Does it being hot , really hot affect how a springer shoots

[threex4]

I'm getting ready to tune my HW 30,. Have chrony it before and readings were low, so low is the reason it might need the tune. well today, its 99 with a heat index of 108, I'm shooting under a covered patio with the chrony in the sun getting good light. Pellets used,
 these are all light pellets.

gamo match avg 625,
cpl avg 591,
beeman gold hp avg 665 with one at 906? ,
Cr points 600 avg, with one a wopping 732 ??.

   the heavy's
cph, 590 avg ,
beeman kodiak ehd match, 560 avg.
now shooting these same pellets before , when it wasn't quite so hot, I never avg anything higher than 550 and that was with the cpl.
Now the gun smoked really bad today, and some of the shots,  there was so much smoke ,it looked like a rim fire.
So does the heat really affect the way a springer shoots or what.
does the gun still need a tune or should I wait till its cooler ( less than the 99/ heat index 108 LOL) to chrony and compare the difference once more.
Note: This is not a new gun, it is a older model HW with the rekord trigger. I don't know what the last owner did to this gun, I have only owned it for 6 mts and it has smoked  after each shot since I've had  it.  I'm told that these guns had leather seal, so either the seal is saturated with oil/moly , that may or may not have been due to the heat.  
 

PV=nRT

The famous ideal gas law, if you took chem you can start crying now for my bringing it up.

So, if you follow me looking at the equation, if you hold volume constant, and R and n are constant and you raise T, P has to go up.

I would assume that greater pressure translates to greater fps.

How much pressure is too much pressure I have no idea. That's a question for the pros on the site. Hopefully they will chime in.

[Gene_SC]

I was told that oil in the chamber of a springer is not good. It may be leaking past the seal. Also I think it causes detination with the hammer, which is very hot from compression. Could of crystalized a seal or somethin.

I was never that great in science but I do know this. Metal, wood, plastic, and even air expands under higher than normal conditions as well as contracting under cold conditions. But I do not know how much it would effect a springer..

I do think you may have a problem if you continue to see smoke coming outa your barrel when you shoot....

Gene

[vinceb]

It doesn't work that way.

Pressure goes up ONLY when the gas in confined in a vessel of fixed volume. That is not the case when atmospheric temperature goes up.

What does happen is that the PRESSURE stays relatively constant, so the volume (for a given air mass) increases. This is another way of saying that warmer air is less dense than cooler air, less density means less working mass for the spring/air mechanism. So it is entirely possible that a springer will shoot slower on a hot day.

I was thinking more of air already in the chamber, then heat it, rather than taking in pre-heated air then compressing it.

The question, then, is why would he see an increase not a decrease? Reduced drag from less dense air?

[vinceb]

He's obviously getting some dieselling. His occassional "fast" shots attest to that, and he is likey getting lesser amounts on other shots. If you notice, his velocity with CPH is virtually the same as his velocity with CPL. That just ain't gonna happen unless he's getting some help from burnng lubricants.

Hot weather will increase the likelyhood of dieseling simply because the baselline temperature starts out closer to the ignition point of the "fuel", and it takes less of a temperature rise to go "BANG!".

In addition, there is also the possibility that his gun is experiencing less friction in hot weather, and that can have a tremendous effect on a gun, especially with a relatively high-friction leather seal. Wet lubricants tend to go lower in viscosity at higher temperatures. And since the compression tube - to - piston clearance gets slightly larger at warmer temperatures, he might have less drag if the seal is a smidgen tight to begin with.

Another possibility is that the leather seal is more pliable in warmer weather, and seals better.