How close can you get to your chrono without error readings from being too close when shooting full power 10mm loads from ~5" barrels?
How far do you normally have your muzzle back from the first sky screen for general all around pistol round chronographing?
I use to work at 8' but now I work at 10' to 12'. I found that some powders need more room than 8'.
However bullet position over the screens, lighting and battery strength are all very important. That being said some bullets being very shiny can cause some miss reads, so blackening the bullets can also help.
Thanks The_Shadow. I've been setting up my chrono 10' away myself and was wondering how much closer I could get away with and still not have issues. I simply figured the closer I can be to the chrono, the less chance I have of ever taking it out with a bullet. Will you offer an example of a powder that required more than 8 feet? Was it just one powder? I'm going out with my chrono tomorrow if nothing changes in the mean time, and will probably play with distance a little bit myself.
It isn't the powder, so much. It's the velocity. If supersonic, the bullet will beat the muzzle blast. Subsonic, it won't. It's that simple. If you're shooting full power 10mm, and getting errors, you are getting 2 readings, with the second being the error (blast), or you missed the target window. I set back 10-12' for most, closer if I don't feel like walking that far. Less than 8' may have some issues with sub-sonic rounds. More than 12' with shotshell, is asking for trouble!
The type of chronograph makes a big difference too. My old Shooting Chronys were a lot more sensitive to distance than the Pro Chrono I have now. I usually just stand 5'-6' away from this one.
Two days ago I set up at 9' and all was well for 10mm loads ranging from 650-1600fps. Once I started shooting I never did toy with the distance any more. Next time out I'll set it up closer and see what happens.
I had mine set up about 7'. Worked fine for some powders, not for others. Moved back to 10' and had no issues.