Chrono use questions

[Paul5388]

Asking would have taken all the fun out of the quest.

I have to admit, it taxed my 9th grade Spanish quite a bit, especially since 9th grade was in 1959 and I don't think I've been to Spain since 1964.

 

[AzShooter]

I always use 4 paces which comes out to be about 12 ft. I aim 4 to 6 inches over the chrono and have a cardboard target attached to it so I don't drop a shot into the chrono itself.

I lend it out because the maker says if a bullet goes threw the unit it's only a $30 repair.

I've hit it a few times when not using the targets so now I make sure they are on there. A few nicks and scratches have added a je'ne se qua to the unit... Probably spelled that wrong.

Last month a guy at the table next to me asked if he could shoot over it and I said sure, just give me $30 if you hit it. He fired a few shots and got the data he needed.

In all honesty it takes more shots for a valid reading then people normally take. 10 shoots do not show enough variables but is good for most cases.

 

[Wheelgunner840]

I also set the chrono out to about 12-15 feet. I find that lining it up with a target in such a way that the bullets fly over it in exactly the same direction and angle from front to back helps make for more consistant monitoring. Shooting from a benchrest will also allow for more precise readings as it helps to maintain the same bullet path.

rewster

WG840

 

[R Cubed]

Here the thing that happens when you start to chronograph your loads;

You wonder if you can make them more consistent...
Research starting into that subject...
Ya buy a book or two, or more...

Then start on the hardware...

Ya buy a quality case trimmer and a caliber...
Ya start trimming each case to exactness...
Somewhere in this maddness you begin trickling each charge instead of only spot cheching every so often on the scale...

The maddnes is in full fuster when you buy an RCBS Case Master (that's what I use) or something simular and start in on case neck and bullet run-out... Ya want 'um to fly straight right?

Your already cleaning the primer pockets and reaming the flash hole, deburring the case after trimming to within 0.0005" or a tighter tolerance!!!

So ya find yourself a caseneck micrometer to start gaugeing wall thichness and a standard micrometer for measureing case neck diameter...

Then insanity is full set in when you start looking for something like the RCBS mic dies to start in on head space... Have not found one for .30-30 yet, I don't think RCBS made one for .30-30 and the auction boards want too much for the .30-06 and .223 ones . . . sniffle sniffle

 

[Wayne02]

I am shopping for a Chrono at this time but wanted to ask for any tips in terms of set-up in my particular situation.

Outdoor range, but both the firing line and the target stands are covered. Most of the distance between the two is open.

Fixed target distance of 25 yards. You must walk out to the target stand to change paper.

Bullseye paper target only, all rounds must be on the paper.

Technically we are not supposed to sit or kneel at the bench. Standing only but you can use one of the different height wood boxes as a rest if desired.

Limited amount of time to set-up chrono during ceasefires (not supposed to hold up other shooters)

The chrono/screens will be mounted on a camera tripod.

I have a pistol rest I can use which has adjustable elevation.

How about this idea for initial set up. I put the pistol rest on top of one of the wood boxes which is set on top of the bench. Then put a bore sighter in the barrel of an empty gun (or just the barrel out of a semi) and set the gun/barrel in the pistol rest pointing at the target with the laser lined up on the bullseye.

Then I set the chrono/tripod up such that the laser passes through the screens and to the target.

 

[R Cubed]

Originally posted by Wayne02:
I am shopping for a Chrono at this time but wanted to ask for any tips in terms of set-up in my particular situation.

Outdoor range, but both the firing line and the target stands are covered. Most of the distance between the two is open.

Fixed target distance of 25 yards. You must walk out to the target stand to change paper.

Bullseye paper target only, all rounds must be on the paper.

Technically we are not supposed to sit or kneel at the bench. Standing only but you can use one of the different height wood boxes as a rest if desired.

Limited amount of time to set-up chrono during ceasefires (not supposed to hold up other shooters)

The chrono/screens will be mounted on a camera tripod.

I have a pistol rest I can use which has adjustable elevation.

How about this idea for initial set up. I put the pistol rest on top of one of the wood boxes which is set on top of the bench. Then put a bore sighter in the barrel of an empty gun (or just the barrel out of a semi) and set the gun/barrel in the pistol rest pointing at the target with the laser lined up on the bullseye.

Then I set the chrono/tripod up such that the laser passes through the screens and to the target.

I go out on BLM land about 25 miles from the house and shoot againt a mountain. No fees, no pre-set anythings. I set up and shoot how I want to with safety in mind. I have been to enough ranges to know what is necessary and how to remain safe. If you feel constrained at the range, see if BLM land is an option for you.

BLM land is public use land, you can shoot on it! Be safe.

