2240 overexpanding in sun



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Offline captwoody

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2240 overexpanding in sun
« on: February 18, 2011, 05:50:08 PM »
Twice now I have set my modded 2240 down in direct so cal sun 75 degee days. and after 20 minutes it blows the seal. the gun was not cocked either time. I am new to this so am i doing somthing wrong or do i have an install problem to my mods.( 2240 boss valve ) love how it shoots before blow out after it becomes under powered. take everything apart reseat it and it worked until 2nd blowout. what am i doing wrong?
  • murrieta,ca
2240BNM hi pac custom,2560BNMpcp custom ,winchester 1000 177 springer,800 winchester 177 springer,discoBNM 177,Marauder 22,p-rod,1740BNM custom hipac,25marauder carbine
crows-18, Ground squirrels-100+ lost track, Rabbits-35 (dont eat my grass)

Offline captwoody

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Re: 2240 overexpanding in sun
« Reply #1 on: February 23, 2011, 04:26:46 PM »
well sixty views and no input must mean this is unusual , so I will try one of mountain airs delrin valves and his spring kits let you know how it works out -woody
  • murrieta,ca
2240BNM hi pac custom,2560BNMpcp custom ,winchester 1000 177 springer,800 winchester 177 springer,discoBNM 177,Marauder 22,p-rod,1740BNM custom hipac,25marauder carbine
crows-18, Ground squirrels-100+ lost track, Rabbits-35 (dont eat my grass)

Offline Remo

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Re: 2240 overexpanding in sun
« Reply #2 on: February 25, 2011, 09:09:55 AM »
Hi Cap,

I think you answered your own question when you said that you put the gun down in  the sun.  Notwithstanding the ambient 75 degree temperature, direct sunlight can really heat up a 2240 pretty quickly.  Once she gets overheated, there's a good chance that the seal for the CO2 cart will get damaged/deformed and the gun will exhaust its charge.  If the seal is permanently damaged the gun will then fail to hold gas going forward.  At least this has been my experience from leaving a 2240 in the sun while indoors!!

Eric
AA S410 .177
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Crosman NPSS .177
Beeman R-7 .177
Beeman C-1 .177
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Offline jonnnyboy

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Re: 2240 overexpanding in sun
« Reply #3 on: February 25, 2011, 10:31:22 AM »
Capt, from reading and research I've found that co2 in direct sunlight can have much greater pressures than the normal 850psi.  I have heard from different sources that 1250 and maybe even higher psi is possible in direct sunlight and other hot environments.  One other issue might be the tightness with which you are sealing turning the tube's cap.  The manufacturer only recommends finger tight while many gun owners may be overtightening.  I have seen 2240s with plier marks on the tube cap indicating they had been tightened beyond what can be achieved by hand.  This would serve to compress the seal beyond its intended function and maybe cause a leak.

These would be my two guesses.  I hope you get it worked out.  I love mine and they are really great shooters.

joe
"Welcome to Tennessee, the patron state of shootin' stuff!"  ex-Marine Gunnery Sgt. Bob Lee Swagger

"A strong body makes the mind strong. As to the species of exercises, I advise the gun. While this gives moderate exercise to the body, it gives boldness, enterprise and independence to the mind. Games played with the ball and others of that nature, are too violent for the body and stamp no character on the mind. Let your gun therefore be your constant companion of your walks."  Thomas Jefferson

Offline captwoody

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Re: 2240 overexpanding in sun
« Reply #4 on: February 25, 2011, 03:17:09 PM »
Thanks fellas sounds like i have done 2 things wrong, leaving gun in sun and overtightning the cap . I have a new seal coming with a hipac 2240 bulk fill system, I think I will still add the delrin seal. once all parts are in I will post. hipac should be here any day now. later woody
  • murrieta,ca
2240BNM hi pac custom,2560BNMpcp custom ,winchester 1000 177 springer,800 winchester 177 springer,discoBNM 177,Marauder 22,p-rod,1740BNM custom hipac,25marauder carbine
crows-18, Ground squirrels-100+ lost track, Rabbits-35 (dont eat my grass)

Offline daveshoot

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Re: 2240 overexpanding in sun
« Reply #5 on: February 25, 2011, 03:42:23 PM »
Actually I have noticed pressure changes with plain old air in my Marauder Pistol. It was out for several hours in the patio area with temps in the 30s, and appeared to drop 100 psi or so. Bringing it back inside caused it to rise as it warmed up.

I would not be keen on filling it to the max and then leaving it in the hot sun, that's for sure. Being sort of a wimp about explosions I never fill any PCP quite to rated capacity, since the sweet spot in the factory settings is usually under max, anyway.

I run the rifle at about 2900 and the pistol at 2600. I am sure they have a heck of a safety factor built in, but no sense in tempting fate for very little payback.
Owner/operator of several air guns.

GTA - What's been your success with air gun target practice?