Efficiency

[digi]

hi guys

i just got a PTP Micromag with a ReTro valve. currently only getting about 500 shots off a 68ci/3000psi tank. is this normal? what can i do to get more shots out of this baby?

digi

[KC]

Should be getting 680 from the basic 3000psi = 10 shots per CI. Thats not a dry fire number is it? When you dry fire an automag its less efficient then if you shooting paint.

[mr doo doo]

digi, you are around the correct estimate. when i used my cousins PTP micromag (the RT one) i got around 500 shoots with a 68 ci 3000 psi tank. it sucked a lot, but who cares, its a mag .

[ThePixelGuru]

When you dry fire an automag its less efficient then if you shooting paint.

Really? Never heard that before. Why is that? Wouldn't it just put the same amount of air out the barrel regardless of what's in the chamber?

Anyway, your best bet for efficiency is an efficient barrel. Check out Tom's Tech Tips about barrel efficiency. You want a barrel with about 8-10" inches unported length, and if it does have porting make sure it's only for an inch or two. If you can, try out a lot of different barrels without changing your velocity. The one that shoots hottest will give you the best efficiency (once you dial the velocity back down).

[pierce]

[QUOTE=ThePixelGuru]Really? Never heard that before. Why is that? Wouldn't it just put the same amount of air out the barrel regardless of what's in the chamber? :confused It's true try it. That's why barrel to ball match will give you better gas milage.

[hobo in my trunk]

[QUOTE=pierce]

Really? Never heard that before. Why is that? Wouldn't it just put the same amount of air out the barrel regardless of what's in the chamber? :confused It's true try it. That's why barrel to ball match will give you better gas milage.

This is false. Regardless of whether there is a ball present in the chamber or not the same amount of air will be used. Anything past the on/off valve (in the valve assembly) is going down the barrel, a ball being there (or lack of) won't affect this at all. If you leave the velocity the same you will get the same number of shots with paint as you would without (if done on the same day/close to the same time...same atmospheric conditions).

And the reason why you get better efficiency with a good barrel/paint match is because with a good match you don't have to waste extra gas to push it down a barrel with gaps for air to get past or cram it down a barrel that creates too much friction (too small diameter). By decreasing the velocity adjustment you are using less gas. Again, same number of shots with mismatched barrel/paint as with a good match as long as the velocity screw is left alone (note that the measured velocity will be less with the mismatched barrel/paint if the adjuster is left untouched).

[questionful]

Well, doesn't the boltspring push the bolt back before all of the pressure is vented? You can see this when you turn your regulator down really low. If a ball is in the chamber, maybe it keeps more air from being vented?

[pierce]

Well if you don't believe me, i don't care. That's all i got to say about that.

[SnareTan]

[QUOTE=hobo in my trunk]

This is false. Regardless of whether there is a ball present in the chamber or not the same amount of air will be used. Anything past the on/off valve (in the valve assembly) is going down the barrel, a ball being there (or lack of) won't affect this at all. If you leave the velocity the same you will get the same number of shots with paint as you would without (if done on the same day/close to the same time...same atmospheric conditions).

And the reason why you get better efficiency with a good barrel/paint match is because with a good match you don't have to waste extra gas to push it down a barrel with gaps for air to get past or cram it down a barrel that creates too much friction (too small diameter). By decreasing the velocity adjustment you are using less gas. Again, same number of shots with mismatched barrel/paint as with a good match as long as the velocity screw is left alone (note that the measured velocity will be less with the mismatched barrel/paint if the adjuster is left untouched).

Wouldn't the ball being pushed out the barrel slow down the escape of air a little? Thus when the valves do close after the cycle there is more air left in? I doubt it'd be that significant of a difference, but a difference non the less.

Tan

[questionful]

[QUOTE=SnareTan]

Wouldn't the ball being pushed out the barrel slow down the escape of air a little? Thus when the valves do close after the cycle there is more air left in? I doubt it'd be that significant of a difference, but a difference non the less.

Tan

That's exactly what I said.

[sdlm_]

hi guys

i just got a PTP Micromag with a ReTro valve. currently only getting about 500 shots off a 68ci/3000psi tank. is this normal? what can i do to get more shots out of this baby?

digi

It seems lower than mine, I get about 2100 shots off a 114/45 outputting about 900-1000psi on my E-mag valve, about 1900 shots with my level 10 installed. Which puts the mag frankly in the pretty good efficiency category. My Angel gets about 16-1800 my shocker gets 15-1700shots........... I think you should be getting about 650-700 shots if my efficiency is an indication however, maybe I just have really good seals or something.

[chettacheez]

On a 68/3000 I get 4 pods and a halo, so about 720-740 shots.

Xvalve
ULT 4 shims
Predator hyperframe dwell at 6 ms
Dynaflow @ 900psi
LVL 10 second smallest carrier/red spring
deadlywind whisper/ .684
280 fps

[athomas]

[QUOTE=hobo in my trunk]

This is false. Regardless of whether there is a ball present in the chamber or not the same amount of air will be used. Anything past the on/off valve (in the valve assembly) is going down the barrel, a ball being there (or lack of) won't affect this at all. ...

Actually, in a mag, there is residual pressure left in the chamber after a shot is fired. In a level 10, it is even higher than the level 7's. Firing with a ball in the chamber creates backpressure which restricts the airflow. Firing without a ball in the chamber allows more air to dump out of the chamber before the bolt returns, thus making it more inefficient to dry fire.

[Spider-TW]

^^

The first time I tuned a lvl 10 I thought I had a leak somewhere because my tank went dry long before I was finished toying with it.

Same problem toying with a reactive trigger or a pneumag, always running out of air (sniff). I get more mileage when I wait for paint.