temperature affecting P.O.I. in springers

[gurtwurz 792]

hi lads, i'm sure that while reading a recent thread that someone mentioned temperature affecting the poi with springers, particularly when getting them out the gunslip on a cold morning. since i'm returning to springer central after coming back to airgunning via pcp's the knowledge'd be mighty useful over the next 3 months or so!

 

anyone able to elaborate on this?

 

cheers, wurz

[Phantom 631]

I think the point of impact may change due to the shooter being cold (shivering).

 

I honestly cant see POI changing buy much indeed if and; however as the air is a little denser when cold over a longer distance it may slow the projectile down a touch?

 

Phantom

[mikeyblue 28]

Hi Wurz,

 

At the minute I only shoot a springer. I haven't noticed a change in POI from difference in temperature. I have noticed however a slight change from different firing positions. Eg, when i group kneeling or sitting FT position the pellet strikes slightly higher than prone!

 

regards,

 

Mikey

[gurtwurz 792]

same as,except i group slightly lower when kneeling after zeroing in in the prone position. i hadnt noticed any major changes when out in the frost this morning but i was kind of intrigued by what i thought i'd read earlier, but i cant remember what thread i saw it in...

 

cheers, wurz

[Nathan_R 10]

Hi Wurz,

 

A change in temperature will affect the elastic modulus of the spring slightly, but climatic changes in temperature will only affect it's performance by a fraction of a percent - too small to notice in the real world. A steel spring at -20 degrees C has an increase of only 0.5% compared to it's elasticity at room temperature.

 

As phantom said cold air has a higher density and will therefore slow the pellet but only by a tiny degree:

Dynamic pressure (which roughly equates to air speed) = (0.5 x air density x velocity)squared

The density of dry air at 30 degrees C is 1.1644 Kg/m3 and at -20 degrees C it is 1.3943 Kg/m3 so the overall difference in dynamic pressure due to atmospheric temperature will be so small as to make no practical difference.

 

I would say that the range of temperatures we encounter in the UK will make no noticable difference to the POI when using a springer, PCP's and CO2 rifles are a completely different kettle of fish though!!

 

Nath

[pianoman 3,587]

Hi Wurz

Fire 10 to 20 shots through your HW95 and get the oils and lubes around the internals warmed up and circulating at the start of your hunting session, you should be fine for the day after that. I get a bit of sluggishness with my HW80s on very cold days, and this seems to cure it.

 

Simon

[pest hunter 151 15]

The air gets more dence when its cold but will only effect over a very long range. Prob arround where the gun starts to bottom out. You should not hunt at this range anyway. Good luck

 

 

 

Ph1

[gurtwurz 792]

cheers lads, much appreciated.

 

@ simon, i think it might've been summat you posted earlier that got me thinking about it so cheers for that buddy, its getting pretty parky here at the mo!!

 

@ ph1, still not hunting at extreme range with the springer yet but ta anyway

 

@ tony and nath, cheers lads, hadnt considered air density at all!! thats an interesting line of thought tho, must be a bugger in extreme arctic conditions, especially if coupled with cold lube in the rifle springs. food for thought...

 

thanks again guys, wurz

[Phantom 631]

You planning on hunting some Reindeer up at the old fat mans place? HOHOHO

 

:11:

 

Phantom

[gurtwurz 792]

not quite tony lol, but we run an arctic survival course in sweden and i was considering taking the '95 if i do it, be interesting doing vermin control at -35 eh...

i reserve the garrotte for mr claus-next doors pressies looked nicer last year...

cheers, wurz

[major1 6]

i thought it would only change on a pcp put very sleighligh

[andyfr1968 772]

I've never noticed this on any of my springers ever but it's an interesting point.

 

I'm out this Saturday, all being well and I'm going to check the zero on my 90 tommorow indoors at my mate's brewery (really!!). at 25 yards.

 

I always have a few test shots before going hunting but I'll have an extra thorough check this time to see if I can tell even the slightest change.

 

I think just for the hell of it, I'll take my 52 along too and test that, the forecast's bloody cold for the weekend but my mate keeps his place at around 18 deg C so it'll be interesting to see if it affects either gun...

 

Cheers.

[andyfr1968 772]

I've never noticed this on any of my springers ever but it's an interesting point.

 

I'm out this Saturday, all being well and I'm going to check the zero on my 90 tommorow indoors at my mate's brewery (really!!). at 25 yards.

 

I always have a few test shots before going hunting but I'll have an extra thorough check this time to see if I can tell even the slightest change.

 

I think just for the hell of it, I'll take my 52 along too and test that, the forecast's bloody cold for the weekend but my mate keeps his place at around 18 deg C so it'll be interesting to see if it affects either gun...

 

Cheers.

 

Feckin' snow... I'll try again next weekend....