I'm new to the 50 BMG & want to do some reloading / develop some loads.

Due to the sizable projectile & associated muzzle blast, what distance is safe to place the chronograph from the muzzle?

Don't want to blow any parts off my equipment.
Thanks for any advice you can provide.

10 to 15 feet is enough. But my crono was acting strange till I learned that I had to put it under the bench out of the blast. The blast caused the plugs in the jacks to rattle and make and break contact. But I am having no more problems once I put it under the bench out of the blast. Frankly I dont have to use the sun screens. Seems that fat .510 bullet cast enough shadow.

I borrowed one from somebody at a HTFS earlier this year. It was sunny and had it set about 5 feet in front of the muzzle. The readings were right around where they should have been.

Thanks, I just wanted to be sure so I didn't break it.

Now here are some fast rules.

1) remember your barrel is about 3" lower that your scope. 2) I set my rifle up with something under the stock so rifle is pointing at the bullseye. One I have the sensors set-up and I eye ball down above the sensors for both level in relationship with the barrel and then I crank them down about 3 inches (using camera tripod). Then I go back to bench and eye ball it down the barrel both sides to confirm that the sensor are in-line and below the barrel a bit. If you do use the sky screens. Again I stand about 10 closer to the targets and eye ball it back to the rifle.

I have not shot my sensors, but have twice cut one of the supports and once I creased it can took some epoxy and tongue depressor and fix it. Those are cheap. but the senors cost some.

I saw someone shoot their chronograph before.
I had to bite my lip not to bust out laughing, but I'm now extra careful not to do the same;

Just because the scope sees a clear path, the barrel may not.

I have one of them fancy (not) Pact units. The electronics are in a separate box. Seen one of them that has it all built in to the crono. Guy shot out the display, electronics and sensors. Had to replace the whole wad. With a unit with the display and electronics at the bench the cost of the sensors is all I have to pay to replace it I get unlucky.

I prefer to set up with front of unit (end facing you) 15 feet ahead of end of barrel. Mount on a serious tri-pod weighted to prevent tip-over.
I use a black Sharpie to paint the projectile to enable the sensors to better see it. It helps for more consistent readings.


I have a used chrono for sale cheap - with the optional 0.510" diameter hole all the way thru it.
Be sure to allow for center of bore to be about 2.5" under line of sight.

Having to buy two chrono units is not cost effective!

I have mine mounted on my camera tripod.  It works pretty well & is easily adjustable for height.

I'll try 15ft... just didn't want to watch it blow over when I pulled the trigger.

OldmanFCSA, I just joined the FCSA forum.  Is there a lot of info there once you are a paid member?
There is not much for guests that shows up on their forum.

I use 10' for all my crono work. I also remove the bolt on the bolt guns and double check im not gonna hit the crono. A laser bore sighter has been an idea i have been wanting to try but havent bought one yet.

Sorry, the Visitor Forum just plasin SUCKS, just as much my fault as it is yours now. I should frequent it more, but am on too many Forums the way it is.

As for information, its there, but the SEARCH function sucks royally. Even tho we "oldtimers" push for new members to use the Search Function, we understand its failure and your need to re-ask the exact question we've already answered many times before.

As for your camera tripod, try hanging a weight (sandbag, lead weight, rock) under tripod to add stability.

And I welcome you to PM me on the FCSA Forum, I will try my best to answer your questions. Pl,ease read my topic called PAIN to better understand me.

OldmanFCSA, Thanks for the info today... nice talking with you.

Can't wait to get started with all of this.

I always leave the two rods in the shape of a V with the light diffuser on the top of them when I shoot.  I also have 2 marks 3/4 of the way up the V where I put the crosshairs of my scope across them.  It is about 6 inches above the sky screen and chronograph and helps prevent me shooting my chronograph..  Several years ago when it was getting late and my readings were having problems.  I thought if I shot a little closer to the sky screen I would get a better reading and sure enough it cost me a chronograph.   Since putting the black tape 6" up to put my crosshairs on I've not had any problems.  I have been watching the http://www.mylabradar.com/ chronograph that uses radar microwaves from behind the muzzle to read the speed of the bullet.  It is supposed to be able to read as far as 200 yards away from your shooting table.  The company that is developing it builds chronographs for military artillery. They are supposed to be ready for sale this fall or winter.  I like the idea and while not cheap I think I will get one.

That lab radar looks interesting. Will have to keep an eye out for this. IF they can keep it at 500 bucks, will probably get one. Its late coming out so sounds like issues popped up.