Tips on finding your guns power curve.
- Thread starter arubino19
- Start date
Fill to max recommended psi, start firing through chrony, number will:
Start high & go straight down -- Korean big power rigs & such a famous for this-
Or, it will start low, climb then drop again.
JUST some odd numbers picked for ex.
filled to a full 3,000psi my AA410 starts around 790fps ( too much air causing partial valve lock) at about 2,750psi it is at 900fps +/- 20fps extreme spread for right at 32 shots.
Cant recall ending psi but that doesn't matter, fill to about 2,800 fire 32 shots ( or so depending on game) and refill.
Anywhere you get a max 20fps extreme spread is your sweet spot.
?
John
Start high & go straight down -- Korean big power rigs & such a famous for this-
Or, it will start low, climb then drop again.
JUST some odd numbers picked for ex.
filled to a full 3,000psi my AA410 starts around 790fps ( too much air causing partial valve lock) at about 2,750psi it is at 900fps +/- 20fps extreme spread for right at 32 shots.
Cant recall ending psi but that doesn't matter, fill to about 2,800 fire 32 shots ( or so depending on game) and refill.
Anywhere you get a max 20fps extreme spread is your sweet spot.
?
John
Upvote 0
Fill your rifle's air tube to the manufacturer's maximum recommended pressure, usually 200 BAR. Some rifles need to be filled to 250 BAR or even to 300 BAR depending on how the manufacturer has purposely designed the valve system to operate; however, these are mainly pertaining to regulated rifles. Most unregulated rifles' maximum working pressure range is 200 BAR.
When shooting, make sure that the distance from the muzzle to the chronograph's front sensor is consistent throughout the entire recording session. Your goal is to get accurate and consistent data as much as possible. Also, if your rifle's power is adjustable, shoot it at the desired power level and leave it there. Throughout the entire string of shots you will very likely see muzzle velocities start off lower than peak velocity, then rise to peak velocity, then finally drop. (Hopefully, you are writing down or keeping track of the velocity of each shot) From here, you are going to decide for yourself how tight of a curve you want.
For the sake of giving an example, let's say you decide on a power curve that allows an extreme spread of 30 FPS. So, looking at your recorded data, look for a series of shots that begins before peak velocity and low velocity that overall yields a maximum of 30 FPS of variation. (It's easy to identify the curve if you've generated a line graph so that you can see the curve) Again, as a case in point in a power curve, you'd probably select a region in the curve that puts out a first shot of 830 FPS then rises to a peak of 860 FPS, then tapers back down to 830 FPS. Whatever velocity range you choose is your call, as long as the pellet shoots accurately at those velocities.
The next thing to do would be to determine the pressure level of the air tube that enables you to shoot your pellet at 830 FPS on the first shot and on the last shot as well. Depending on your gun, it could be from 200 BAR to 150 BAR or 180 BAR to 140 BAR, or it could be way off these ranges. Bear in mind that each gun will be different from another of the same brand and model in that it will give a similar extreme spread but at a different pressure range. Additionally, be aware that some unregulated guns are very efficient that they can yield 80 consistent shots while some can only give 40-50 shots. It's all about how well-designed the valve system is.
Good luck!
When shooting, make sure that the distance from the muzzle to the chronograph's front sensor is consistent throughout the entire recording session. Your goal is to get accurate and consistent data as much as possible. Also, if your rifle's power is adjustable, shoot it at the desired power level and leave it there. Throughout the entire string of shots you will very likely see muzzle velocities start off lower than peak velocity, then rise to peak velocity, then finally drop. (Hopefully, you are writing down or keeping track of the velocity of each shot) From here, you are going to decide for yourself how tight of a curve you want.
For the sake of giving an example, let's say you decide on a power curve that allows an extreme spread of 30 FPS. So, looking at your recorded data, look for a series of shots that begins before peak velocity and low velocity that overall yields a maximum of 30 FPS of variation. (It's easy to identify the curve if you've generated a line graph so that you can see the curve) Again, as a case in point in a power curve, you'd probably select a region in the curve that puts out a first shot of 830 FPS then rises to a peak of 860 FPS, then tapers back down to 830 FPS. Whatever velocity range you choose is your call, as long as the pellet shoots accurately at those velocities.
The next thing to do would be to determine the pressure level of the air tube that enables you to shoot your pellet at 830 FPS on the first shot and on the last shot as well. Depending on your gun, it could be from 200 BAR to 150 BAR or 180 BAR to 140 BAR, or it could be way off these ranges. Bear in mind that each gun will be different from another of the same brand and model in that it will give a similar extreme spread but at a different pressure range. Additionally, be aware that some unregulated guns are very efficient that they can yield 80 consistent shots while some can only give 40-50 shots. It's all about how well-designed the valve system is.
Good luck!
Upvote 0
I thank the OP for asking this very question as I'm new to the sport also and just got my Chrony Pro out of the basement,haven't used it since I was building Arrows for my Crossbows and now I have a reason to use it again.
Thanks for the info too.
Thanks for the info too.
Upvote 0