SIGforum
What operating system does this rifle use?

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/630601935/m/2290071594

September 30, 2022, 11:42 AM
KSGM
What operating system does this rifle use?
https://www.recoilweb.com/tinc...a-review-176562.html

The author refers to it as short stroke piston, but it looks like long stroke to me, just with a very short op rod. If I am correct, how does this design do anything special? Seems like it would dump excess gas into the receiver. How do y'all interpret this? Weird gun either way.

This message has been edited. Last edited by: KSGM,
September 30, 2022, 05:54 PM
Exodus
Pretty sure it is a short-stroke.

The gas tube feeds into a gas block with a short piston. It operates the short piston which smacks the long piston/op rod that's attached to the BCG.
September 30, 2022, 06:14 PM
Oat_Action_Man
Ian from Forgotten Weapons also describes it as short stroke (starting around 6:30 into the video):

https://youtu.be/zFR2zHfLZqc

Good video, as always, where he shows the actuation of the piston and bolt. 15mm of piston travel, according to him.


----------------------------

Chuck Norris put the laughter in "manslaughter"

Educating the youth of America, one declension at a time.
September 30, 2022, 06:23 PM
KSGM
Ah! I see. I was right in thinking there was no room for a piston in that block. Clever.
October 02, 2022, 08:38 PM
darkest2000
On a side note, I was kind of excited about this rifle but somewhat lost interest after finding out that the U.S. version comes with a plastic lower receiver as opposed to alloy that the original has.

Seems like a strange choice seeing that tooling up for injection molding isn't exactly all that cheap either.