Strange Results from Angry Gun Power Up Suppressor

[aznpos531]

I recently bought and installed the Power Up Suppressor for my KWA Kriss Vector and I've been getting odd results. The FPS has increased by about 100 FPS (up to about 430 from about 330) and the accuracy is more or less unchanged (groupings with and without the suppressor are comparable). However with the suppressor attached the point of impact is lower than without; I'm having to aim higher than my intended target to hit it. Hop-up is turned all the up already and the iron sights can't be adjusted enough to correct it. Also the gun already has a 6.01mm TB inner barrel to match the one inside the suppressor. I've also checked to insure the continuity of the inner barrel of the gun with the one in the suppressor. Would like to hear your thoughts on this.

[ShelledPants]

What is the distance you are zero'ing at? A KWA with max hop should almost be overhopping every round up to .30's at 100 feet.

[targetGspot]

On my project build I acquired a used metal body with outer barrel that turned out to be slightly bent at threads. When I went to put on the silencer it became obvious that it was out of whack. I was able to heat and bend straight. Perhaps you have a similar issue causing the angry gun's inner barrel extension to aim ever so slightly downward, but not enough to jam up?

[audi_bhoy]

Well, your silencer's inner barrel needs to line in within .01mm with your gun's inner barrel otherwise it will change the direction of the BB since both aren't aligned to perfection. My guess is that your silencer is aiming slightly towards the ground.

IMO 2 pieces inner barrels doesn't add any accuracy at all, it mostly does the opposite.

[aznpos531]

Originally Posted by ShelledPants

What is the distance you are zero'ing at? A KWA with max hop should almost be overhopping every round up to .30's at 100 feet.

For the purpose of testing the barrel I had the gun zeroed at about 45 feet and it was fairly accurate being able to consistently hit a pop can at that distance. With the suppressor on I was able to consistently hit the pop can as well once I was able to compensate by aiming higher than the target.

Originally Posted by targetGspot

On my project build I acquired a used metal body with outer barrel that turned out to be slightly bent at threads. When I went to put on the silencer it became obvious that it was out of whack. I was able to heat and bend straight. Perhaps you have a similar issue causing the angry gun's inner barrel extension to aim ever so slightly downward, but not enough to jam up?

The outer barrel doesn't look bent to the naked eye. I'll examine further to see if this is the case.

Originally Posted by audi_bhoy

Well, your silencer's inner barrel needs to line in within .01mm with your gun's inner barrel otherwise it will change the direction of the BB since both aren't aligned to perfection. My guess is that your silencer is aiming slightly towards the ground.

IMO 2 pieces inner barrels doesn't add any accuracy at all, it mostly does the opposite.

I think this is the most probable explanation. Shining a light through the inner barrels, I can't see any misalignment but maybe it's just too subtle for me to see.

Thanks guys for your input. :cheers:

[Jimski]

misalignement is not the only thing: the threading probably reduces coaxiality between the two barrels, because there is less matter, so the silencer is probably pointing downwards.
You might be able to correct that, by stuffing stuff in the thread :/ ( teflon?)

wait, are barrels threaded into each other?

[ThunderCactus]

alternatively, the silencer could be pointed upwards, negating the spin put on the BB by the hop rubber.
I would say it's more likely it's bent down though.
Airsoft companies have never used any sort of international standard for threading, I wouldn't be surprised if you weren't at all able to achieve coaxial alignment. That's why I think these inner barrel silencers are such a stupid idea. There's also no mating between the two barrels to guarantee alignment.
If you're planning to ONLY run your vector with the longer barrel, you should think about getting a longer inner barrel instead of two sections of barrel.

Also, how is your fps so LOW? I'm averaging 1.4j on my vector using .30s, which is 400 on .20s

[aznpos531]

Originally Posted by Jimski

misalignement is not the only thing: the threading probably reduces coaxiality between the two barrels, because there is less matter, so the silencer is probably pointing downwards.
You might be able to correct that, by stuffing stuff in the thread :/ ( teflon?)

wait, are barrels threaded into each other?

