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Posted: Sat Oct 27, 2012 9:43 pm
by Gippeto
Very nice. 8)

Bought myself a little something as well. :)

Converted to .25 cal about 15 minutes after it arrived. :wink:

I think I need a new red dot too. :lol:

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Posted: Sun Oct 28, 2012 1:00 am
by jackssmirkingrevenge
Labtecpower wrote:Not bad for a 160€ gun I think, shooting 10 mm groups at 10 meter now, if I was a better shooter it'd be hole in hole :)
Nice, bet there are machined mods on the horizon ;)
Gippeto wrote:Bought myself a little something as well.
mmmm... this one? http://www.airgunsofarizona.com/blog/20 ... lecto.html

Pretty!

Crying out for a nice suppressor ;) What slug weight and how fast in 0.25"?

Posted: Sun Oct 28, 2012 7:01 am
by Labtecpower
Nice, bet there are machined mods on the horizon :wink:
Yep, I want a handle like the one I made for Jake, and I certainly want to give the gas ram a try, spring twang sound cheapy hehe

First change on the gun has been made;

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Found this ring behind the seal between the barrel and piston chamber, has a 2mm hole in it, so it chokes the flow tremendously.. and if I find something I don't like it gets pulled out :D
Next to it is a JSB exact 4.52 for comparison :roll:

Posted: Sun Oct 28, 2012 7:18 am
by jackssmirkingrevenge
Careful, the black art that is mastery of the springer airgun implies that a bigger transfer port does not necessary mean more power.

Posted: Sun Oct 28, 2012 8:56 am
by Labtecpower
I can't see the logic behind this black art...
The groups have gotten smaller since I took out this ring, it seems to have less vibrations..

Maybe i'll just put it back in for more testing
:roll:

Posted: Sun Oct 28, 2012 10:08 am
by jrrdw
Experiment with port sizes. Make several copies with different size ports...mite be fun.

Posted: Sun Oct 28, 2012 10:53 am
by Gippeto
Transfer port size in a springer can have a major effect on compression heating...hot gases flow faster...yes? Too little compression will also have the piston slamming into the end of the cylinder...not so good.

Jack... No suppressors here...suppressor= prohibited device = jail time.

A trade off I'm willing to make for an easily available firearms license (PAL). :)

Alecto...yes. :)

After "tweaking" the pressure relief valve, JSB Kings (25.4grain) @ 450 fps...20.5's would likely be getting ~470fps or so, which is getting close to the legal limit here which separates an "air pistol" from a "pistol"...which requires a license I don't have (RPAL) and adds restrictions to storage/transport/usage that take most of the fun out of an air pistol.

Should be plenty of snap for spring time "whack a mole". :wink:

Posted: Sun Oct 28, 2012 12:24 pm
by jackssmirkingrevenge
Gippeto wrote:Transfer port size in a springer can have a major effect on compression heating...hot gases flow faster...yes? Too little compression will also have the piston slamming into the end of the cylinder...not so good.
That's the gist of it, not something I would play with that much.
Jack... No suppressors here...suppressor= prohibited device = jail time.
I know, just putting it as a hypothetical. I bet it's not too loud in any case though :)
After "tweaking" the pressure relief valve
I read that as "jamming in place" :D
JSB Kings (25.4grain) @ 450 fps...20.5's would likely be getting ~470fps or so, which is getting close to the legal limit here which separates an "air pistol" from a "pistol"...which requires a license I don't have (RPAL) and adds restrictions to storage/transport/usage that take most of the fun out of an air pistol.
Very decent for an air pistol, that's just under the legal limit for air rifles in the UK!

Reminds me of the Quackenbush efforts: http://www.quackenbushairguns.com/shot_pistol.html

Posted: Sun Oct 28, 2012 1:04 pm
by Labtecpower
That's the gist of it, not something I would play with that much.
popped it back in place, needs more research before I make any changes :roll:
I still think it's too small, a lot of other guns have a hole about a mm bigger..

Posted: Sun Oct 28, 2012 1:12 pm
by jackssmirkingrevenge
Labtecpower wrote:I still think it's too small, a lot of other guns have a hole about a mm bigger..
... but they have different piston diameters and strokes, spring strengths etc.

As jrrdw suggested:
Experiment with port sizes. Make several copies with different size ports...mite be fun.
Grab a chrony and do some science!

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Random footnote, wyz - come come you never mentioned this?

Posted: Sun Oct 28, 2012 1:33 pm
by Labtecpower
... but they have different piston diameters and strokes, spring strengths etc.

As jrrdw suggested:
True, I shouldn't apply the figures of other guns to mine :roll:
Grab a chrony and do some science!
I hope I can find someone near me who has one, I don't have the money to buy a chrony for testing purposes :D

Posted: Sun Oct 28, 2012 2:43 pm
by jackssmirkingrevenge
Labtecpower wrote:I hope I can find someone near me who has one, I don't have the money to buy a chrony for testing purposes :D
Could be something a bit more rudimentary since you're mainly interested in relative data as opposed to actual fps values. For example water filled beer cans in a row, count how many each variation penetrates.

Posted: Sun Oct 28, 2012 2:52 pm
by jrrdw
Labtecpower wrote:but they have different piston diameters and strokes, spring strengths etc.
Don't let that stop you, so much as .05mm might make a outstanding differance. You never know, if you have the means and time etc...

Posted: Sun Oct 28, 2012 2:57 pm
by Labtecpower
I'm going to take a look at work tomorrow, if i'm lucky they have very thin 14 mm rings somewhere :P

I have very little time on my hands, but that isn't enough to stop me from having fun hehe

1000!!

Posted: Sun Oct 28, 2012 3:07 pm
by jackssmirkingrevenge
Labtecpower wrote:I'm going to take a look at work tomorrow, if i'm lucky they have very thin 14 mm rings somewhere :P


... and plenty of empty beer cans :D
1000!!
pfffft...

:D :D :D