Prochrono questions

[wildlifeclyde]

I just purchased a Prochrono and have enjoyed learning to use it. I've only shot handgun calibers over it so far: 380, 38spl, 40, & 44mag. I've got my chronograph set up at apx. 10 yards out. I'm trying to develop a load for the 380 and 40 so I've shot mild to hot loads of each with various powders.

The 38spl is a light load using clays. The 44mag is loaded with H110 for a full power load out of a 7 1/2in RBH.

The 380 and 40 I'm using various powders that are probably 30 years old, I don't know if that makes a difference or not but they seem to throw a lot of trash.

The screens are down in a slot and some of the trash has been getting in there. What is the best way to clean them off? a Qtip and some rubbing alcohol? I was wondering if I could put clear packing tape over the slot to keep the junk from getting in there and just wipe it off or replace it.

Do I need to move the Chronograph out farther, I feel like I have less of a chance of shooting it the closer it is. Is 10 ft to close for the muzzle blast from the 44mag?

I read a suggestion to replace the metal rods with wooden dowels so that when you shoot them they break instead of "twanging", I haven't gotten around to that but thought it sounded like a good idea. Any other tips anyone could pass along to a new chronograph user would also be appreciated.

 

[Galil5.56]

I will hold my ProChrono Digital chronograph upside down, and blow out the dust/junk off the clear plastic sensor covers. I can't see any harm with a very gentle cleaning of the plastic surfaces, but I would not use alcohol without knowing for sure that it would not cloud/harm the plastic... Maybe just a little distilled water applied to a barely damp q-tip?

I have used very clear tape over the sensors, and it seems to work OK w/o causing issues, but have not used it enough to say 100% for all situations that it will not cause issues. 10 yards is plenty far away, and one tip is to perhaps place a very thick piece of clear plastic in front of the unit, or even a block of wood if you don't care about seeing the results in real time if you are using gas checks... Had one take out a chronograph about 15 years ago from my .44 Mag.

 

[Walkalong]

I put my Pro Chrono at 5 yards, but I have not had to clean it, not once. I did get careless and shoot a rod once.

 

[mmorris]

I put clear packing tape over the openings on my ProChrono. Before I covered the holes, I cut a piece of tape about the size of the opening and applied it, sticky side to sticky side, to the tape that covered the hole. This puts a small unglued part of the tape over the sensor hole, and keeps the adhesive from attracting any debris that might get inside the case.

 

[1SOW]

For pistols, I put mine at 10+ feet, but I don't shoot heavy loads.

Never had any dirt other than using a soft cloth to wipe of the lens occassionally. It was shipped to me in a good cardboard box, where I store it before and after use along with the tripod that just fits. I carry it to the range in that box. I cut wooden dowels as back-ups for the screen rods, but SO FAR I haven't needed them.

 

[mmorris]

Use the wood dowels... Not metal rods

The wood dowels are preventative. A hit to the wood will cause less damage to the chrono housing than a hit to the metal rods. Waiting to use them until the metal rods are hit defeats their purpose.

I have discovered that wood dowels are also helpful in preventing damage when the tripod the chrono is on is knocked over :banghead:

 

[Ledhore]

I use wood dowels on mine also. I painted them flourescent orange and placed blue masking tape at the elevation where I want the bullet to pass over the sensor. Makes it easy to be very consistent when shooting over it.

 

[amlevin]

Soda Straws work great too. Just make a shot "peg" out of wood dowel or welding rod to fit in the holes, just long enough to stick up about 1" or so. Put a straw on it and go shooting. Works fine unless you need the screens on a super clear, sunny, day (which is a rare occurrence here in the PNW.

Straws are free if you just pick up a few "spares" when getting a meal at your favorite Fast Food joint.

 

[wildlifeclyde]

Oops, 10 feet on the Chrono, not 10 yards, we've had a sick baby the last week and regular sleep hasn't made the agenda.

Thanks for all the great ideas! The gas checks would not have been something I would have thought about being an issue, if I use them in the future, I'll be sure to take that into consideration. Moving the chrono to 5 yards isn't that much of a difference and may allow the powder trash to drop on the ground before it reaches the chrono.

When I get a chance, I'll shoot a couple of boxes of 38's over it with and without tape to see if it makes a difference, doing away with the sticky surface above the sensor is another great idea. The concern about dirty sensors may not be as big of a deal as I originally thought. I have read a few threads where folks were getting erratic readings from crud build up but that may happen over several years of use or dust from the shelf, i'll keep mine boxed when not in use. I noticed the powder junk and was afraid there was a lot more stuff landing there that was too small to see, and I didn't like having it all down a hole that wasn't very visible anyways.

Dowel rods are on my Lowes shopping list and I'll definitely swap them out. When the new contraption arrived, the little kid in me couldn't wait to use it straight out of the box. I think the paint and point of aim tape sounds like a great idea too.

Thanks again for all the great tips!

 

[mmorris]

Get soft wood dowels if you have a choice.

 

[Ridgerunner665]

I've shot 2 of those chrono's...and bought a 3rd. (they're good chrono's)

I put shipping tape over the sensors to keep the debris out, doesn't effect function and its a cheap easy fix.

 

[Hondo 60]

+2 on the wood dowels.
If you would happen to hit the dowel, a wooden one will just snap.
If you hit a metal one, it'll knock the whole thing over.