Scorpion EVO S1 pistol
A fun, potentially practical, radically upgradable, possibly 3d-printed, and relatively affordable blow-back operated pistol caliber carbine (PCC). This is potentially the most fun firearm I own, and one that is extremely easy for new shooters to use comfortably. Whether used as a home defense weapon, range toy, tool for teaching new shooters, or larping instrument; some of the myriad upgrades (many of which are quite cheap) can increase fun and utility of this firearm. This page will be periodically updated.
pistol caliber carbines (PCC) in general
- pros
- higher velocity & lower recoil vs. pistols
- quieter, cheaper-shooting, and less recoil vs. rifle calibers
- more maneuverable & lighter vs. rifles
- generally more customizable vs. pistols
- cons vs. rifles
- less stopping power
- shorter effective range
various PCCs and estimated prices
Following includes price estimates that are likely inflated due to coronageddon. Shopping for deals can obviously reduce these independent of corona. Crude estimates mainly derived from gunbroker & gun.deals.
Estimated scorpion prices (in early 10/2020):
- scorpion without brace ~$900 to ~$1.2k (pre ‘rona ~$750-$850)
- with SBT brace ~$1.1k
other PCCs:
- more expensive
- Kriss Vector (~$1.7k)
- H&K USC (~$1.8k)
- SIG Sauer MPX - gas piston
- MP5 clones
- Zenith Z-5RS (>$2k)- roller-delayed blowback
- Beretta Cx4 Storm
- PSA’s AKV (~$1.5k)
- B&T arms
- GHM9 (~$1.7k w/o brace)
- APC9 (~$2.6k w/o brace)
- less expensive
- Ruger PCC (~$750)
- Hi-Point 995TS (~$400)
- Kel-Tec SUB-2000 (~$600)
- AR-9 - blowback
- e.g. PSA’s offerings
- stribog (~$1k with brace, pre ‘rona reported ~$600s)
history & variants of scorpion EVO
-
called the “third gen” of scorpion submachine guns, where 1st = Skorpion vz 61
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EVO series is, however, completely unrelated to Skorpion model
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EVO evolved from prototype submachine gun by Laugo firearms company
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A1 variant = automatic fire: ~1100 rpm with folding / telescoping stock
semiauto versions (“S1” & “S2”)
I own and recommend the S1 pistol. The pistols are easier to maneuver compared to the carbines and don’t become super long for a PCC if you suppress in the future. I’m can’t envision the reduced-recoil and increased velocity of the carbine (vs. pistol) being useful for much aside from allowing you to have a full-on stock without giving the vile ATF $200.
- S1 variants
- carbine: longer barrel to comply w idiotic USA federal firearm regulations
- pistols: short barrel & no stock
- colors
- +/- faux suppressor
- handguard configurations (depending on barrel length & whether have faux suppressor)
- S2 “micro”: shorter barrel
3d printed scorpions
- designs to be released soon by team “Are We Cool Yet?" (on keybase) - prototypes:
malfunctions
There have been rare reports of potentially-dangerous CZ scorpion malfunctions - specifically out of battery detonations that permanently damage the receiver. It seems as though this is a result of tyrannical US federal regulations requiring alteration of the fully-automatic design in way that makes the gun less safe (removing the full-auto disconnector that normally helps prevent out of battery firing), and CZ not fully accommodating this change with regard to safety. That being said I and many others have fired many thousands of rounds through our scorpions without issue. Furthermore, the Scorpion is likely not unique vs. other PCC’s derived from submachine guns, where we may know of these reports more simply due to the popularity and prevalence of Scorpions. Potentially predisposing factors to out-of-battery malfunctions: bump-firing, extremely fast shooting, poor quality ammunition (Blazer aluminum in at least one malfunction), debris in the action. Holding the magwell might increase risk in event of such a rare malfunction.
