I would like to know if anyone can tell me if a spring airgun increases power due heat generated by repeated shooting, and if so by how mutch?
I would like to know if anyone can tell me if a spring airgun increases power due heat generated by repeated shooting, and if so by how mutch?
I'm no expert. But would think any possible gain/loss due to expansion of components as they warm would be lost as the gun is mainly made of metal - effectively a heatsink.
A few years back one of the mags ran tests (Jim Tyler?) on the effectiveness of seals at LOW temperatures, involving freezers etc. Took quite a drop to make any difference.
My 2p worth.
Bru
Last edited by laverdabru; 30-12-2020 at 10:20 AM.
Webley Mk3 x2, Falcon & Junior rifles, HW35x2, AirSporter x2, Gold Star, Meteors x2, Diana 25. SMK B19, Webley Senior, Premier, Hurricane x 2, Tempest, Dan Wesson 8", Crosman 3576, Legends PO8.
depends how tight the seals are at 'normal ' temps
if they re daft tight you'll lose power as things warm up and grow.
So little as makes no difference imho.
Personally, I am in favour of using a heat source on any springer.
Where I differ is my belief the heat source should continue till it melts terminator style
In a battle of wits I refuse to engage with an unarmed person.
To one shot one kill, you need to seek the S. Kill only comes from Skill
Yes, this. As Jim has explained to us in his excellent articles on the subject, it's all to do with the differences in coefficient of expansion of different materials at different temperatures. The most often used piston seal these days is the synthetic "parachute" design and it expands / contracts more due to different temperatures than the steel cylinder. So if, as above, we had a seal that fits on the tight side at "normal" temperatures, as the temp increases the seal expands more than the cylinder causing higher friction and hence, potentially, robbing power. As the temperature drops, this same seal will exhibited less friction and the gun can then deliver more power.
If the seal is a very loose fit, however, its contraction in size with very cold temperatures could marginalise its sealing capability and reduce power. And it has been known to happen to at least one person who I know on this very forum where with a very severe drop in temperature the rifle failed to shoot a pellet.
Other factors can also have an influence. Jim has covered how temperature shift affects power on different designs a few times now, including in this month's magazine covering how the PCP is affected.
THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
NEXT EVENT :- August 3/4, 2024.........BOING!!
THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
NEXT EVENT :- August 3/4, 2024.........BOING!!
Done 3 different guns over the years , Hw97 centenary , First couple of shots after 11 years, 11.4 about 7 years later same results 11.4 and the same again a couple of weeks back.
Webley stingray Express, Had little use when bought in about 2000/2001 about 11.0 years later it was up around the 11.4 , Putting through the skan again a while back and it's now on 11.8 ,
My old hw77 had a kit fitted and kept in increasing in power , Unfortunately that is now in bits, Still deciding on what Finnish I want on it has I had it camoed years ago,
I think pellets of today make a big difference to the guns shooting readings, One thing for sure you will find a Springer more consistent with less fps spread than you will of a PCP gun , Even regged pcp guns will not match most springers with the variance, You can get some surprising outcomes if you got time on your hands.
Yes, it's always advised to check the power output periodically anyway for "health check" and legality reasons. Also nice to see the power rise as a springer breaks in.
However, the thread is concerned more with whether the output varies as the mechanicals warm up, mainly through repeated rapid use but also (and this has a much bigger influence on output) on the output in different ambient temperatures.. Before Jim's enlightening work, many might argue that the springer's power was reduced in colder conditions due to the viscosity increase of any lubricating grease. His work has proved the opposite. A lot depends, of course, on the individual gun's set up, especially the piston seal fit.
I seem to remember that gas rams behave pretty much the same as springers.
PCP power output drops as the ambient temperature drops. Better to acclimatise fully when charging etc. But they're inferior to springers anyway! (@Steyr - ).
And the poor old CO2 powered guns definitely suffer when those temps drop.
THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
NEXT EVENT :- August 3/4, 2024.........BOING!!
Here's a chance to contribute very positively and find the answer you want for the rifle of interest.
All you need is a tin of pellets and a chrono (preferably which records MV string results for long strings) or failing that a literate assistant! Oh and some elbow grease!
Set yourself up with a reasonable backstop and fire a string of pellets as fast as you can over the chrono recording each MV reading! Then plot the readings and look for any trend since the shot to shot variation for good pellets and a good barrel and a well set up rifle will be between 2 and 10fps anyway. There are so many contributing factors which are affected by temperature (many stated already) but you appear need quantified results and I for one am all for that! Happy to help with any analysis (e-mail in my profile!).
It would be a very useful contribution to knowledge and maybe start a craze so we can get very many rifle samples quantified!
Power to your elbow and stay safe and well into the New Year.
atvb
David
Last edited by TopDog; 30-12-2020 at 03:21 PM. Reason: addition
May today be the best day of your life and all your tomorrows even better!!
No. The heat transfer from the hot air is a few Watts, I seem to remember 20- I worked it out, but over a very short period of time. It is a fraction of a Joule/ ftlb so don't worry about it. The heating due to friction between the moving surfaces will be higher. Airguns are pretty big chunks of metal so it would take a lot of energy to warm it up.
Not sure if Jim has stuck a springer in a freezer to see if they work at -20.
thanks,seems most of you agree it makes little difference. I will plink away all I like without worry , thank you all.
There can be a small but noticeable effect based on the rate of shooting. In essence shooting quickly warms the seal material slightly and this can lead to POI changes vs shooting more slowly.
“We are too much accustomed to attribute to a single cause that which is the product of several, and the majority of our controversies come from that.” - Marcus Aurelius