 

[Cary]

A couple of tips on using the chronographs. If you are using one without the sky screens and want the rods on it for sighting purposes you can replace the metal rods with some of those colored plastic straws. If you hit one of the straws it will not damage your chronograph. Some people also use wooden dowels to support the sky screens. They claim the wooden dowels will break away if hit without damage to the chronograph as well. I have personally used the straws but not the wooden dowels.
Cary

 

[AzShooter]

You've got the right idea. Setting up the chrono so that your rounds will be going throught the center can be a paain but with your system it should only take a couple of seconds and no one will be warry of the time.

At our range we have shooters walking out to 200 yards which gives pleanty of time. As long as you are faster than the slowest guy on line you are doing great.

 

[H Richard]

I use about 12 ft. because that is the length of the cord for the connection to the read-out head on my Beta Chrony. I got the Beta model after I just "slightly" touched my F1 Chrony with a .44 mag going nearly 1400fps. Chrony will give you a real good trade in value regardless of condition toward a new model.

 

[Peter M. Eick]

R-cubed.

I recognize Dr Mann's a bullets flight and Rinker's understanding ballistics but what are the other two?

 

[1x2]

What would be wrong with this? When the line's clear go down and set up a target. When the shooting starts, start shooting. Shoot about 16 rounds. Who's counting? Next time the line's safe, set out your chrono, then wander down to the backstop and look at your target (oh, nice shooting!). Go back and shoot through the chrono; if you don't hit the target, who will know?

BTW, I do all my load testing through my chrono while sitting on the ground with my forearms resting on my knees- it works fine, and I've never hit the chrono.

If someone complains that you're not shooting at paper, go down and set up a square of 4 targets ~ 3ft off the ground; you're bound to hit one of them...

1x2

 

[R Cubed]

Originally posted by Peter M. Eick:
R-cubed.

I recognize Dr Mann's a bullets flight and Rinker's understanding ballistics but what are the other two?

The Mann book is a 1952 printing Copyrighted 1909 - When I got it it loooked as if it had never been read. What a shame. The other two are what started the rapid downward slide into reloading and ballistics.

One is Wayne Zwoll's "The Hunters Guide to Ballistics" and the other is Zwoll's "The Hunter's Guide To Accurate Shooting". I can be obsessive when something captures my attention...

Thanks for asking... It is maddness you know!!!

 

[Wayne02]

Originally posted by 1x2:
What would be wrong with this? When the line's clear go down and set up a target. When the shooting starts, start shooting. Shoot about 16 rounds. Who's counting? Next time the line's safe, set out your chrono, then wander down to the backstop and look at your target (oh, nice shooting!). Go back and shoot through the chrono; if you don't hit the target, who will know?

That's a real good idea. I think once I get the setup nailed down for some repeatability there really shouldn't be any problem shooting through the crono and being on the paper.

 

[shovelwrench]

No one mentioned the Caldwell Hammer (cheaper sister to the Ransom, acctually I hopped in here through a link in another thread and have no idea what this one is about, seemed releavant though)

Originally posted by thomashoward:

Originally posted by pinkymingeo:
Second the bench rest. I shot several diffusers and support rods before I finally came to my senses and began shooting over a rest.

That's why I use this contraption. I don't worry so much about shooting the Chrony

ANYWAY,
How well does this setup work, I have the same chrony. No rods to deal with, I LIKE IT..

 

[R Cubed]

Originally posted by shovelwrench:
No one mentioned the Caldwell Hammer (cheaper sister to the Ransom, acctually I hopped in here through a link in another thread and have no idea what this one is about, seemed releavant though)

Originally posted by thomashoward:

Originally posted by pinkymingeo:
Second the bench rest. I shot several diffusers and support rods before I finally came to my senses and began shooting over a rest.

That's why I use this contraption. I don't worry so much about shooting the Chrony

ANYWAY,
How well does this setup work, I have the same chrony. No rods to deal with, I LIKE IT..

I wonder how stable it in a breeze. I hang a gallon jug of water just above the ground from my tri-pod mount. (I use the rods). This forces the legs apart and does increase stability.

The bucket is interesting innovative adaption of materials at hand to solve a problem. Good job! Yoou karma should go up a point or two with that.

 

[7P's]

One post touched on the subject of shock wave - it's a valid concern. If your loads are supersonic then all is well but if you are shooting subsonic your readings will probably be inconsistent at best due to the shock wave. Place a baffle half way between the end of your barrel and the 1st skyscreen. You can use a 4'X2' piece of plywood with a 2" slot cut in the middle running from the top down 18". You can use a smaller slot if you desire but I wouldn't recommend going any larger. By using a baffle you will prevent inconsistent readings with subsonic loads.