Chrono distance

[adam]

I have set my chrono to 5 feet in front of the muzzle while working up some new loads but how much fps should I add to my results to get close to the actual muzzle velocity?

[broncsandwhiskey]

Hey adam I think that your setting your chrono to close to the muzzle. I set mine around 10 to 12 feet for my light guns and 15 feet for my big boomers. Your instruction manual should tell you how far to set the machine away so you do not damage it from muzzle blast. Also if your to close your muzzle blast could give you a false reading. So what ever Chrono you have I would move it out to at least 10 feet and also see what the manufacture has to say about it. Have fun and Ride Up!!!

[cracker]

this is strickly a quess but I dont think if you have your chrono within 15 ft of the muzzle that you need to add anything to your reading. I cant believe that a bullet would slow down much 10 to 15 feet out of the muzzle
Cracker

[Rick in Oregon]

There is a correction formula to muzzle velocity based on how far the chrono is from the muzzle, but I just plain forget what it is....if you add about 15 - 20 fps, you should be purty close. That amount of velocity won't affect anything, so be content with what the chrono says and be done with it.

The bullet does indeed start to slow down the nano second it emerges from the muzzle. Plain, simple physics, and always remember: "The Laws of Physics are Strictly Enforced".

[Jim White]

To all,

This website is pretty good and it takes into account the muzzle distance. When you get there click on "trajectory".

HTH,

http://www.jbmballistics.com/calculatio ... ions.shtml

[adam]

Thanks for your help gents I hope to settle on a final load soon !!!!