Temperature and poi

[Hateful McNasty]

So early this morning it felt a tad cooler at 79°+/-. So my shots were running high . Just left things up and came back and shot and pretty much on at 95° +/- . Looking like a 3" difference..

The gun (R9.177) was outside air ambient . Anyway figured that made a pretty good change in poi due to temperature .

R9, irons, 75y ,cphp.177 79° shots and 95° shots

 

[PasadenaMike]

Can’t believe nobody has chimed in. I feel like poi shifts are absolutely normal in different temps in springers because the parts expand and contract in different temps causing the piston to work differently in different temps. Agreed ? I think it kinda makes sense. It’ll be minute of squirrel but maybe not minute of squirrel eye.

 

[Hateful McNasty]

Can’t believe nobody has chimed in. I feel like poi shifts are absolutely normal in different temps in springers because the parts expand and contract in different temps causing the piston to work differently in different temps. Agreed ? I think it kinda makes sense. It’ll be minute of squirrel but maybe not minute of squirrel eye.

On irons it not much if any but scoped it is a factor. Irons are more trustworthy then scope off the rack ..

Still it's a fact in life hot expands and cold contracts. Movement is movement.

 

[PasadenaMike]

On irons it not much if any but scoped it is a factor. Irons are more trustworthy then scope off the rack ..

Still it's a fact in life hot expands and cold contracts. Movement is movement.

Yeah add a scope to the equation with a billion moving parts temp makes a difference. In HFT guys cover their scopes and some even carry a temp gauge. Me, I just shoot lol

 

[Danman]

Oh this is interesting!! I had sighted in my new TX200 as soon as I got it (obviously !?) Out of the box with medium mounts and hawke airmax it's first 4 shots @25yards were dead on Left/right but 4 inches low. After some clicking and shooting it was centered. This was early December and weather was probably plus 10C. Took 40 or so shots to verify all was good. Then I pulled it out weeks later zero degree weather, same distance, and it was shooting quite low again. I was curious if it was temperature, scope, me lol, it was still a new gun, etc? Cold air is more dense so pellet would have to push a little harder.... Your shots being high in cold is confusing to me!? Ps....not an expert on this!

 

[PasadenaMike]

Oh this is interesting!! I had sighted in my new TX00 as soon as I got it (obviously !?) Out of the box with medium mounts and hawke airmax it's first 4 shots @25yards were dead on Left/right but 4 inches low. After some clicking and shooting it was centered. This was early December and weather was probably plus 10C. Took 40 or so shots to verify all was good. Then I pulled it out weeks later zero degree weather, same distance, and it was shooting quite low again. I was curious if it was temperature, scope, me lol, it was still a new gun, etc? Cold air is more dense so pellet would have to push a little harder.... Your shots being high in cold is confusing to me!? Ps....not an expert on this!

Makes a lot of sense

 

[Hateful McNasty]

Gas tams can heat and cool and affects the pressure in the ram .. I zeroed at like 70+° then went on a early morning hunt like 45° and just missed everything .
By the time I got back and all I'd check the gun late in the afternoon bit the temp was back up around 70 . Well it was pretty darn on . So ended up getting out early and cold again. And shot and was low / off zero cronie showed slow ..
So as the day warmed up I'd go shoot and the poi was heading back to zero .
So when the temp got to where I zero d at it was back spot on and cronied back fast/ normal for the pellets used ..

Next day repeated and same results.

Ya, I fell for the has ram better then spring hype.. I'll take spring anyday .

Then about leaving a spring cocked is malarkey.. how many times I maintain my springer and forgot to decock it and came back next day or when ever to recover that .. gun still shot great ...lol

 

[PasadenaMike]

Gas tams can heat and cool and affects the pressure in the ram .. I zeroed at like 70+° then went on a early morning hunt like 45° and just missed everything .
By the time I got back and all I'd check the gun late in the afternoon bit the temp was back up around 70 . Well it was pretty darn on . So ended up getting out early and cold again. And shot and was low / off zero cronie showed slow ..
So as the day warmed up I'd go shoot and the poi was heading back to zero .
So when the temp got to where I zero d at it was back spot on and cronied back fast/ normal for the pellets used ..

Next day repeated and same results.

Ya, I fell for the has ram better then spring hype.. I'll take spring anyday .

Then about leaving a spring cocked is malarkey.. how many times I maintain my springer and forgot to decock it and came back next day or when ever to recover that .. gun still shot great ...lol

Even PCPs . Anytime I’m about to hunt I check and adjust zero because my comfortable 77 degree shooting range isn’t the same as 34 degrees in the desert where i go in the morning to hunt

 

[Danman]

Yeah the TX was cronied on its last outing. It was doing 840fps with the 8.44jsbs. When I bought it in December it was shooting em @ 880fps-ish. I cleaned barrel out again (it was pretty leaded) and thought maybe that was it? Will try again next week.... Weather seems to be looking decent!

