American Airguns Blog
Wednesday, January 09, 2008
FT Max Power Limit
As a match director, one of the most time consuming things I do before a match is target preparation. The thing that makes this especially difficult is trying to set the targets for the wide range of power levels that the targets will be subjected to during a match. With guns varying in muzzle energy from 12-20 ft. lbs., it is a difficult task to get the targets to fall reliably for a low power rifle and not fall with a split or face hit from a high power rifle. I have seen 20 ft. lbs. rifles power down every type of target made with either a split or face hit. That can lead to an unfair advantage for a competitor using a high power rifle over someone using a lower power rifle.
Another issue is that higher power guns tend to beat up the target faces on targets that are placed at closer ranges. Over the course of a match, the smaller kill zone targets placed at closer ranges tend to get peened down to a slightly smaller size (even the Stoutenberg targets have this problem). That makes the target more difficult as the match progresses which creates an unfair situation for shooters who shoot the target later in the match.
A simple solution to these issues would be to drop the maximum energy level allowed at a Field Target match down from 20 to 15 ft. lbs. of energy. Using a ballistics program to calculate energy levels, velocities and trajectories for the various pellets used today shows that there is very little difference in the flight path of a heavy pellet fired from a 20 ft. lbs. rifle and a lighter pellet fired from a 15 ft. lbs. rifle.
The trajectories of the pellets are very close. Using Crosman Premiers as an example, the 10.5 pellets fired at 20 ft. lbs. will drop about 2.07 inches at 55 yards with a 25 yard zero. The 7.9 pellet fired at 15 ft. lbs. will drop around 2.27 inches at 50 yards with a 25 yard zero. The difference is about 1/8th of an inch or about one-two clicks.
The wind drift isn’t significantly different either. Using the same example as above, the 10.5 Premier will drift about 2.18 inches at 55 yards in a 5 mph 90 degree wind while the 7.9 will drift about 2.6 inches. That is less than half an inch more.
The 15 ft. lbs. velocity limits for various pellets would be:
Crosman Premiers 7.9 925 fps
Crosman Premiers 10.5 800 fps
JSB Express 7.87 925 fps
JSB Lites 8.44 895 fps
JSB Heavies 10.34 810 fps
Approaching this with a match director’s point of view, it is my belief that lowering the power lever from 20 to 15 ft lbs would facilitate the maintenance and setup of targets. Reducing the energy differential from about 8 ft lbs. (12-20) to about 3 ft. lbs (12-15) would allow the targets to be setup to perform more consistently with less wear and tear on the targets during the match. With all the rifles being closer in power, there would be less of a chance that one rifle might split a pellet and take down a face while another rifle won’t.
The 20 ft lbs limit was set many years ago based using airgun technology that is now nearly 20 years old. Perhaps it is time for the Field Target community to take another look at the power limit through 20 years of experience and see if there is a smarter and fairer way of doing things.
Another issue is that higher power guns tend to beat up the target faces on targets that are placed at closer ranges. Over the course of a match, the smaller kill zone targets placed at closer ranges tend to get peened down to a slightly smaller size (even the Stoutenberg targets have this problem). That makes the target more difficult as the match progresses which creates an unfair situation for shooters who shoot the target later in the match.
A simple solution to these issues would be to drop the maximum energy level allowed at a Field Target match down from 20 to 15 ft. lbs. of energy. Using a ballistics program to calculate energy levels, velocities and trajectories for the various pellets used today shows that there is very little difference in the flight path of a heavy pellet fired from a 20 ft. lbs. rifle and a lighter pellet fired from a 15 ft. lbs. rifle.
The trajectories of the pellets are very close. Using Crosman Premiers as an example, the 10.5 pellets fired at 20 ft. lbs. will drop about 2.07 inches at 55 yards with a 25 yard zero. The 7.9 pellet fired at 15 ft. lbs. will drop around 2.27 inches at 50 yards with a 25 yard zero. The difference is about 1/8th of an inch or about one-two clicks.
The wind drift isn’t significantly different either. Using the same example as above, the 10.5 Premier will drift about 2.18 inches at 55 yards in a 5 mph 90 degree wind while the 7.9 will drift about 2.6 inches. That is less than half an inch more.
The 15 ft. lbs. velocity limits for various pellets would be:
Crosman Premiers 7.9 925 fps
Crosman Premiers 10.5 800 fps
JSB Express 7.87 925 fps
JSB Lites 8.44 895 fps
JSB Heavies 10.34 810 fps
Approaching this with a match director’s point of view, it is my belief that lowering the power lever from 20 to 15 ft lbs would facilitate the maintenance and setup of targets. Reducing the energy differential from about 8 ft lbs. (12-20) to about 3 ft. lbs (12-15) would allow the targets to be setup to perform more consistently with less wear and tear on the targets during the match. With all the rifles being closer in power, there would be less of a chance that one rifle might split a pellet and take down a face while another rifle won’t.
The 20 ft lbs limit was set many years ago based using airgun technology that is now nearly 20 years old. Perhaps it is time for the Field Target community to take another look at the power limit through 20 years of experience and see if there is a smarter and fairer way of doing things.
