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PSG-1 Sniper - Pneumatic gun

Posted: Thu Oct 07, 2010 2:36 pm
by Jenecplu
Hi.

For my first time here, I would like to present my pneumatic gun. I'm french and a patator.frbb.net forum member. Sorry for my poor english ^^

PSG-1

Dimensions:

Total length: 120 cm
Barrel: Inner diameter = 8 mm (3 mm thickness) / Length = 80 cm
Chamber: Diameter = 30 mm / Length = 30 cm
Weigth: 4.5 kg

Caracteristics:

It's a classic pneumatic gun based on an industrial with a QEV triggered by a spray gun and with a riffled barrel. I wanted something simple and effective.

The main reserve consists of a scuba tank with a regulator (no need to pump :D). The gun is connected to the output of the medium-pressure regulator that provides between 9 and 10 bars.

Inner arrangement :

Image

The breech (perfectly water-proof) :

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Tool to rifled the barrel (be careful, the pic is very big):

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The shell pine in progress:

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Performances:

Given by GGDT

Tight shot range: approximately 140 m
Parabolic shote range: approximately 400 m

I have some difficulties to believe it :D.

I still rarely used, but the accuracy improved significantly as you go. I think the rifled barrels being lapped. I have a correct accuracy at 20 m distance at which shots of the video are done.

The 2 bullets are extracted from the wooden plank, we can see traces of the grooves of the barrel. The 3 other bullets have hurted the rock :D: .


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Pics

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Video

[youtube][/youtube]

link to the topic : http://patator.frbb.net/conseils-aides- ... -t3474.htm

Posted: Thu Oct 07, 2010 3:02 pm
by Pete Zaria
Awesome gun! Great build, looks like you really researched it and took your time.

Mind providing us some details on how you rifled the barrel? How did you achieve a steady rate of twist?

Peace,
Pete Zaria.

Posted: Thu Oct 07, 2010 3:24 pm
by Heimo
I have to congratulate you, good attention to detail and the quality of the workmanship is impressive.
nicely done

Posted: Thu Oct 07, 2010 3:25 pm
by Gaderelguitarist
Absolutely beautiful shell. I love when people hide their pipes in wood. So much more elegant. :D

You clearly built this from careful thinking.

Posted: Thu Oct 07, 2010 3:45 pm
by Jenecplu
Thank you for your positive comments.

I'll try to explain how I have rifled the barrel, but I'm not sure to explain that very well in english ^^

On the third pic, you can see a screw. I have machined it with a "dremel". Al-gx, a patator.frbb.net forum's member, have calculated for me the rate of twist by using the bullet's velocity estimated with GGDT. I have converted this to degree, so more or less 5°.

I have drawed this angle on a wood plank to make caliber. Then I have machined it step by step, checked with a "caliper" (not sure of the traduction) and trying it in a little part of a 8 mm copper tube.

Then, I have attached a 3 mm rope in the hole done to the extremity of the screw (visible on the pic) and passed the rope in the barrel. I have twisted the rope in the right direction for rotation and pulled on it. The angle of the blade and the torsion of the rope have done the rest :)

Posted: Thu Oct 07, 2010 3:55 pm
by Gun Freak
This is an awsome gun! Pretty accurate and not bad power wise. Looks great too. You french guys make the best airguns. Good job 5/5!
And your translation of caliper was right :) You have good English, better than some Americans on here :D

Posted: Thu Oct 07, 2010 7:08 pm
by twizi
very nice woodscrafting
maybe some high presure and it would be even more awsome

Posted: Thu Oct 07, 2010 7:58 pm
by lozz08
congratulations, you should be proud of it. It would be cool If you could make one with a magazine so you don't have to put a pellet into the breech every time.

Posted: Fri Oct 08, 2010 1:44 am
by Jenecplu
Thanks all :)

It's my first pneumatic gun, I didn't want to make something too much complex for the first time. The magazine will be for a futur pneumatic gun. I already have the breech, so think I could more or less easily adapt a magazine. But it will need big modification of the shell or probably make a new one.

For the pressure, I think to change the setting of the regulator. I need to find a old one to tinker it. I don't want to modify the regulator on the video, I need it to breath when I dive :D

By changing the setting, I think to have 15 bars, may be 20. In this case, I need to reinforce the piston in the qev and replace the spray gun by something stronger.

Posted: Fri Oct 08, 2010 1:50 am
by lozz08
Do a video of you firing it 300 ft deep and then breathing from the same tank
:idea: :wink:

Posted: Fri Oct 08, 2010 4:04 am
by Crna Legija
Jenecplu wrote: By changing the setting, I think to have 15 bars, may be 20. In this case, I need to reinforce the piston in the qev and replace the spray gun by something stronger.
you don't need to replace the piston, people have used them up to 40 bar

Posted: Fri Oct 08, 2010 5:23 am
by ThornsofTime
Really good work mate. Again, being a noob on these forums I don't have much room to talk, but i always applaud this level of craftsmanship and finish on a spudder.

As a matter of fact I find it interesting that my FIRST POST EVER was on a stock-making tutorial.... and BOOM.... heres another great example.

I love your idea of pre-routering two different pieces of wood to contain the mechanics... then laminating them together. freehand router work requires skill and patients, and on both accounts you sir, are a good craftsman.

one last tidbit -(personal opinion)- 8-12" silencer would fit this build well...

Posted: Fri Oct 08, 2010 5:44 am
by FighterAce
Great job! You're the first person I see that makes replicas exactly like me :D

Posted: Fri Oct 08, 2010 6:03 am
by Zeus
Gun Freak wrote: You have good English, better than some Americans on here :D
Why would Americans have a mastery of English, if you observe both English and American, they have only some similes. I learned Latin, and if you know English, Latin is a breeze.

Enough of my pedantics, That is a very nicely carved stock, and your QEV should handle 20 bar with no problems.

A very good first post.

Posted: Fri Oct 08, 2010 2:39 pm
by Davidvaini
everything looks amazing.. and then it is ruined by the crappy $10 walmart looking scope (regardless if it is a $10 scope or not, it looks like it)

my 2 cents.