 

[Hateful McNasty]

I set a card with a 3"+/- cross on it at 10m or 50foot if I think I need a preshoot to check windage and all. Most times after a good barrel cleaning . Mostly for me it's windage poi . Usually just a couple of clicks ( true air gun sight clicks are 1/10 mm @ 10m / 4 clicks on a target ring to ring ).

Just found I had this ..not the cross bit a poi check card

For that above was top/bottom mildot and cross hair ... So I guess no canting

 

[Hateful McNasty]

So using reclaimed shot pellets from a trap I did a 3 day poi check at 50foot on irons ,
Reclaims


Fri , sat and Sunday. Off the gun rack cold

Bench look


And the usual 12+ mph wind . ( A bit cooler today as well)


Just tough to tell if it's the gun , pellets or weather cause it's never me

 

[Dogowski]

So early this morning it felt a tad cooler at 79°+/-. So my shots were running high . Just left things up and came back and shot and pretty much on at 95° +/- . Looking like a 3" difference..

The gun (R9.177) was outside air ambient . Anyway figured that made a pretty good change in poi due to temperature .

R9, irons, 75y ,cphp.177 79° shots and 95° shots
View attachment 1533

Do you live in Texas or Arizona where it hotter right now? That's some high temps where your at brother.

 

[Hateful McNasty]

Do you live in Texas or Arizona where it hotter right now? That's some high temps where your at brother.

Free state of Florida /USA.. heck it's has been 73-80° this cooler day was from yesterday's front of storms and going to be back mid 70's+ like maybe starting the warm up tomorrow..lol

 

[Dogowski]

Free state of Florida /USA.. heck it's has been 73-80° this cooler day was from yesterday's front of storms and going to be back mid 70's+ like maybe starting the warm up tomorrow..lol

I forgot about Florida! I was there last in 2008 in June when my kids were teens and it was 105 degrees and we went to the theme parks. I thought I was literally going to die from heat stroke. Man the humidity is just killer!

 

[Hateful McNasty]

I forgot about Florida! I was there last in 2008 in June when my kids were teens and it was 105 degrees and we went to the theme parks. I thought I was literally going to die from heat stroke. Man the humidity is just killer!

Ya, that 95+° and 95% humidity is hard on a guy.. makes ya praise the AC gods ..

 

[Hateful McNasty]

So using reclaimed shot pellets from a trap I did a 3 day poi check at 50foot on irons ,
Reclaims
View attachment 5118

Fri , sat and Sunday. Off the gun rack cold
View attachment 5119
Bench look
View attachment 5120

And the usual 12+ mph wind . ( A bit cooler today as well)
View attachment 5121

Just tough to tell if it's the gun , pellets or weather cause it's never me

Figured waiting on the grill I'd do a quick Monday poi check

I'd say on this it's inconclusive . My eyes, Wind, my hold, pellet, sun light / direction, ECT

Honestly can't complain and I've seen far worse . I'll call it pretty stable on the R9/hw95.

The same 50 foot.. one pellet was fresh new and one was a preshot reclaimed ..


Then just popped one in at 50 yards for fun .. ( fresh new pellet)


Seems my biggest offender is the Gamo with that gas ram .. temperature ° swings = poi swings .

 

[Hateful McNasty]

Figured waiting on the grill I'd do a quick Monday poi check

I'd say on this it's inconclusive . My eyes, Wind, my hold, pellet, sun light / direction, ECT

Honestly can't complain and I've seen far worse . I'll call it pretty stable on the R9/hw95.

The same 50 foot.. one pellet was fresh new and one was a preshot reclaimed ..
View attachment 5129

Then just popped one in at 50 yards for fun .. ( fresh new pellet)
View attachment 5130

Seems my biggest offender is the Gamo with that gas ram .. temperature ° swings = poi swings .

Ol'R9 tries to hold straight this morning cold 50yard , pretty nice morning at 52° climbing.

First shot from left off yesterday 50y above


2 more check my work shots


My pro set up

 

[PasadenaMike]

Notos is all over the place. I just cleaned the barrel. I made sure the barrel is tight. Next, I’m going to run a chronograph test lastly, I will shoot it again if she is all over the place again I’ll try different pellets. Maybe the premieres were a bad batch. If I can’t figure it out, I’m not gonna waste much more time with it. I’m just gonna sell it as is with full disclosure as a tinkerers wet dream lol.

 

[FL22]

Notos is all over the place. I just cleaned the barrel. I made sure the barrel is tight. Next, I’m going to run a chronograph test lastly, I will shoot it again if she is all over the place again I’ll try different pellets. Maybe the premieres were a bad batch. If I can’t figure it out, I’m not gonna waste much more time with it. I’m just gonna sell it as is with full disclosure as a tinkerers wet dream lol.

@Farmplinker2 be on the lookout

 

[PasadenaMike]

@Farmplinker2 be on the lookout

lol well I think I figured it out . I was running it below reg yesterday at the range. I had a chance to try it now in my new indoor range. (Just got upgraded to a Mercedes sprinter for work vs my old Metris) I have a 3 yard mobile indoor range