Blyskawica: Poland’s First Successful SMG Design

Polish Underground clandestinely manufactured SMG: the Blyskawica.

Making the rear surface of the barrel plug and bolt’s front facing surfaces convex is another interesting feature of Blyskawica, enabling the dirt to accumulate there without hindering the action.  Both surfaces scarcely made contact except for dry-firing, as the Blyskawica employed an advanced primer ignition scheme, common for submachine guns firing from an open bolt.  In connection with the bolt ribs, it proved especially useful in urban warfare during the Warsaw Uprising when there was plenty of rubble and tons of brick dust in the air, enough to jam most other, more renowned submachine guns.  Breechblock cylinders were turned on a lathe in pairs, disguised as shafts.  Then ribs were machined into these, and spring channels drilled into either end.  After these operations, the ribbed hollowed ‘shafts’ were cut in two on a lathe, using a triangular-shaped cutter tool, then all other openings (for the extractor claw, dovetailed cocking handle slot, bolt face with a firing pin shaft) were executed.

The trigger mechanism is of very simple, bordering on crude, design but nevertheless fitted with an advanced automatic trigger safety.  The spring-loaded safety forms a part of the trigger linkage.  The safety lever extends into the trigger guard, while the nose of the safety is inserted into a notch in the trigger mechanism casing, thus immobilizing the trigger.  To operate the sear, the shooter has to insert his finger between the safety lever and the trigger to unblock the latter.  There is no means to make the gun safe with the bolt closed or retracted – in fact, apart from the automatic trigger safety; there are no further safeties at all.  This was infamous as a very failure-prone safety, though, and many accidental discharges were noted after bumping the stock on the rubbles in a ruined city.  There is no fire-selector either, but the heavy bolt kept the rate of fire low enough to make squeezing-off single shots relatively easy.

The stock is folding, twin-strut, with struts made of steel flats with a cast aluminum stock plate.  The stock is folding underneath the receiver, and its length of pull is governed by the measurements of the receiver, which makes it a little short for the average shooter.  A different butt-plate, hollowed to clear the magazine (like in AKS-47) would have helped to lengthen the stock.  Here again the influence of the MP 40 is obvious – it folds under the receiver, even though a top-folder like the Soviet PPS 42/43 or a side-folder, like Reising 55 or Sten Mk IV, would enable to use a longer, more comfortable, stock.

Trigger and trigger safety lever inside the trigger-guard.

The sights were rudimentary, with a peep rear sight and an inverted V, very low front post, difficult to shoot precisely at anything more than possibly 30 yards away.  These are clearly patterned after the Sten sights, but reveal precious little experience with the peep sights on part of the designers.  This is hardly surprising, as these were a novel feature for the Polish military weapon – in fact Błyskawica was the first and only Polish peep-sighted martial firearm until the advent of the PM-84P of 1990s.  The peep itself was much too wide, of almost ghost ring proportions, while the pyramid front post was way too small, making it almost impossible to aim precisely.  The peep is located on the receiver plug stop, on top of a dovetailed projection of the lower receiver, while the post is situated on the barrel plug, bolted to the receiver.  The placement of sights on separate parts with a degree of play between them made precise aiming difficult, because it was possible to assemble the SMG with sights out of the line.

The magazine is of typical Schmeisser staggered-row, single-position system, widely employed for the German (MP 28, 38/40/41), as well as the British (Sten, Lanchester), the American (M3 Grease Gun) and the Soviet (PPSh 41) SMGs of the era.  It has a wide body, containing a staggered row of rounds, culminating with a conical upper part, channeling the two rows into a single position feed.  Inside the body runs a sheet-metal follower, actuated by a follower spring.  The magazine is closed with a magazine bottom plate, locked by a projection of the spring pressure plate inserted into the bottom plate opening.  Most reliable and coveted were the airdropped originals, as the Polish copy thereof often lacked in quality, mostly because of the follower springs made of improper – but readily available – wire.

Action of the Mechanisms
With the loaded magazine in place and bolt (5) retracted, the gun is ready to fire while the automatic safety (21), incorporated in the trigger mechanism, renders it (relatively) safe.

With firing finger inserted between the trigger (11) and the safety lever, the latter is being pushed forward, thus extracting the blocking projection from the matching notch in the trigger mechanism casing (25) and putting the safety off.  Upon pulling the trigger, it is rotated forward, pushing on the trigger bar (10), which rotates the sear (9) in turn.  The sear nose is thus being retracted from the sear notch, freeing the bolt to move forward under the power of both driving springs – the long one (6) actually propelling it, with bumper spring (8) helping to overcome the inertia.  The bolt is chambering the cartridge from the magazine, firing it while still en route to the forward position.  The expanding gases throw the bolt back, compressing the driving spring.  If the trigger is released, the returning bolt engages the sear and thus the firing cycle is interrupted.  If the trigger is held back, the cycle repeats itself until there are no cartridges in the magazine.  There is no bolt hold-open device, so after the last shot is fired the bolt rests closed.

