Rifle Scopes Heat damage to a scope

senicpines

Private
Minuteman
Jun 25, 2009
1
0
62
I live in Phoenix and if I let my rifle sit in my car for any length of time the temperature can get up to and past 160 degrees (but it's a dry heat... haha). Anyway, I was looking at a zeiss diavari and the zeiss site showed an operating range up to only 122 degrees. So what does high heat do to a scope, are some more able to stand the heat? thanks
 

CoryT

Gunsite Rangemaster
Commercial Supporter
Full Member
Minuteman
  • Mar 5, 2004
    1,844
    890
    64
    Paulden, AZ
    www.gunsite.com
    Re: Heat damage to a scope

    What may happen is the cement used to secure the lenses and fittings softens up and components shift, not a good thing. What happens to the ammo is another problem altogether.
     

    HitEmHard

    Private
    Full Member
    Minuteman
    Jun 10, 2004
    172
    163
    San Antonio, TX
    Re: Heat damage to a scope

    Might also void the warranty, if they determine any damage was heat-related. Call them- everyone I ever talked to at Zeiss was well-informed.

    D
     

    psinclair

    Gunny Sergeant
    Commercial Supporter
    Full Member
    Minuteman
    Jul 11, 2008
    3,386
    461
    64
    Glasgow, Montana
    Re: Heat damage to a scope

    A friend of mine left a pair of Leica binoculars on the front seat of his pickup with the windows up on a 100F day and completely ruined them....not a good idea.
     

    sub2.908cm/100m

    Sergeant
    Full Member
    Minuteman
    Re: Heat damage to a scope

    No doubt in my mind it's an issue, but here in Florida lots of guys keep their duty rifles in the trunk day in day out for years. Most are pretty anal about covering the optics between relays on the line though
    wink.gif


    Never had an issue with our Leupolds in over 20 years BUT, did have a personal 18-36 Tasco spotting scope that had to be rebuilt, I suspect for that very reason, but that was after riding around in the trunk for about 15 years.

    Maybe it's just the humidity
    wink.gif
    smile.gif
    grin.gif
     

    SFree

    Sergeant
    Full Member
    Minuteman
    Jan 20, 2005
    815
    162
    USA
    Re: Heat damage to a scope

    Then how are guys in the sandbox protecting their optics when temps are 120-130 degrees?
     

    Mike in Seattle

    Private
    Minuteman
    Oct 20, 2004
    27
    0
    Auburn wa
    Re: Heat damage to a scope

    Hmmm,,


    I went to USO site, and couldn't find anything relating to min-max temps.



    Any of the USO guys tell us a bit about that ??
     

    Chucky

    Gunny Sergeant
    Full Member
    Minuteman
    Jul 19, 2006
    904
    57
    41
    Sanford, NC
    Re: Heat damage to a scope

    I had a Unertly on our .50 Barrett that the mil dot's melted. The gun shot good though so I got over it. We didn't do anything in country to our scopes other than use scope caps.

    Chuck
     

    pinzmann

    Sergeant
    Full Member
    Minuteman
    Oct 5, 2005
    534
    2
    yucca valley, ca
    Re: Heat damage to a scope

    I left my Leupold Mark 4 Bino's under the pass. seat of my Unimog. Only later did I realize the exhaust pipe was right under that. When I went to grab them they were too hot to touch and had scorched a bit of the rubber coating. Still works like a charm.
     

    stillbuster

    Sergeant
    Full Member
    Minuteman
    May 14, 2008
    314
    0
    Tupelo, MS
    Re: Heat damage to a scope

    Bought a set of Nikon Action Binos in 96. Since the date of purchase they have hanged on the passenger head rest of my cruiser day in day out heat and all, not a single problem with them.
    I have often wondered what actually happens to a "purged" optic when it sits in a 200 degree vehicle days on end.
     

    gyr

    Sergeant
    Full Member
    Minuteman
    Apr 4, 2006
    236
    0
    EU
    Re: Heat damage to a scope

    Someone do a heat torture test on a SB and a USO ¡¡
     

    rijndael

    Major Hide Member
    Full Member
    Minuteman
  • Jan 20, 2004
    1,081
    163
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gyr</div><div class="ubbcode-body">Someone do a heat torture test on a SB and a USO ¡¡</div></div>

    A few years ago, I got my suppressed .308 rifle so hot, I couldn't touch the bottom metal. The stock even felt hot to the touch - it was a McMillan A1 w/ Sniper Fill.

