Chrono Distance.

[Cedric 132]

Anyone know what the recommeded distance from the muzzle for a chrono - rimfire and air rifle?

[andyf 144]

I set my chrono up on a camera tripod as high as it will go, such that the 'sky screen window' is about 3 feet off the ground,

I fire the rifle (or whatever) from no more than 2 feet away directly in the middle of the arched portion.

Be careful of course to ensure the fired bullets are shot into a safe backstop i.e. a firm but absorbent bank of mud or sand

without big rocks or other hard stuff that could create richochets or splash bullet fragments back into you or near bye personnel.

So it's 1 foot to 2 feet away, clearly an airgun doesn't have any muzzle blast but a 300 Win mag does (oh yes), so if your going

to chrony a big bore 2 feet min, maybe 3 feet.

AF

[Deker 3,491]

.......and be even more careful when you start to get curious about downrange energy!

[Cedric 132]

Deker - have you shot a chrono ???

[BlackStreak 498]

With center fire rifles you need to be about 20 feet away from the chronograph. The chronograph needs to be level and you need to be shooting level with it. The chronograph being level and your rifle being level with it and shooting straight through it will give you a fairly accurate reading. Both of my chronographs suggested that the sun be over head and not on the horizon. Better on a clear day too. I believe the rule is for every foot away you are from the Chronograph, you add 2 fps to the reading.

Common sense will take you a long way when shooting through a chronograph with a center fire rifle. A small 22 hornet you would not need to be back away from the chronograph the full 20 feet. On the bigger side of things, if shooting a 338 Lapua through it, you will need to be back the 20 feet. Just add 40 fps to the reading when 20 feet away. Distance away starts at the muzzle of the rifle.

I realize the question was about air rifles and rim fires but I thought you might find this information helpful or useful later on.

Dean