High velocity BB rifle

[Infernal Maveric]

This is a modification of my "QB" BB gun.
Chamber has been reduced significantly, as well as the pilot volume. To do the latter some bodging had to be done, but it holds pressure perfectly, and does the job I want it to.

Specs:
Barrel: 6.4mm Audi fuel line
Chamber: 15mm copper pipe
Ammo: 5.8mm BBs (0.12grams)
Valve: Detrol 1/2" QEV
Fill valve: Scharder
Pressure used: 300-400PSI

Enough with the numbers, onto the pictures.

Main gun.


The rear of the gun.


Comments/suggestions welcome.

[potatoflinger]

That looks pretty nice, but what is that thing under the barrel in the first picture?

[NoXi]

looks like a laser to me

[hi]

i think that a QEV such as that one is only rated at 150 psi. thats what mine is rated to anyway. maybe its rated at 150 because they know that people like you take it to 300.

it looks good, but why do you have such a small chamber. do you get better proformance than with a big chamber at lower pressure?

[Infernal Maveric]

Potato: Yeah that's a laser and a LED under the barrel. I use it to give a rough guestimate as to where the BB will fly at long(er) ranges.

Hi: The QEV is rated to 150PSI, but it's aluminium so I guess 400PSI is safe for that, but I'm not too comfortable taking it to 400 regularly, so 300-375PSI is what I shoot with.

As for the reason for the small chamber, is because my bike pump died on me, and I'm too broke to buy a new one. Performance wise I feel that the smaller chamber at 375PSI is way more powerful than my old chamber was at 120PSI or 200PSI (Max i charged it to with old chamber).

[windshrike]

Beeea-utiful.
Now add a stock.
That would significantly increase the aesthetic effect.

[f.c]

i wish i was able to create a gun like this. sadly my wallet is to light.

[Mitchza89]

Thanks a really nice gun. Looks like BB guns are on the list of guns to make at the moment .

[spud yeti]

Great looking gun. As someone above said, a stock would increase its aesthetics dramatically and really be awesome. What kind of speeds are you obtaining from it?

[Infernal Maveric]

I have no idea about the speeds, as I don't have access to a chrony, and am too poor to even consider buying one. But there is a loud crack when the gun is fired and makes my ears ring sometimes.

I might add a stock, but it would be difficult to add due to the compacted rear section. But I guess I can give it a go.

[jackssmirkingrevenge]

Barrel: 6.4mm Audi fuel line

Well posh aren't we

Very nicely done, it's good to see people acknowledging that for small calibres, low volume high pressure is better than high volume low pressure.

Yeah that's a laser and a LED under the barrel

ripped off a cheap airsoft pistol no doubt

[Infernal Maveric]

Jack: Posh as in using a mitre saw to hack it off from the carcase of a car that was saw at the scrap yard then yeah!

I figured that I can get more power from this set up than with my old set-up, and the only working pump I have now is a shock-pump or an air compressor, so the SP won hands down.

My little brother's BB-gun first had the later-dot on it...Until I stole it!