Airgun Technologies Vulcan 3 HP 25 sudden speed loss

Thanks for the input. The factory spring seems to be of high quality. Probably symmetrical too. I had it in and out so many times that I would be surprised if I hadn't put it in the other way around already. I'll check later. Not so much fun playing with an old school chrony on a sunny day.

I sure think it's usually (always) something you've touched and messed with

Now I'm thinking if the hammer is the wrong way around. It shouldn't be. It did slide out to some extent, or all of it but I thought it was like it should be. Sure it could have turned around.

It seemed to be asymmetrical in many ways, and the most obvious being thickness. I feel the back end is a good fit for the spring, and the barrel end SEEMS smaller. If there's some difference in length as well then that should do it. It doesn't mean much if the hammer locks up with the sear. I don't know if that happens regardless orientation.
To be continued...

The hammer only goes in one way. It seems impossible to put it in the wrong way without removing the stud.
So back to square one. I still have absolutely no idea what's going on. Maybe I have to get a regulator tester and change the barrel o-ring for starters.

weevil said:

Does “Couldn't pull the cocking lever all the way back.” translate to “pulled it so hard that I likely deformed the linkages?”

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Thanks but no. I should have written "I didn't want to pull the cocking lever past half point for it being so hars, making metallic scraping sound plus being about twice as hard compared to original spring set at giving the 130FPE so not worth it anyways ".

The cocking mechanism seems simple. The lever and linkage shouldn't have anything to do with the hammer once hammer is locked with the sear. There's a hatch on the side and everything is moving freely.

I doubt the metallic scraping sound did any damage. The AAO spring is very low quality, not rounded off or treated anyways. There are no markings on the hammer from it so wherever it made the sound from, I'm not worried. Probably the end of the spring/springs finding their place under pressure.

But thanks. I appreciate all the help and let me apologize to everyone for probably sounding rude. I'm a middle aged blue collar worker from Finland not at all accustomed speaking English.

I appreciate everyone's time.

Emu said:

I had some days ago a problem with my Vulcan 2 .25 Cal.

The air cilinder was loose and went a little bit out of place, then the hammer was not reaching the valve to open it correctly. I just tighten the two screws that keep the air cilinder in place and everything return to happiness.

I do not have my Vulcan 3 infront of me, but try to see in your if a similar problem can be the cause of your decrease in power.

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Thanks. I'll take a look. I did go there after the problem occurred. I changed the depinger which I never should have done in the first place but that's another story. I noticed the two locking screws were different and I also saw somewhere mentioned an order about tightening them which I have forgotten all about. I reasoned the sharp ended (the larger one?) works by centering the valve with a matching cone shaped hole and hence should be tightened first. After that the second one, smaller (?) should be tightened. A flat surface on both the screw and the block. But yeah, I will check that out this weekend.

I'm always reluctant fixing things that aren't broke so not removing barrel every other day. Now I 'm at a point I have no accuracy to speak of and the rifle is just trustworthy enough to pop pigeons 50 yards away. Barrel fouling would be another possibility and the o-ring as well. I'll pull the barrel out.

Thanks

mohidris017 said:

Did you find what the problem is ?

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Not yet no

First of all, there's nothing new.

I started by removing the barrel and inspecting the O-ring. It's fine.
Cleaned the barrel. Noticed right up that there would be no benefit in that. Not much came out, not even with lead remover.
I installed the o-ring back into the barrel with liquid silicone from Huma Air.
In the process of installing the barrel I noticed you can set it in too far, so that the magazine doesn't fit. That's awkward. Luckily I tried the magazine so no harm done, but would it have hurt AGT to fix that one? I decided to install the barrel all the way in with the magazine and back up just a little. To be clear, I do not condone such methods but lacking precise markings it had to do.

Took the plenum apart and changed the depinger back to original. I paid close attention to installing the valve into the block just like fellow member Emu suggested. The markings on the cone shaped hole gave Me hope. I could have believed it had moved. I installed it by applying some force from the bottle end and tightened the screws while doing so. I reasoned that if they were misaligned, they are not anymore.

Back at the farm I shot through chrony and was sorely disappointed. I had 280bar in the bottle. First shots around 920fps. Tightening the hammer spring gradually gave no more than 970fps. That was after some 6 revolutions of hammer adjustment . Somewhere around there it does not lock the hammer anymore.

If there is one thing I picked up from all this, it's the not so linear effect from the hammer adjustment. You get the 920 without breaking sweat, and to reach 970 you turn the hammer spring quite a lot. And yeah, air consumption is wild! Above 930 or something the sound changes radically. It's clear that the air just spits out in an uncontrolled manner. One would think that it correlates with too low reg pressure? I haven't touched that.

I'm thinking of tossing it into the sea but the damn thing probably floats.