Both BREN S1 and MSBS/GROT
S16 FB-M1 are gas operated,
short-stroke gas piston rifles with
multi-lug rotating breechblock.
And that's the common thing for
them. Let's discuss the differenc-
es.
BREN S1 in its basic configura-
tion had 16" barrel (there were also
11" and 14" barrels available as an
option) with muzzle device and
bayonet attachment lug on the
gas block. Surprisingly, the bayo-
net might be properly attached to
the 14" barreled rifle, because the
hole in the bayonet's guard will not
lock properly over the muzzle de-
vice. Civilian GROT comes with 16"
barrel without the bayonet lug.
CZ BREN S1 has single stage
gas regulator with two settings: for
shooting and for disassembly. To
change the setting, the safety pin
with spring must be pressed down
what allows to rotate the regulator.
Then, stroke, piston guide rod and
spring might be removed. GROT
has two-stage gas regulator with
normal setting and over-pressured
one for shooting with dirty gun.
Unfortunately, its "maintenance"
position is not secured or locked
in any way. The GROT gas system
looks simpler, but the removal of
piston is more difficult.
Barrels in both rifles are easy
to replace, but GROT has a way
B R E N S 1
BREN
gas block
Bottom mounting rail
Sights unfolded
left side levers
www.fragoutmag.com