No, only the outer barrel and the outer shell of the suppressor are threaded to each other. The inner barrels just meet edge to edge. I'll give the teflon a try and see how it turns out.

Originally Posted by ThunderCactus

alternatively, the silencer could be pointed upwards, negating the spin put on the BB by the hop rubber.
I would say it's more likely it's bent down though.
Airsoft companies have never used any sort of international standard for threading, I wouldn't be surprised if you weren't at all able to achieve coaxial alignment. That's why I think these inner barrel silencers are such a stupid idea. There's also no mating between the two barrels to guarantee alignment.
If you're planning to ONLY run your vector with the longer barrel, you should think about getting a longer inner barrel instead of two sections of barrel.

Also, how is your fps so LOW? I'm averaging 1.4j on my vector using .30s, which is 400 on .20s

I think pointing downwards is more likely. I'll fiddle around with it some more and see what I can do. The longer inner barrel was my initial plan but since this seemed easier I wanted to give it a try first. Wishful thinking I guess.

I've only had this gun for a few weeks so I wasn't sure what the FPS should be but it sounds like it's not up to snuff. Any ideas for possible explanations?

[ThunderCactus]

Well it's typically a matter of lubrication.
Anytime you get a new gas gun, put 4 drops of silicone in a mag and run it through, then take the gun apart, clean and re-grease all sliding surfaces.

With my WE PDW, I gained about .3j from lubricating it
With the vector, I vaguely recall it shooting 1.1-1.2j when I first got it, I just remember the increase after lubricating wasn't big. Retailers state you should be getting 380fps on .20s

Keep in mind that even though it has a short barrel, the muzzle energy will increase as you use heavier ammo.
Consequently, if you put a longer barrel in, it may increase the joule creep of using heavier ammo.
So if you have a .13j difference between .20 and .30 now, you may have a .2j difference with a longer barrel.

....actually someone should test that lol

[Styrak]

Originally Posted by aznpos531

The outer barrel doesn't look bent to the naked eye. I'll examine further to see if this is the case.

You wouldn't be able to tell. We're talking about millimeters, if that.

[Styrak]

Originally Posted by ThunderCactus

....actually someone should test that lol

Yes, longer barrels and heavier ammo both affect gas guns.

[ThunderCactus]

I mean joule creep on a long barrel versus joule creep on a short barrel, so see how much of a difference it makes

[Kos-Mos]

Originally Posted by ThunderCactus

I mean joule creep on a long barrel versus joule creep on a short barrel, so see how much of a difference it makes

I can do that next time I do maintenance on my SCAR...

Got a "short" barrel and "long" barrel from an M4A1. Both stock WE, so they should be comparable in quality and bore etc.

[mcguyver]

Remove the inner barrel from the silencer.

Go to a music store and buy the felt pads used for drum cylmbals.

Install into silencer can.

Enjoy reduced FPS and a quieter gun.

Problem solved.

[aznpos531]

Originally Posted by ThunderCactus

Well it's typically a matter of lubrication.
Anytime you get a new gas gun, put 4 drops of silicone in a mag and run it through, then take the gun apart, clean and re-grease all sliding surfaces.

With my WE PDW, I gained about .3j from lubricating it
With the vector, I vaguely recall it shooting 1.1-1.2j when I first got it, I just remember the increase after lubricating wasn't big. Retailers state you should be getting 380fps on .20s

Keep in mind that even though it has a short barrel, the muzzle energy will increase as you use heavier ammo.
Consequently, if you put a longer barrel in, it may increase the joule creep of using heavier ammo.
So if you have a .13j difference between .20 and .30 now, you may have a .2j difference with a longer barrel.

....actually someone should test that lol

I finally figured out the source of the low fps. I had cleaned and re-lubed the gun but there weren't any significant changes. I finally found that the hop up rubber had torn and was sticking into the inner barrel at a rude angle significantly slowing down the bb and possibly affecting the accuracy as well. I'll have to order a new hop up rubber. Any suggestions?