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By dune
Published: 15 January, 2004
Special thanks to: Icefire Enterprises
Opening the Box/Initial Impressions
The KWC Smith & Wesson Sigma SW40F comes nicely packaged as a complete kit
including:
- Sigma SW40F sidearm w/ Hop-Up (Weight: 846g)
- One 25 round magazine
- Valve adapters and tools for CO2 or Green Gas operation
- Remote disconnect assembly for CO2 operation
- Bag of 100 .20g rounds
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| A close of the box. |
All items included in the package. |
Overall the gun has a remarkably solid feel and balanced weight, much like the
real steel. Both the main body and slide are constructed of high quality ABS
plastic that is approx. 2-3mm thick. The single-piece grip is rather comfortable
and is textured on the front and back to ensure a firm grasp. The barrel and
breach is a solid metal piece with a brushed aluminum look. While the gun does
ship with an orange plastic tip, it can be removed to reveal a threaded barrel
for supporting a silencer. The 25-round magazine has a metal exterior and
carries a substantial weight that adds to the overall feel and balance. At the
bottom of the mag is a threaded hole to support the interchangeable CO2 or green
gas input valves.
Configuration/Features
Up until recently most gas blowback side-arms ran almost exclusively on green
gas (or duster gas). However, due to its limited availability and flammable
nature we are starting to see several new models capable of supporting both
green gas and CO2. Although CO2 expands slower than green gas it has a higher
PSI making it too powerful for traditional plastic gas pistols. The metal
components in the SW40F reinforce the magazine and breach allowing it to handle
higher pressures.
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| CO2 compression fitting. |
CO2 quick-disconnect valve. |
Full setup for CO2 operation. |
Changing between CO2 or green gas operation is very simple but is not an
"on-the-fly" procedure and should be done prior to any extended use. The package
includes two valve types, one for the CO2 system and one for green gas. A
threaded hole at the bottom of the mag allows you to insert and remove the
valves as needed. The CO2 valve can be attached by hand but the smaller green
gas valve requires the included tool or a flat-head screwdriver to fully secure
it in the mag. Since the ability to run CO2 or green gas lies solely in the mag
configuration, one could purchase extra magazines and configure them for either
method of operation.
The slide uses a standard 3-dot fixed alignment system for sighting your target.
There are two mounting screws underneath the barrel section for attaching a
laser sight as well. The slide is removable for service and maintenance of the
sidearm.
Green Gas Operation
Once the valve is properly installed in the magazine it is filled just like any
other gas blowback sidearm. The clip holds approx. 25 rounds and enough gas for
about 40-50 shots depending on your rate of fire. Again, the grip and weight of
the gun is quite comfortable, well balanced and easy to work with. With a fresh
clip and full fill of green gas the first 5-10 shots (with ~5 second pause
between firing) are rather powerful with a firm recoil and full cycle of the
slide.
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| Mag configured for green gas. |
The breach. |
Loading up the mag. |
However, after only 10 shots I ran into one of the largest issues I have with
the gun, the slide. Overall the slide is heavy and sometimes fails to cycle
completely partially because of the weight but also because of a small metal
roller underneath the bottom of the slide (pictured below). It’s clear the
roller is supposed to allow the slide to close normally but this would stick
about 5-10% of the time while shooting. If the shot produces a full recoil the
slide is kicked back far enough to come back fully. However, if the gas cannot
provide enough force to kick the slide back fully there is a potential of it
getting stuck in a half-cocked position (shown below) where you cannot fire and
have to manually re-position the slide. I attempted to lubricate the roller with
some silicone oil which improved the issue somewhat but didn’t resolve it
completely.
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| Slide stuck in "half-open" position. |
Point of roller friction. |
Overall the majority of the shots were consistent and accurate to about 15-20
yards with .20g. For comparison the mag seems to hold a significant amount of
gas, more than my TM M9 Tac Master but produces the same number of shots. Each
shot clearly uses more gas and I noticed my canister was somewhat depleted after
only a few refills.
CO2 Operation
Before I get into the details I want to state that this gun was clearly designed
for CO2 operation. The re-enforced metal parts and overall operation with CO2
produced a night and day comparison with green gas.
For CO2 operation, The SW40F has a remote holder for the CO2 canister with a
quick disconnect valve up near the magazine. The remote assembly accepts
standard CO2 canisters that are also used in traditional .177 caliber BB guns
and readily available in the US. Simply unscrew the bottom part of the holder,
insert the cartridge and tighten back up to puncture the canister and start the
airflow. Because of the valve this can be done while connected or disconnected
from the mag. The holder has a belt clip for easy handling. The tubing was a bit
awkward but didn’t cause any problems.
I knew by first few shots would be more powerful than with green gas but I had
no idea. I went right for the bottom of a Pepsi can and the first two shots went
right through, no problem (see below). Curious, I went for the side of my plastic
garbage bin… oops. Normal shooting was improved as well. The recoil was much
harder and the problem with the slide sticking was only an issue when the
canister was near empty. Overall accuracy was also improved slightly since each
shot was very consistent with a full cycle of the slide.
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| Remote holder clipped to pocket. |
350-375+ fps?? |
Rest in pieces. |
A full cartridge also yields about 40-50 shots, again depending on rate of fire.
I would recommend spacing each shot further apart with CO2, allowing the gas
time to expand fully. Rapid firing is however not an issue if/when needed but
you probably will get closer to 30-35 shots.
Conclusion
With a street price around $100-$120, this gun is a great addition to anyone’s
collection. With its impressive build quality, reliable performance and
adaptability to both green gas and CO2 it truly is an unbeatable value. As you
probably gathered I would personally use this side-arm in CO2 mode almost
exclusively for trustworthy performance in a firefight but the gun performs well
in either mode.
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| Close-up of pistol and mag. |
Slide removes easily
for maintenance. |
Pros: Solid feel, balanced weight, reliable operation on Green Gas or CO2
Cons: Green Gas mode not as powerful, CO2 system requires remote holder, slide can stick during cycle
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