Page 45 of 61

Posted: Tue May 08, 2012 4:25 am
by jackssmirkingrevenge
This guy doesn't seem to mind shooting 130 gram or so shells at almost 1000 fps:

[youtube][/youtube]

Quite a kick though, and without the benefit of a muzzle brake.

Posted: Tue May 08, 2012 5:09 am
by Petitlu
I want the same!
:D

Posted: Tue May 08, 2012 6:13 am
by POLAND_SPUD
well at least he knows how to lean forward

any idea why it doesn't have a muzzle brake ?

Posted: Tue May 08, 2012 6:20 am
by jackssmirkingrevenge
POLAND_SPUD wrote:any idea why it doesn't have a muzzle brake ?
Because South Africans are pretty badass :)

There is a brake on the prototype:

Image

Posted: Tue May 08, 2012 6:26 am
by Petitlu
and you can machine an effective muzzle brake?

Posted: Tue May 08, 2012 6:27 am
by Zeus
That reminds me of the first time I fired a 12 gauge, held it like a .22 rifle.

Reckon the Neo<s>pet</s>pup comes in lefty too?

Posted: Tue May 08, 2012 6:42 am
by Petitlu
powerful but not really beautiful Neopup !

Posted: Tue May 08, 2012 6:46 am
by al-xg
Well 1000fps and 130g is "only" 6000J, which isn't much compared to some other handheld calibres.

The grip is higher and closer to the barrel axis than most designs that should also help to some extent.
and you can machine an effective muzzle brake?
It doesn't really need to be THAT effective, considering a .50AE pistol most probably generates more energy and weighs less even considering the volume discharged.


I'll agree a longer recoil stroke can be harder to manage though.
Probably why even pneumatic spudguns seem to produce more recoil than an energy equivalent firearm cartridge.

Posted: Tue May 08, 2012 7:03 am
by jackssmirkingrevenge
Petitlu wrote:powerful but not really beautiful Neopup !
One of those "so ugly it's beautiful" weapons :)
Well 1000fps and 130g is "only" 6000J, which isn't much compared to some other handheld calibres.
*cough*

130g at 300 m/s is 39 Ns

A typical 0.50 BMG load fires a 49g projectile at 860 m/s, that's 42 Ns

I wouldn't say that's "not much" in comparison.
and you can machine an effective muzzle brake?
I'm sure we could work something out, it would be more attractive than the one you currently have but I doubt it would be vastly more effective.

Posted: Tue May 08, 2012 7:19 am
by al-xg
I wouldn't say that's "not much" difference.
One also needs to consider impulse; bowling would be a terrifying experience otherwise :D

Posted: Tue May 08, 2012 7:31 am
by jackssmirkingrevenge
... and the weight of the launcher itself, stock vs barrel angle etc. In short, it's a bit more complex than just the muzzle energy ;)
bowling would be a terrifying experience otherwise
:D :D :D

Posted: Tue May 08, 2012 9:22 am
by MRR
I don't know if you guys have noticed but there also seems to be a recoil absorbing system involved. You can see it in the very first shot in the video.
The shoulder stock and the receiver move apart from each other. The gun returns into default position rather slow after a shot, which indicates some kind of gas operated spring imo.

Posted: Tue May 08, 2012 9:44 am
by jackssmirkingrevenge
MRR wrote: The shoulder stock and the receiver move apart from each other. The gun returns into default position rather slow after a shot, which indicates some kind of gas operated spring imo.
Definitely:
The entire barrel / bolt group is allowed to recoil within the polymer gun housing for about 75mm (3"), in attempt to decrease peak recoil down to manageable
A similar system is used on theNTW-20 from the same firm in order to control the recoil of a full power 20mm round:

Image

Posted: Tue May 08, 2012 5:07 pm
by Petitlu
Advancement of the look, there it is operational but I must finish dressing and shoulder protection level:

Image

Posted: Wed May 09, 2012 12:03 am
by jackssmirkingrevenge
Yep, definitely needs some padding to stop it biting into your shoulder! Looking great :)