Chronographing CO2

If you wish to make a donation to this forum's operation , it would be greatly appreciated.
https://www.paypal.com/paypalme/targettalk?yours=true

Moderators: pilkguns, m1963, David Levene, Spencer, Richard H

Forum rules
If you wish to make a donation to this forum's operation , it would be greatly appreciated.
https://www.paypal.com/paypalme/targettalk?yours=true
Post Reply
Clark
Posts: 4
Joined: Tue Mar 23, 2004 4:38 pm
Location: Boston, Massachusetts

Chronographing CO2

Post by Clark »

I have used a chronograph to evaluate CF reloads, but I have never used it with my CO2 pistol. Does anyone know if a chrono. can yield worthwhile info. for a CO2 pistol?
Bill177
Moderator
Posts: 271
Joined: Tue Mar 02, 2004 9:32 am
Location: Upstate NY

Chronograph testing on an AP

Post by Bill177 »

A chronograph is valuable in testing a Co2 airgun. You can test the velocity of different pellets, the same pellets at different temperatures, and adjustments made to the valve of the gun.

Be sure to log all your information for future use.
Mark Briggs
Posts: 583
Joined: Mon Mar 01, 2004 8:35 am
Location: The Frigid North - Ottawa, Canada

Important - Distance to Chronograph Screen

Post by Mark Briggs »

One important point to note when it comes to chrony'ing Co2 guns... The cloud of Co2 expelled from the muzzle can cause false triggering of the chrony if you're too close to the first skyscreen. To avoid this, make sure the chrony is a yard or so off the muzzle. In this manner I haven't had any trouble getting very reliable results with mine.
Clark
Posts: 4
Joined: Tue Mar 23, 2004 4:38 pm
Location: Boston, Massachusetts

Post by Clark »

When testing pellets, I have compared two things:
1. group dispersion, and
2. weight variance.
I have assumed that heavier pellets may travel a bit slower, but velocity is irrelavant as long as the pellets group well and do not tumble/ tear the paper. Just because velocity can be measured doesn't mean it is worthwhile. What is the point of chronograping a CO2 driven pellet?
Mark Briggs
Posts: 583
Joined: Mon Mar 01, 2004 8:35 am
Location: The Frigid North - Ottawa, Canada

Post by Mark Briggs »

In some jurisdictions muzzle velocity determines whether or not your airgun is or is not impacted by onerous gun control legislation.

On another front, chrony'ing your airgun gives you a good idea about velocity performance in terms of consistancy across pellet types, as well as consistancy across cylinder fill levels, temperature, etc. I've seen instances where there was very little correlation between grouping performance and consistancy of pellet weight. But a low extreme spread in velocity can have a significant impact on group size. Velocity is just one more variable that's helpful to characterize. But remember, some folks buy cheapo pellets, shoot them out of a rusty old pistol with plywood grips and shoot very well. It's a personal choice.


Mark.
Clark
Posts: 4
Joined: Tue Mar 23, 2004 4:38 pm
Location: Boston, Massachusetts

Post by Clark »

Now I am getting interested in using my chronograph on my CO2 pistol. Based upon Marks reply there may be a stronger correlation between pellet velocity and group size than between pellet weight and group size.

A chrono. may also be the best way to choose the optimum pellet diameter, i.e. 4.49, 4.50, 4.51 etc.

Has anyone tested these possibilities?
Post Reply