HOW FAR from Chronograph??

[shooterrdy]

when using graph how close do you have the muzzle to the graph? I was about 5-6 Feet with a 300 WM with Little Jimmy brake.

I was getting speeds that were 140-160 Fps slower than book said I should be. 4831 SC 72.3 grain 210 grn VLD COAL 3.50 federal mag primer graph shows 2664 3 shot avg. book says should be 100 fps faster
and my barrel is an inch longer (25") 1/10 twist.

any input on graph distance would be great Thanks

 

[CoryT]

Standard is 10ft, but I sometimes go even further to prevent muzzle blast from affecting the readings.

 

[Dshooter]

Mine goes right on the end of the barrel

 

[dave300]

When I had an Oehler, 20' was the distance I was taught and did not have any issues following the advice I was given. I have switched to the Magnetospeed V2 and the distance became a moot point as you may or may not know, the bayonet attaches to the barrel.

 

[JGorski]

when using graph how close do you have the muzzle to the graph? I was about 5-6 Feet with a 300 WM with Little Jimmy brake.

I was getting speeds that were 140-160 Fps slower than book said I should be. 4831 SC 72.3 grain 210 grn VLD COAL 3.50 federal mag primer graph shows 2664 3 shot avg. book says should be 100 fps faster
and my barrel is an inch longer (25") 1/10 twist.

any input on graph distance would be great Thanks

I'm about the same as you, haven't had any issues thus far.

 

[SWThomas]

I go about 12 feet.

 

[High Binder]

It really doesn't matter so long as you place it the same distance every time.

 

[damoncali]

6 inches. Or 10-15 feet if you're not blessed with a Magnetospeed. Sometimes the book is wrong. Just the nature of uncertainty.

 

[AIdog]

what do u guys think about the shooting crony f1? i know its not top of the line but is it reliable?

 

[leadbullet]

Chrony F1 are garbage, I have three of them and the all show different speeds in the order of several 100 FPSvariance from one to the other. I dont chrono anymore, waste of time, barrel life and money. Shoot at distances and calculate your speed from there if you really need to know.
cheers.

 

[Nortex]

What book are you referencing? I think some can be deceiving like Nosler as they are using match grade barrels and chamber's which can increase velocity/pressure compared to a factory job.

 

[wxl]

Very possible it is the book. Look in 3 different load books and probably see 3 different load recipes, different min and max charges. Which one is right?

 

[bruddah]

Mine goes right on the end of the barrel

When I had an Oehler, 20' was the distance I was taught and did not have any issues following the advice I was given. I have switched to the Magnetospeed V2 and the distance became a moot point as you may or may not know, the bayonet attaches to the barrel.

Ditto.

 

[shooterrdy]

Thanks Men, I tried mine against a friends and I was 70 FPS slower , shot one then the other, I read up and find that I need to move to a consistent lighting area and the even the time of day can make a difference. 100 FPS does not make that much of a difference on a ballistic computer for overall hold overs etc. I think I am good I will give RCBS a call and see if it can be sent in for calibration. Thanks for the replies.

 

[bruddah]

Thanks Men, I tried mine against a friends and I was 70 FPS slower , shot one then the other, I read up and find that I need to move to a consistent lighting area and the even the time of day can make a difference. 100 FPS does not make that much of a difference on a ballistic computer for overall hold overs etc. I think I am good I will give RCBS a call and see if it can be sent in for calibration. Thanks for the replies.

Depends on how far away the target is and it's size. 1,000 yds away and you'll miss by a mile.

 

[shooterrdy]

Agreed The better the Data the closer the computer will be no doubt this makes my problem graph seem that even if it were not reading slow it still could be wrong. What type of Graph would you recommend and what kind lighting do you use?

 

[Victor N TN]

what do u guys think about the shooting crony f1? i know its not top of the line but is it reliable?

Shooting Chrony was the first chronograph I had. It gave a lot of funny readings. I got another. It was the same way. Long story short, I've had 3. I gave one to my brother. And got rid of the other 2 as well. You COULD NOT give me anything with Chrony in the name. My Pact has done me very well. The next one I get will probably be a CED M2.