Page 1 of 2

Finished .177 air rifle

Posted: Sun Sep 18, 2011 8:35 am
by jmez1996
After slaving away over the weekend i managed to finally finish my multishot .177 cal air rifle.

SPECS:

Tank: 29.5mm OD, 15MM ID X 480mm long. HQ stainless tubing. pumped to 260psi

Barrel: 4.5mm ID x 600mm long. (.177 cal) steel tubing

Valve: 1/4 QEV for like $12 free postage off ebay. (modified to allow barrel filling thanks to a post i saw by JSR)

pilot: 1/4" blowgun valve.


It pumps to 260psi (limited to this due to only a bike pump) through the quick connect in the bottom. and gets 4-6 strong shots per filling. I shoot .177cal air rifle pellets. THere is a 1/2" ball valve between the tank and firing chamber allowing the air to be divide, but after filling i open it slightly to allow semi-auto (still have to reload with bolt-action breech)
I am very impressed with the results and it is SOOO much better than my old gun.

thanks again to everyone here at spudfiles for answering my questions about valves and general pneumatics. special thanks to JSR for helping with the mod to the QEV allowing chamber filling :D although i didnt ask you directly.
ill be happy to upload component photos if people want them :)

cheers.

Posted: Sun Sep 18, 2011 8:56 am
by Brian the brain
Beautiful!
Even better than the first!

Can you give us a vid of it in action??

Posted: Sun Sep 18, 2011 9:11 am
by wyz2285
looks good, if you can get it to higher pressure, you will get more shot per fill with better power, 260 psi is a little low for lead pellets in my opinion. Good job!

Posted: Sun Sep 18, 2011 9:21 am
by nathanhd123
Nice job. Much better than first and like Brian said, can we have a video of it.

Posted: Sun Sep 18, 2011 9:38 am
by CooperJS
Thats such a nice gun and i also second that on the video :D
what type of wood do you use and is that a proper air rifle barrel?

Posted: Sun Sep 18, 2011 9:55 am
by jackssmirkingrevenge
Yes, videos please! Very nicely put together, kudos!

Posted: Tue Sep 20, 2011 3:59 am
by far_cry
what about accuracy ?

good job man, and start search for more pressure

Posted: Tue Sep 20, 2011 5:46 am
by jmez1996
far_cry wrote:what about accuracy ?
Yeah accuracy was one of my main points of interest when making this gun, and i mounted the gun today in a vice and shot some groups of 5 shots (1 filling of the tank) and got groups of around 7 cm. I am reasonably happy with this, and im assuming the inaccuracy is a result of the change in pressure of the shots. However the first and last shot (emptying the tank) were very accurate and hit about 0.5cm apart.

Posted: Tue Sep 20, 2011 5:49 am
by jmez1996
thanks for the comments everyone!
ill try get a video up in the next few days.

Posted: Tue Sep 20, 2011 5:52 am
by jackssmirkingrevenge
jmez1996 wrote:im assuming the inaccuracy is a result of the change in pressure of the shots.
If they were in a vertcal line, then yes. If they were spread randomly in a 7cm dia circle, then it's something else.

What distance were you shooting at?

Why not fit optical sights, some good mounting advice in this thread.

Posted: Tue Sep 20, 2011 6:00 am
by jmez1996
yehh they were in a generally vertical line which was what led me to believe this.
oh sorry forgot to say, 10m measured to the cm ;)

i'd also think its because the barrel isnt rifled.

Posted: Tue Sep 20, 2011 6:12 am
by jazzman56
Nice rifle, any chance of those component pictures, you have inspired me to build my own version (if i can source the parts).

Looking forward to the video.


What's that tingling

another case of spud fever :)

Posted: Tue Sep 20, 2011 6:21 am
by jackssmirkingrevenge
jmez1996 wrote:i'd also think its because the barrel isnt rifled.
Medium weight airgun pellets generally fly pretty straight even from a smoothbore barrel due to their shape and weight distribution. The critical portion is the muzzle, because this is the last contact which the projectile has with the barrel.

A good DIY guide to adding a crown to your barrel: http://www272.pair.com/stevewag/muzzle/mz.html

Posted: Tue Sep 20, 2011 6:21 am
by inonickname
jmez1996 wrote:
far_cry wrote:what about accuracy ?
Yeah accuracy was one of my main points of interest when making this gun, and i mounted the gun today in a vice and shot some groups of 5 shots (1 filling of the tank) and got groups of around 7 cm. I am reasonably happy with this, and im assuming the inaccuracy is a result of the change in pressure of the shots. However the first and last shot (emptying the tank) were very accurate and hit about 0.5cm apart.
Sorry but that's not great accuracy from a vice at 10 meters. It's a result of the smoothbore barrel and projectile.

Posted: Tue Sep 20, 2011 6:27 am
by jmez1996
inonickname wrote:
jmez1996 wrote:
far_cry wrote:what about accuracy ?
Sorry but that's not great accuracy from a vice at 10 meters. It's a result of the smoothbore barrel and projectile.
yeah i know its not great but i can hit a softdrink can at 14m with my first shot with no form of sights so im happy enough :)