N/A Share of knowledge

[Emu]

This is logic. But I had not catch it up to now:

Irrespective of your bottle is 700 cc, along a shooting session, the lower the pressure in the bottle, the longer time it takes for the plenum to get refill.

So…..

In order to keep POI, you need increasing time among shots as pressure in bottle is decreasing.

Maybe it was obvious for all or you, but maybe one of you, learn it today, as my self.

 

[JaceSpace1369]

This is logic. But I had not catch it up to now:

Irrespective of your bottle is 700 cc, along a shooting session, the lower the pressure in the bottle, the longer time it takes for the plenum to get refill.

So…..

In order to keep POI, you need increasing time among shots as pressure in bottle is decreasing.

Maybe it was obvious for all or you, but maybe one of you, learn it today, as my self.

Oh the joys of pcp airgunning, thanks for the bit of knowledge.

 

[ctshooter]

I guess this would make sense as the lower bottle pressure pushing through the regulator would not open it quite as wide so air flow would be slower.

This does lead to another question - does it matter? What is the actual refresh rate in milliseconds of your regulator and how much does that rate change over bottle pressure? How much is this impacted with a small caliber versus a large caliber? How much does plenum size and output fpe play into rate changes?

In this instance I do not feel that a qualitative answer is sufficient. A quantitative test of the different refresh rates would need to prove this is something to be concerned about while shooting.

 

[Emu]

I guess this would make sense as the lower bottle pressure pushing through the regulator would not open it quite as wide so air flow would be slower.

This does lead to another question - does it matter? What is the actual refresh rate in milliseconds of your regulator and how much does that rate change over bottle pressure? How much is this impacted with a small caliber versus a large caliber? How much does plenum size and output fpe play into rate changes?

In this instance I do not feel that a qualitative answer is sufficient. A quantitative test of the different refresh rates would need to prove this is something to be concerned about while shooting.

I have a Wolverine .25 HR non HP.

It has a 700 cc bottle.

First 25 shots are extremely accurate. But I notice that after that the rifle started to become not so accurate.

Yesterday I went to my shooting stand to confirm if that was or was not true.

I started to notice lack of accuracy. Then I stopped shooting and begin to try to find the reason.

When I restarted shooting, them rifle started to hit exactly where I wanted at 88 yards.

Then I found that the only possible reason for the rifle to went back to accuracy was time among shooting.

So I started shooting with increasing time among shots and the rifle was perfectly accurate after 50 shots since refill.

 

[Vetmx]

I guess this would make sense as the lower bottle pressure pushing through the regulator would not open it quite as wide so air flow would be slower.

This does lead to another question - does it matter? What is the actual refresh rate in milliseconds of your regulator and how much does that rate change over bottle pressure? How much is this impacted with a small caliber versus a large caliber? How much does plenum size and output fpe play into rate changes?

In this instance I do not feel that a qualitative answer is sufficient. A quantitative test of the different refresh rates would need to prove this is something to be concerned about while shooting.

It is and it isn’t. Refresh time, the -4% velocity from full to refill can be issues for some and not an issue for others. I always say to inquiring minds that if you are happy with all your guns and they are “lasers”, don‘t go down yet another rabbit hole. Basically don’t go looking for an issue if one doesn’t exist. Because if you do, it might complicate what you once enjoyed.

 

[nervoustrig]

This does lead to another question - does it matter?

Definitely one of those "it depends" things. My experience has been that most regulators recover sufficiently in about 3-5 seconds. For most kinds of shooting that is plenty fast...by the time you've chambered another round and aimed carefully and squeezed the trigger, the pressure has long since recovered.

But there are a lot of factors at play that can tilt the scales, key among them:

• regulator design - a large orifice can replenish faster but the tradeoff tends to be poorer input regulation.
• power level - This one's pretty obvious. A gun producing 100fpe uses a lot more air than one producing 50fpe. The regulator will take longer to replenish a greater volume of air, all other things being equal.
• condition of regulator's valve seat - A worn seat will contribute to a longer time for the pressure to top out.
• pressure differential - This one is the basis of Emu's public service announcement, and for example a regulator asked to hold a 100 bar setpoint on a 300 bar fill has a tougher job than if it were only a 220 bar fill (pressure deltas of 200 bar and 120 bar, respectively).
• state of tune- heavy or balanced?
  • heavy - If a gun is adjusted with too much hammer strike in order to squeeze out the last little bit of velocity, it's going to be an air hog and take longer for the regulator to replenish,
  • balanced - If the hammer strike is set optimally (not too heavy, not too light), the velocity will not be affected as much by little pressure variations that emerge from the preceding factors.

And to complicate things, these factors can exist simultaneously to varying degrees. Not to mention the above is not a complete list but I think it captures the main ones.

 

[Headshots]

When I collect data with a chronograph I usually target shoot as well . I've never noticed a change in velocity until it falls off the reg.

 

[Vetmx]

When I collect data with a chronograph I usually target shoot as well . I've never noticed a change in velocity until it falls off the reg.

Balanced.