Other Newbie artemis p15

[pd#1]

Hi im a newbie too All this iv bought an artemis p15 177 and the velocity dosent seem to be giving out that much it's a brand new rifle is there anythink I can do to make it the sub 12 I thought it would be. Many thanks for any help and advice in advance paula

 

[Neu]

Do you have a chronograph? If not it's hard to guess what it is shooting at. If so what is it currently at? If not you will need to get one for tuning purposes.

 

[JimD]

I agree with Neu, the OP needs to give us some data for us to be able to help. About $20 will get you a very serviceable chronograph. Get one, fill the gun to 150 bar or so and shoot any 177 pellet you have through it until the velocity falls. Note the pressure. You reg is set a little above that pressure. Tell me what weight pellet you shot, the velocity it went before it went down and the pressure at which it went down. Lastly tell me what you want the gun to do differently. If you will do these things I or others will help you. If you do not tell us these things we can't do much.

 

[pd#1]

Yes i do have a chronograph I used crosman 10.5 grain pellets it started out doing 685.7 ft/s 10.96 ft/lb in this sort of range and when pressured dropped it dropped to in the 500 s ft/s and 8.32 ft/lb, I just want to have it at 12lb and thankyou for your time

 

[JimD]

Thanks for that information. Do you know what the pressure was at on the gauge when the velocity was maybe 20 fps lower than before? That would be very helpful to see where your regulator is set.

But regardless, the first thing to try is increasing the hammer spring and see what happens to velocity. There is a screw on the back of the air tube that lets you adjust how hard the hammer hits the valve. Try turning it clockwise 1 half turn and record the velocity. If it goes up try another half turn. Keep increasing until it stops going up. You probably don't want to stop at the highest velocity you get. Usually you turn the banner screw enough to reduce velocity from the peak by 3 to 5 percent. But it won't break the gun to stay at the peak.

If the velocity from adjusting the hammer spring is not high enough you can raise the regulator setpoint. But that is harder to do. But I can tell you how.

 

[pd#1]

Thanks for that information. Do you know what the pressure was at on the gauge when the velocity was maybe 20 fps lower than before? That would be very helpful to see where your regulator is set.

But regardless, the first thing to try is increasing the hammer spring and see what happens to velocity. There is a screw on the back of the air tube that lets you adjust how hard the hammer hits the valve. Try turning it clockwise 1 half turn and record the velocity. If it goes up try another half turn. Keep increasing until it stops going up. You probably don't want to stop at the highest velocity you get. Usually you turn the banner screw enough to reduce velocity from the peak by 3 to 5 percent. But it won't break the gun to stay at the peak.

If the velocity from adjusting the hammer spring is not high enough you can raise the regulator setpoint. But that is harder to do. But I can tell you how.

 

[pd#1]

I'm sorry I no longer have those readings, but I would appreciate it if you could help me how to increase my voloicity that would be great

 

[Neu]

I'm sorry I no longer have those readings, but I would appreciate it if you could help me how to increase my voloicity that would be great

Is it a sub 12 ftlbs gun to start with? If it is you are more then likely running into the max air that the valve will allow. If that's the case you may have to go with lighter weight pellets. To increase the hammer spring tension there is an Allen screw located at the back of the breech just above the stock. To increase reg pressure you will need to degas and disassemble the rifle.

 

[JimD]

pd#1,

I see your profile says you are in the UK so this is probably a 12 fpe limited rifle you are trying to tune. You got to essentially 11 fpe with the hammer spring using 10.5 grain pellets. If you used a heavier pellet your fpe would go up. 10.5 are on the heavy side of 177 pellets but not the heaviest available. My guess is your gun is tuned to 11 fpe so that if you use a heavier pellet you will not exceed 12 fpe.

I have not examined the valve in a 12 fpe gun but the apparent fact that you can buy a "high power" valve is consistent with the port from your valve being deliberately made smaller than I am familiar with. If so, raising the regulator will have much less effect. The smaller outlet hole of the valve is there to choke off air and it will do that regardless of the regulator pressure. I don't know if your regulator is also different from what I am familiar with to also prevent you from increasing it and thereby becoming "illegal", exceeding the 12 fpe limit.

If you have a permit for a >12 fpe gun I can tell you fairly simple ways to raise the fpe of your gun to 18-19 fpe. But if you do not have a permit, I think you should be happy with your 11 fpe gun. It is pretty hard to reliably tune a gun closer than 11 fpe to a 12 fpe limit and never go over. Higher ambient temperature will raise your fpe, for instance. So it is a good idea to not try and get too close.

Jim