Upper receiver rear plug with concentric return/buffer springs.

Elementary Disassembly Procedure

1. Unload, clear, check and double check the weapon.

2. Unscrew receiver end plug bolt.

3. Unscrew the lower receiver retaining screw, then slide down the lower receiver until it separates from the upper.  NOTE: the actual Blyskawica in the photos was shrapnel-damaged and the field-repair includes replacing of the torn-off retaining screw bracket with a curved brace held by two side screws.  Check the cross-section drawing for correct shape and position of the retaining screw.

4. Unscrew the upper receiver end plug and withdraw the springs.

5. Unscrew the cocking handle retaining screw, separate the handle from the bolt and remove, then withdrew the breechblock.

6. Unscrew the barrel jacket and pull the barrel out of the receiver.

7. If necessary, unscrew the trigger pack retaining screws from the lower receiver and take the mechanism casing out.

No further stripping is needed or recommended.

To assemble, reverse the above procedure.

Imperfect, But Genuine
For years the Blyskawica has often been mistaken for a German gun, which it never was.  Even if authors do recognize the Polish pedigree of the gun, they most often mistakenly label it as a Sten copy (see World’s SMGs and Machine Pistols Vol.2a) – which is simply not true.  The only Sten parts were magazine and barrel incorporated into the design only because these parts were already being series-manufactured by the underground factories in huge quantities, and their choice was governed by logistical factors, not a need, or desire, to copy them.

The chief disadvantage, especially in the dusty urban warfare conditions, was a time-consuming and complicated field-stripping procedure, calling for driving out numerous, small, easy to loose screws.  The micro-grooved threads were vulnerable to dust, often jammed and got torn-off during field-stripping or reassembly by use of the excessive force.  The worst idea of it all was the aluminum barrel jacket.  In theory, it was designed to transfer and dissipate the heat from the barrel, but in practice no one in the underground had enough ammunition to make the barrel glow.  The downsides of the aluminum barrel jackets were many, but two should be enough to get rid of it.  First, it was left “in the white” and shined on, prematurely warning the enemy of the shooter’s position.  This is confirmed by the original Warsaw Uprising photos – in most cases a shining barrel jacket is the first thing enabling us to recognize the Blyskawica submachine gun held by an Uprising soldier.  Second, it was held by the same micro-grooved thread that secured all other components, and thus – if the dirt was enough to jam and damage the threads cut into steel components, then steel thread was sure to wear and tear the aluminum barrel jacket.  These were frequently damaged, and after the threads were obliterated, the gun could be thrown away as well since it was the barrel jacket that held the barrel inside the receiver and took the hammering from the heavy bolt if dry-fired.  Some late September and early October 1944 photos show at least one Blyskawica fitted with an exposed barrel and a short steel plug screwed into the receiver instead of the aluminum barrel shroud.

One of a handful of lighters marked to commemorate the christening ceremony of the Blyskawica in November 1943.

The abysmal sights could have been easily rectified by placing both sights onto the upper receiver.  The sighting radius would be shorter by no more than an inch, and both would be finally placed in line.  With a smaller peep and higher, pillar-contour, shrouded front sight, the Blyskawica would be very nice to shoot and a lot more accurate gun.  When I fired a rare shootable survivor (held at the Police HQ Forensic Lab, unfortunately not allowing any photography) I found it a real pleasure to shoot, well balanced, and grouping nicely – even if a foot up and to the right off the aiming mark at 15 meters.

For no obvious reason the cocking handle of the Blyskawica was a very complicated affair, set into a dovetailed machined channel on the outer surface of the bolt and screw-retained there, with no provisions for securing the cocking handle in front or retracted position to preclude accidental discharge (AD) incidents.  This is unreasonable at best, especially as the Sten with its rod-like cocking handle was one of the ‘organ donors’ – by copying of the Mk 5 push-thru handle with its projection inserted into the receiver hole, many later accidents could have been avoided.

But generally speaking, for the first gun ever designed by the two men never even remotely connected with the firearms industry, this is a remarkably original and successful design feat.  Despite the primitive technology, surviving examples seem to be of exceptionally good workmanship and standard of fit and finish.

These guns were not enough to win the victory for the insurgents, who fought a 63-day long gallant and deadly battle after being left to their own devices by the approaching Soviets, who were watching idly the city’s ordeal from the other side of the Vistula River.  Stalin ordered his huge summer 1944 offensive to a screeching halt, in order to let the Nazis sort out the Poles before he occupied their capital.  Betrayed insurgents paid a tremendous price for their audacity, as the Germans pummeled the city with shells, bombs, arson, and controlled demolition (often on top of the inhabitants herded into cellars prior to explosion).  Around 200,000 people died, 90% of them civilian non-combatants, caught between the rock and the hard place.  The Western Allies were unable – or unwilling – to make Uncle Joe change his mind and save Warsaw.  About 700 submachine guns, be it even of the most technically advanced mode, were not enough to secure the victory against such tremendous odds.

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