Chronographing BP guns

[Gbro]

I have Chronographed BP guns in the past and have not liked the results.
I would like to know if anyone here has experienced problems and found solutions.
Do patches mess up muzzle velocity results?
Dose the smoke cloud interfere with results?
How close is too close, How far away can one be before it isn't considered muzzle velocity?

A friend machined a .400 mold for Minie's and we are planning some tests on this bullet.

[sundance44s]

Your Crono needs to be 10 ft away from the muzzle ..and I always cover the read out in front with a piece of old canvas to keep the burning powder off the face.
I get real good consistant results this way .
And when friends what to shoot through my crono ..I tell`em you hit it.. you buy it ! ...LOL

[Raider2000]

Originally Posted by sundance44s

Your Crono needs to be 10 ft away from the muzzle ..and I always cover the read out in front with a piece of old canvas to keep the burning powder off the face.
I get real good consistant results this way .
And when friends what to shoot through my crono ..I tell`em you hit it.. you buy it ! ...LOL

I like your idea better than mine "piece of plastic sheeting infront of the read out" & yes I agree you need to be about 10 feet from the muzzle & I give my buds the same line you hit it.. you buy it!

[Gbro]

Thanks,
That is what I was looking for.
I need to replace one of my sky screen anyway, and i want to replace the steel rods with wood or something that might not damage the chrono. if a stick/rod is clipped.
We will be shooting through at 50 yards and there is a possibility of destruction.

Thanks again
Greg