Grenade Launcher under HK53????

[pretorian669]

http://jccc.afis.osd.mil/LBOX/mini/934792.jpg
Hi res (http://jccc.afis.osd.mil/images/hres.pl?Lbox_cap=934792&dir=Photo)
Does anyone know what type of grenade launcher is that?
In the original post " MAGNUM" stated it's an M-203.
http://www.militaryphotos.net/forums/viewtopic.php?t=17813
I used M203's both standard and PI.
From the picture it does not look like an M203.
Does anyone have a better picture (perhaps side picture) of this setup?

[REMOV]

http://jccc.afis.osd.mil/LBOX/mini/934792.jpg
Does anyone know what type of grenade launcher is that?It looks a little like a 40mm MK40 grenade launcher from Singapore.

http://37mm.com/launchers/images/mk40.jpg

[Supes]

Dang, a Surefire M900a on it too.

[D.E. Watters]

I believe that it may be a model from the British firm ISTEC.

[REMOV]

I believe that it may be a model from the British firm ISTEC.Hmm...

Source: http://www.steyr-aug.com/accessories.htm

http://www.steyr-aug.com/240.jpg

Description
The ISL 274 40 mm grenade launcher was developed by ISTEC to meet an Australian Army requirement for an under slung 40 mm grenade launcher to fit onto the Steyr AUG/F88 5.56 mm assault rifle. It is a manually fired, fixed breech, side-opening weapon that can be under slung from an AUG barrel by means of interface brackets. A cutaway lower hand guard replaces the standard item and can be used when the grenade launcher is not attached to the rifle. The main components of the grenade launcher are manufactured from hard-anodized aluminum alloy. Other components are stainless steel. The firing mechanism is of the double-action type. As the launcher breech is opened, the spent case is ejected automatically. The direction of opening of the side-opening barrel can be to either side to meet individual user requirements; the conversion can be carried out by the user in the field. Barrel locking levers are on both sides of the grenade launcher body.
A sight unit is attached to the grenade launcher body, graduated in 50 m increments from 50 to 300 m. The sight can be secured to either the left or right-hand side of the launcher. When not in use, the grenade launcher is carried in a webbing carrying case.

Specifications
Calibre: 40 mm
Operation: single shot
Weight: grenade launcher and sight, 1.2 kg; interface bracket, 180 g
Length: grenade launcher, 280 mm
Sights: 50 to 300 m in 50 m steps
Trigger pull force: 1st pull, 40 N; release pull, 70 N
Muzzle velocity: 76 m/s

[pretorian669]

Take a look at the shape of the launchers barrel at the muzzle end...
http://img11.photobucket.com/albums/v34/pretorian669/Image3.jpg

It’s not round like on the ones you guys posted...
http://img11.photobucket.com/albums/v34/pretorian669/Image1.jpg

Might it be an add on “don’t let your hand slip before the muzzle" type hand guard like the ones on weapons with very short barrels?
http://jccc.afis.osd.mil/images/hres.pl?Lbox_cap=934792&dir=Photo

[pretorian669]

Dang, a Surefire M900a on it too.
Yeah "HiTech" Mounting System ;)

[D.E. Watters]

REMOV: ISTEC makes other models than just the one shown for the AUG. I believe that the model mounted on the HK 53 may be the ISL 201.

[Carlos]

Yes, it is a ISTEC Model ISL201... ;)