    I'm sure the USO scope got really hot since it had more metal to metal contact than the bottom metal ....

    It did just fine.
     

    Phil1

    Sergeant
    Full Member
    Minuteman
    Mar 3, 2009
    467
    5
    Minot N.D.
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gyr</div><div class="ubbcode-body">Someone do a heat torture test on a SB and a USO ¡¡

    </div></div>

    For what its worth according to Nightforce "Thermal stability is tested by freezing the scopes in a nitrogen atmosphere to -80 degrees fahrenheit and then heated to 250 degrees fahrenheit in a one hour period."
     

    Insayn

    Sergeant
    Full Member
    Minuteman
    Jan 7, 2008
    887
    9
    DFW, Texas
    Re: Heat damage to a scope

    I have a Leupold where the seal blew or softened and released the gas inside. The lenses are fogged on the inside and it looks like a liquid has run and dried on the lens. I haven't sent it back yet.
     

    doc76251

    Gunny Sergeant
    Full Member
    Minuteman
    Dec 5, 2003
    1,747
    41
    Virginia Beach, VA
    Re: Heat damage to a scope

    USO's reticles are etched and filled so there is nothing to melt. Other than that question there is nothing in a USO that can melt in any temp that the sun can make on this planet. IIRC the "glue" we use has a higher temp rating than the brass and aluminum. I don't recommend putting one in an oven but I wouldn't sweat it otherwise.

    Cheers,

    Doc
     

    mikieg

    Sergeant
    Full Member
    Minuteman
    Sep 23, 2008
    189
    0
    sapulpa oklahoma
    Re: Heat damage to a scope

    last week at the badlands advanced phase 1 course, i saw a new mark 4 give up the ghost. now remember, the temps were solid triple digits. their unknown distance range is 2200 acres without trees. we shot unknowns for 2.5 days! durring that time i saw a total of 3 failure to connects. two of these were mine. the last day we were shooting ukd's the targets were 13 inch disks at 725yds. the sweat was so bad my eyes were on fire. everything was on fire, the spotter was so hot you could not touch it! the mirage was sooo thick you could cut it with a chainsaw! still hit two of three targets.
    friday we did a land nav course, great fun in the heat. then we had our 100-600 yard qualification shoot. i knew durring the initial 100- 1000 yard dope drill, there was something wrong. my dope numbers were waaaay off. my rifle seemed to be shooting extreemly flat. and by the night fire course i knew i was in trouble. the qualifier was terrible. i had two rifles shooting 4-5 moa groups. it was so hot that after a couple shots, your rifle just stayed hot all day. i recorded mid barrel temps in the 160's!
    at that time i used my ammo in two other guns. more than acceptible performance. so now i am suspecting that both of my super snipers may have puked their guts out in the heat. after testing, i will get back to you all on that.
     

    Grump

    Gunny Sergeant
    Full Member
    Minuteman
    Oct 23, 2008
    1,221
    10
    61
    So. Utah
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">USO's reticles are etched and filled so there is nothing to melt.</div></div>
    The inquiry does NOT end there. WHAT are they filled with?

    AFIC, absolutely NO piece of kit is worth beans if it cannot withstand up to at least 160°F. You can hit than on even a sand-colored item left out in the sun anywhere from 1500 ASL in the Mojave to 4500 ASL in southeastern Idaho.

    I will never buy an Audi again, because not only the black plastic in the interior gets hopelessly brittle after only 8 summers, even what looked like white nylon in the shift assembly also started cracking and disintegrated after 9 summers--and those 3 parts were totally hidden from the sun under a leather shift boot and were consistently "cooled" to 130° by passing air during summer drive times. Plus, IT AIN'T SUMMER ALL YEAR LONG!!!

