TM Desert Eagle shooting all gas at once

[TimeDeatH]

When I go to fire my desert eagle (propane with propane adapter) it fires about 4 shots, each firing a considerable amount of gas, then it stops, and you can hear the gas flow from the magazine until it fully runs out.

I believe the source of the problem lies either in the hammer inside the gun that touches the output valve, or the output valve itself (not likely).

I can get pictures and/or video if necessary.

[Ghast]

I agree with the hammer diagnosis. Something is preventing the hammer from going back, or causing it to be stuck forwards. Most problems on a GBB can be fixed by reassembling them, on the way you might notice something wrong or broken. So give that a shot.

[TimeDeatH]

Before taking it apart, I want to note (with the slide off) that when I pull the visible hammer (the one you pull back with your thumb) it pulls the silver hammer (the one that strikes the output valve) back only a little bit, but I can push it with my thumb and it goes back a lot more. This also happens when I rack the slide when the slide is on. Is the slide supposed to catch the silver hammer, or is the visible hammer supposed to do all the work? And is it only supposed to go back just a little bit, or all the way?

Edit: My guess now is that the silver hammer is too far forward after it fires a shot, causing the gas to release more and causing the gas flow when it stops. I can't really move anything farther back, and I can't screw the output valve in anymore, so what now?

[Knief]

Are you firing it indoors or outdoors? Most GBBs won't fire in cold temperatures, and will exhibit the exact behavior you're describing. If you're shooting it indoors, then proceed as planned.

[TimeDeatH]

Outdoors, I didn't realize the behavior would be that dramatic. I might have to wait a while to see if this is the problem.

[Knief]

That's the problem. Most gas guns won't function properly if it's colder than about 55 degrees outside (the exact temperature depends on the gun and the gas), and won't work at all when you start getting into the mid 40's and below. Take the gun inside, warm it up and shoot it into a pile of blankets or laundry or something (with eye protection on, of course). It should be back to normal. Just make sure you give the mag a couple of minutes to warm up after you fill it with gas. You want to make sure that it's at least at room temperature, though if you keep your place anything like mine in the winter, a little warmer wouldn't hurt. Tuck it into your pocket. If it shoots fine after that, you'll know it was just the cold.

[Thor]

You don't have to load it with BB's to test if it will cycle. Just hold down the magazine catch and keep pulling the trigger until it runs out of gas. Might stink up the place for a little bit, but other than that, no harm done.

[Knief]

Jan 4, 2011 19:32:02 GMT -5 Thor said:

You don't have to load it with BB's to test if it will cycle. Just hold down the magazine catch and keep pulling the trigger until it runs out of gas. Might stink up the place for a little bit, but other than that, no harm done.

True, but if the jam happens to relate to the bbs or how the mag feeds, you might not catch it and think you have a working gun until next summer. While that's probably not the case, and you'd probably be fine testing it with no bbs, I tend to like to test my guns in the condition in which I'll be using them. Just makes sure they're working the way they need to be. I guess it's sort of like the difference between test firing an M4 AEG with the upper receiver off. Sometimes they'll be fine with the upper off, but won't with the upper in place.

[BoredKender]

It could also be that the o-rings on your plunger valve are old and either swollen or cracked, causing the plunger to stick in place. If you can, try to find someone else with a mag you can test with before you go tearing your pistol apart.

[TimeDeatH]

Well, I just filled the magazine, stuck it in my pocket for 10 minutes, then fired it into an old pillow, where it fired 3 shots then the rest of the gas flowed out of the magazine. Also, the o-rings on the valve are just fine, because I recently had them soaking in pure silicone to fix a magazine leak (the gun was doing the same before this). The output valve moves pretty freely as well..

[BoredKender]

Just because they are soaked doesn't mean that they aren't worn. Just humor me and try the 10 cent fix before you go filing on your hammer

[Knief]

There's a good chance you froze and cracked your O-ring using it in the cold. When a gas mag vents it's gas, that gas comes out at a ridiculously cold temperature (it has to do with the physics of the pressure on the gas and the state change from liquid to gas). When most of a mag is purged, and especially if it's done a few times, as you've done, that cold temperature can freeze the rubber in the O-ring or gas route packing (the larger rubber piece on top of the mag), and it'll crack. This is why you should never manually purge your mags, and try to avoid venting them in a gun.

[TimeDeatH]

Jan 4, 2011 22:11:53 GMT -5 BoredKender said:

Just because they are soaked doesn't mean that they aren't worn. Just humor me and try the 10 cent fix before you go filing on your hammer

Will do. Is there any specific way for sizing them up so I can buy some online?
Edit: Just to note, I've had this problem before the gas leak in my magazine. O-rings aren't cracked, they look perfectly fine to me, but I guess it still doesn't hurt to replace them.

[Koko]

Jan 4, 2011 22:17:01 GMT -5 TimeDeatH said:

Jan 4, 2011 22:11:53 GMT -5 BoredKender said:

Just because they are soaked doesn't mean that they aren't worn. Just humor me and try the 10 cent fix before you go filing on your hammer

Will do. Is there any specific way for sizing them up so I can buy some online?
Edit: Just to note, I've had this problem before the gas leak in my magazine. O-rings aren't cracked, they look perfectly fine to me, but I guess it still doesn't hurt to replace them.

If you're solely using propane it could be very advantageous for you to use some silicon grease on your gun and some of it's moving parts as well. I know back when I had a GBB (*tear*) I would lube it and clean it after every two or three games MAX just to make sure everything was still moving how it should be because propane doesn't have that added benefit of silicon grease in it like green gas does.

[TimeDeatH]

Jan 8, 2011 18:00:40 GMT -5 Koko said:

Jan 4, 2011 22:17:01 GMT -5 TimeDeatH said:

Will do. Is there any specific way for sizing them up so I can buy some online?
Edit: Just to note, I've had this problem before the gas leak in my magazine. O-rings aren't cracked, they look perfectly fine to me, but I guess it still doesn't hurt to replace them.

If you're solely using propane it could be very advantageous for you to use some silicon grease on your gun and some of it's moving parts as well. I know back when I had a GBB (*tear*) I would lube it and clean it after every two or three games MAX just to make sure everything was still moving how it should be because propane doesn't have that added benefit of silicon grease in it like green gas does.

I always lube the gun, and the propane adapter (XG02) with silicone oil before using.

edit: I still have no idea how to figure out the size of these o-rings. I've taken them into hardware stores, but they didn't have them in small enough size. I'm also really doubting it's the o-rings, I don't even think I've put 200 rounds through this gun; not even 100 after the guarder metal body installment.