how much power for 10 metre paper targets?

[johnyjohnjonno]

how much power in fps do you think is needed for 10 metre shooting?
i've just got a tau brno b96 which works off the little co2 powerlets, it's nicely balanced, got a fantastic trigger and i'm well pleased with it .
but when i shoot it's jumping a bit and looking at the dents in the backstop it's shooting more powerfully than my old pistol , the pellets are more mashed up aswell.
i havn't chronographed it yet , but how much fps is needed , i don't intend to use it for anything but 10 metre paper targets?
if it's overpowered which is causing the flip could it be turned down easily?
your opinions will be appreciated
cheers
johno

[bullbarrel]

Power isnt fps, its ft/lbs.

10 metre rifles are usually 6 ft/lbs

You'll need to do the maths to work out the fps required for your chosen pellet weight.

[johnyjohnjonno]

hi mate i know what you mean but my chrono works in fps , it's an f1 chrony , then i work backwards with a chart i've got if you know what i mean
john

[bullbarrel]

but fps is meaningless without knowing your pellet weight

[Hsing-ee]

You could adjust the power down to about 400 fps (7.8 grain pellet) - 2.8 ft/lbs. Any less and you might lose accuracy because of the amount of time the pellet spends in the barrel.

[johnyjohnjonno]

the weights are 7.35 gns , you've hit the nail on the head , what's the speed i should be looking for to reduce the flip , yet not be in the barrel any longer than needed
john

[bullbarrel]

FPS Grains ft/lbs
300 7.35 1.47
350 7.35 2
400 7.35 2.61
450 7.35 3.31
500 7.35 4.08
550 7.35 4.94
600 7.35 5.88
650 7.35 6.9
700 7.35 8
750 7.35 9.18
800 7.35 10.45
850 7.35 11.79
900 7.35 13.22

[Hsing-ee]

I think it is still 400 feet per second, which with these pellets is about 2.6 ft/lbs. The pistol weighs 2 lbs so the flip should be minimal, otherwise consider adding weight under the fore-end. With a 6" barrel the pellet will spend 1/800th of a second travelling through it, so you need to hold the sight picture and pistol still for 0.00125 of a second.

[Firestorm]

I think it is still 400 feet per second, which with these pellets is about 2.6 ft/lbs. The pistol weighs 2 lbs so the flip should be minimal, otherwise consider adding weight under the fore-end. With a 6" barrel the pellet will spend 1/800th of a second travelling through it, so you need to hold the sight picture and pistol still for 0.00125 of a second.

I'd like to see him measure that.

Russ

[johnyjohnjonno]

i've moved the weight thing back along the bar toward the breech end rather than muzzle , that seems to help , but i still think it's more powerful than i need , i'm going to chrono it later and see
john

[Hsing-ee]

i've moved the weight thing back along the bar toward the breech end rather than muzzle , that seems to help , but i still think it's more powerful than i need , i'm going to chrono it later and see
john

My Tau 7 had an adjuster to reduce the velocity. I think Pyramidair has a manual pdf you can download.

One of the cool things about the Tau is that it is powerful, and you can shoot the 20 and 25 meter rimfire targets with them and it's just as accurate.

[jonyb]

another option would be to clamp the pistol in a vise;protected of course!
and shoot groups at your required distance. adjust the power down until you get the best group without affecting your pistols operation.
i had the same problem with my steyr lp50. make a note of how many screw turns you have made,so you can return it to its original setting;espesially if you want to shoot 20yds or 25m.
this method can be used to tune your pistol to certain ammo,especially at the longer distance disiplines.

[harvey_s]

I think it is still 400 feet per second, which with these pellets is about 2.6 ft/lbs. The pistol weighs 2 lbs so the flip should be minimal, otherwise consider adding weight under the fore-end. With a 6" barrel the pellet will spend 1/800th of a second travelling through it, so you need to hold the sight picture and pistol still for 0.00125 of a second.

Not quite correct as the pellet does not start moving at 400 fps, it accelerates up to 400 fps by the time it leaves the muzzle....so afraid you'll have to stand still a wee bit longer

[eredel]

Makes a refreshing change to find a thread about tuning the power down on a pistol....

[Jim McArthur]

Makes a refreshing change to find a thread about tuning the power down on a pistol....

I can't really answer the original question, but I understand the Daisy Avanti 747 gets only about 365 fps, and it seems to do quite well at 10 meter paper punching.

Jim