing the screens off with muzzle blast, I tape them to the rods with blue painters tape. A strip of this placed across the rods, about 2 inches above the meter, also prevents me from ever shooting the meter by misjudging the scope-bore relationship.

I have even toyed with the idea of taping over the rods so they're more visible in the scope...

With this setup, I don't get false readings, even with 7mm Rem Mag, 338 Win Mag, etc. I find that false readings are a result of incorrect setup - make sure the diffuser screens are actually between the sun and sensors... They are not necessary on cloudy days, and sometimes you have to tilt the chrony on sunny days as the sun moves across the sky.

The advice about setting up the target, then rifle, then chrony is right on. When placing the chrony, it is easy to look through the "window" backwards, toward the rifle bore, and get it set dead center with no fuss.

Hope some of this helps. It works great for me.

One guaranteed way to break a Chrony is by hitting one of the screen legs.
This possibility can be removed by replacing the steel legs with wooden dowelling.
Mark the dowels halfway up with a sharpie for alignment with the horizontal crosshairs.

And if you are shooting a pistol through the chrono, do just like the rifle and fire it from a rested position. Don't do like I did years ago and hit the Chrony itself with a .45 JHP!

They did give me a discount on a new Beta Master though.

Put your rifle on the rest aimed at the target, use a laser bore sighter and a sheet of paper held vertically over each sensor to see where the bullet will pass and how your chrony is aligned. I'd opine that this is the foolproof method, but the fools keep fooling me.

quote:

Originally posted by Larry Gibson:
Try moving the chronograph out farther. The first screen should be about 12 ft away from the muzzle. I prefer 15 feet. Not only is the muzzle blast blowing off the plastic screens but you are probably also getting false readings.

Larry Gibson

I was chronographing my friend's 500 S&W and with (of course, the most expensive and hard-recoiling rounds) would get "error" readings. Finally solved the problem by moving the Chronograph further away from the muzzle blast. Never blew my screens off, though.

quote:

Originally posted by sputster:
And if you are shooting a pistol through the chrono, do just like the rifle and fire it from a rested position. Don't do like I did years ago and hit the Chrony itself with a .45 JHP!

They did give me a discount on a new Beta Master though.

There is one sure-fire way of making absolutely certain you will not blow your diffusers off or hit the rods. Don't use'em. If you chronograph on cloudy days, they are not necessary. Using plastic or wooden rods (as has been mentioned) is gentler on the chronograph than the metal ones when they do eventually get hit. (Why doesn't Chrony use them?)

After one misadventure, my chronograph now wears armor. (11 inches of channel iron between the sensors and another 11 inches in front of the instrument angled for deflection upward and staggered so lead shavings will not hit the sensor. Never again!)

Check out this thread for more stories of taking chronographs, including recipes, stuffing and mounting instructions.

https://forums.accuratereloading.com/eve/forums?a=tpc&f=2511043&m=446105658

It starts out with pictures of a Chrony that had been dismantled by a 405 grain 45-70 bullet travelling about 1700 fps.