    If a scope can be cooked to a bit above boiling at sea level without ill effects, well, that's the way they ALL should be. Anything not rated for *use* above the surprisingly-common temp of 120°F should at least be able to stand mere exposure to at least 160 without falling apart or losing zero or melting its reticle. I've had plenty of LCD devices that worked just fine after getting too hot to touch--I just wiped down the screens with a wet cotton rag to cool them and could see they were still working, I just couldn't read the evidence.

    If your scope can't stand the type of heat that my Palm phone and my chronograph have held up to for years, then it's a piece of s**t and you should get every dollar back you paid after it pukes. Replacing it with another *piece* that can't take the heat is unacceptable.
     

    doc76251

    Gunny Sergeant
    Full Member
    Minuteman
    Dec 5, 2003
    1,747
    41
    Virginia Beach, VA
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Grump</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">USO's reticles are etched and filled so there is nothing to melt.</div></div>
    The inquiry does NOT end there. WHAT are they filled with?

    </div></div>

    Titanium bonded between two layers of Shott optically fine glass wrapped in 4130 chrome moly, 6061 - T6 aluminum, brass, tungsten, and stainless all made to look pretty with Type III hard anodizing and a fair sprinkle of JBWIII's special blend of pixi dust.

    Heat "could" break it down but not any heat that YOU will survive.

    Cheers,

    Doc
     

    Grump

    Gunny Sergeant
    Full Member
    Minuteman
    Oct 23, 2008
    1,221
    10
    61
    So. Utah
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Titanium bonded between two layers of Shott optically fine glass
    [snip]
    Heat "could" break it down but not any heat that YOU will survive.</div></div>
    NOW you're talking!

    I *suppose* that the IR/thermal pulse from a Nuke could melt that titanium without heat-cracking the glass...but the arrival of the shock wave shortly thereafter would make all of that a very, very moot point.
     

    Mike in Seattle

    Private
    Minuteman
    Oct 20, 2004
    27
    0
    Auburn wa
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> ,,, and a fair sprinkle of JBWIII's special blend of pixi dust </div></div>

    cool.gif
    OK,,, I'm good !

    , not gonna worry about the November rain & mud either.




    Thanks, Doc !!
     

    palma

    Full Member
    Full Member
    Minuteman
    Jun 7, 2005
    14
    0
    Hoover, AL
    Re: Heat damage to a scope

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Grump</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">USO's reticles are etched and filled so there is nothing to melt.</div></div>
    The inquiry does NOT end there. WHAT are they filled with?

    </div></div>

    Titanium bonded between two layers of Shott optically fine glass wrapped in 4130 chrome moly, 6061 - T6 aluminum, brass, tungsten, and stainless all made to look pretty with Type III hard anodizing and a fair sprinkle of JBWIII's special blend of pixi dust.

    Heat "could" break it down but not any heat that YOU will survive.

    Cheers,

    Doc </div></div>

    In my experience, USOs are the worst for failing under hot conditions. The glue that USO uses to hold the reticle in place appears to be one step above Elmers. I've seen several let go myself, and hear of bunches more. Never seen a NF or even a Leupold let go.
     

    300WSM

    Gunny Sergeant
    Full Member
    Minuteman
    Apr 29, 2004
    1,395
    5
    WI
    Re: Heat damage to a scope

    lol

    palma your always bashin John and USO. I've never had a problem with my scope in heat or cold. Even in -25 it worked for me! Heat...sitting in the sun for hours I would imagine it got above 120. Yet no problems.

    Why don't you send the scope into USO and have them fix it and then sell it. Beats the hell outta sending it to germany!
     

    Buldog

    Sergeant
    Full Member
    Minuteman
    Re: Heat damage to a scope

    After some research I came to the following conclusion rather quickly.

    <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> In my experience, USOs are the worst for failing under hot conditions. The glue that USO uses to hold the reticle in place appears to be one step above Elmers. I've seen several let go myself, and hear of bunches more. Never seen a NF or even a Leupold let go.</div></div>

    Palma, you do not know what you are talking about.


    Look it up for yourself.

    http://www.elmers.com/msds/me375_c.htm

    --- VS. ---

    http://www.norlandprod.com/adhesives/NOA%2061.html