Ive used one of these great chronoscopes before on a rifle but when i checked the site it stated "not suitable for CO2 pistols,
I gave them an email to ask why and got a very prompt and helpful reply from the owners..ive copied below
"It's the barrel residue from the previous shot coming out in front of the pellet that is the problem.
First shot, with a residue free barrel is okay, subsequent shots read slow.
Usually associated with the oily Crosman CO2 cartridges.
To test for it, put masking tape over the cb-625 entrance and shoot through it.
Anything coming out in front of the pellet cannot get through the tape.
If the tape makes no difference you do not have the problem.
If the tape makes it read a lot faster then you would need to change the tape between shots which is a pain.
best"
good advise and i will be using one once ive made a few changes to my 22xx
PS IVE NO CONNECTION WITH THE COMPANY WHATSO EVER
IDK but it seems if your 3 to 5 feet away it wouldn't matter. Who knows???
I never shot a 7" 2240 through my chrony F-1, but a friend got a new one, and we could not get much (in fact one reading) at 2-3 feet. The muzzle blast was really blowing the light-weight cardboard shield. I have shot 14" 2240's and 10" 13XX's with good results at 2 feet from the muzzle.
I shoot everything at my pro chrono with no shield from 3-4 feet. Get consistent readings. Never had an issue.
beejwest,
By shield I mean shielding the sensors from extraneous light from the side with very light-weight poster paper - using indoors - difficult light conditions. And as I understand it, a 2240 with stock 7" barrel seems to spew a lot of CO2 particles. I didn't think to back up a small amount until he left - and there really isn't enough room anyway. Reconsidering the space it may have been less than two feet. :)
Since the Combro is attached directly to the end of the barrel, it's an issue with CO2. Using the tape shield is a great idea. I don't have any CO2 guns but a freshly oiled gun will sometimes give a few bad shots initially.
Love mine btw.
JMJ
I didn't know the Combro was attached at the barrel! ??? Crazy! I have the light kit for the digital pro, and it works flawlessly inside!
I made an adapter for my Combros by taking a 5/8" dowel and boring a 7/16" hole down through the center and then adding a nylon thumb screw for securing it to the barrel. This gave me some clearance between the exiting CO2 and the beginning of the chrono. Works great.
Carl
Quote from: beejwest on May 28, 2016, 01:01:46 PM
I didn't know the Combro was attached at the barrel! ??? Crazy! I have the light kit for the digital pro, and it works flawlessly inside!
You & me too.
yep it fastens right on the barrel end...and the company states in its warranty words to the effect" a hole shot in the scope does not comply with our faulty goods returns policy"
I dont know if its made in the UK but the company who sells em is here and is staffed by people who care it seems.I had one co -owned by 3 other fellas at work but now have lost touch with them so I will have to buy a new one.I would love to buy the fancy US models which look as if you are shooting through a pair of 1960's aliens antennas but they are expensive in the UK.
On the plus side its small enough to fit in the gun case and is always on hand to settle bets/arguements
Quote from: quickster47 on May 28, 2016, 05:22:55 PM
I made an adapter for my Combros by taking a 5/8" dowel and boring a 7/16" hole down through the center and then adding a nylon thumb screw for securing it to the barrel. This gave me some clearance between the exiting CO2 and the beginning of the chrono. Works great.
Carl
:-* Now that's cool ! :-*
Quote from: UKairgunner on May 28, 2016, 07:52:17 PM
yep it fastens right on the barrel end...and the company states in its warranty words to the effect" a hole shot in the scope does not comply with our faulty goods returns policy"
I dont know if its made in the UK but the company who sells em is here and is staffed by people who care it seems.I had one co -owned by 3 other fellas at work but now have lost touch with them so I will have to buy a new one.I would love to buy the fancy US models which look as if you are shooting through a pair of 1960's aliens antennas but they are expensive in the UK.
On the plus side its small enough to fit in the gun case and is always on hand to settle bets/arguements
That's a shame! The Digital Pro here only runs about $100 USD
yes the UK is expensive
The English channel kept Hitler and Napoleon at bay but it does make it easy for our government to impose high taxes
the 2240 sells for between £75-£90 over here...ugh(109-130 US dollar)
I bought mine through a Canadian company. $75ish shipped IIRC. Quickster. Great modification. I see you have the deluxe (translucent housing). Very nice. JMJ
JMJ