Further reading on such malfunctions:
- Most comprehensive discussion including trebuchet durability testing (if vid available see ~5 min in)
- controlled demonstration of out of battery primer strike & detonation
- field catastrophic malfunctions:
- discussion including how CZ scorpions are not only PCC affected by this issue
upgrades
My 2 favorite upgrades are the ~$9 trigger spring upgrade and the ~$30 ak-style safety lever.
- magazines
- cz 20 round
- these are still useful despite the existence of e.g. 30 & 35 rounders due to how compact the whole firearm is with 20 round mags inserted (e.g. for backpack carry) - i.e. you may not be able to fit the pistol in carry bags with larger mags inserted
- may not drop free vs. larger/newer versions
- cz 30 round: new version (black windowed) ~$30, old version (smokey translucent) ~$20
- I am favoring the new version as my preferred mag as they seem to seat and drop free easier than the magpul mags. Main cons are 5 less rounds and obviously the price.
- on differences between new & old:
- magpul 35 round: ~$20
- generally seem to work well (including drop-free for me), but there have been reports of improper seating. I have had improper seating ~2-3x when mag is not forcefully inserted on a closed bolt and it appears seated when it is not (and first round in chamber will drop a full mag). Strong insertion seems to avoid. Reports from others of issues:
- https://pistol-forum.com/showthread.php?39068-REVIEW-Magpul-PMag-35-rd-for-CZ-Scorpion-Evo-3
- https://www.m4carbine.net/showthread.php?218491-REVIEW-Magpul-PMag-35-rd-for-CZ-Scorpion-Evo-3
- cz 20 round
- trigger group
- reduced weight spring ~$9 https://hbindustries.net/store/shop/cz-scorpion-evo-3-s1-reduced-weight-trigger-spring-kit/
- safety selector
- sling & mounts
- I opted for simplicity: HK-style hooks to keyring on front metal sling mount region & to paracord on rear polymer sling mount
- note you may wear/damage the polymer sling mount regions even with keyrings
- there are aftermarket methods for installing QD socket mounts - these have drawbacks:
- installation on brace - makes for awkward brace folding
- installation in polymer sling mount region - may predispose to receiver cracking/damage
- I opted for simplicity: HK-style hooks to keyring on front metal sling mount region & to paracord on rear polymer sling mount
- charging handle
- prostock $35 https://hbindustries.net/store/shop/cz-scorpion-prostock-charging-handle/
- extended charging handle >$50 https://hbindustries.net/store/shop/cz-scorpion-evo-3-theta-extended-charging-handle/
- delta extended >$50 https://hbindustries.net/store/shop/cz-scorpion-evo-3-delta-extended-charging-handle/
- mag release
- prostock $26 https://hbindustries.net/store/shop/cz-scorpion-prostock-mag-release-lever/
- duckbill $30 (polymer) https://hbindustries.net/store/shop/cz-scorpion-duckbill-mag-release-lever/
- magpul
- strike industries
- tandem cross titan
- grip
- pakse pathfinder black/fde: https://hbindustries.net/store/shop/cz-scorpion-pakse-pathfinder/
- yetiwurks black/gray/alt: ~$40 https://hbindustries.net/store/shop/cz-scorpion-yeti-wurks-grip/
- magpul: ~$25
- sights
- the world is your oyster - many options
- I opted for the holosun 510c - I like these though they will not cowitness with the scorpions irons
- handguard - many options & I haven’t experimented yet
- lights
- suppressor mounts:
3d printed
media people on upgrades
- Garand Thumb https://www.youtube.com/watch?v=6zBpO7PqxuA
performing upgrades
- basic takedown
- pull bolt back
- remove lower trigger assembly: takedown pin out, then push lower back and down
- remove bolt: hold front of bolt firmly and then easy bolt handle forward while pulling bolt down
- trigger pack takedown note
- older scorpions may have the trigger pack screw welded in place
- newer scorpions secure the screw with very large amount of loctite compound - taking this down for the first time requires much force and caution is warranted to not strip the screw
more detailed gunwork
main assembly groups
- main frame
- handguard
- barrel
- trigger
- bolt
- sights
- grip
- brace / stock (optional)