Guns, guns, guns
Let’s be honest, if you come home from a COIN mission with rounds left in the gun, you have to ask yourself - did I try hard enough?
Let’s have a look at the fuselage-mounted gun options. The L-39 comes with a twin-barrelled 23 mm Gryazev-Shipunov GS-23L autocannon. The C-101 has the options of a single 30 mm DEFA 553 autocannon or two AN-M3 machine guns. Some general statistics of the guns are shown below:
| Caliber (mm) | Rate of fire | Muzzle velocity | Cartridge | Rounds carried | Rounds per sec | Total firing time | |
|---|---|---|---|---|---|---|---|
| GS-23L | 23 | 3400 (max) | 715 m/s (2350 ft/s) | 23x115 mm AM-23 | 150 | 56.67 | 2.65 |
| DEFA 553 | 30 | 1300 | 815 m/s (2670 ft/s) | 30x113 mm NATO | 130 | 21.67 | 6 |
| AN-M3 | 12.7 | 1200 | 890m/s (2910 ft/s) | 12.7x99mm NATO | 440 | 40 | 11 |
Due to the DCS damage model, I’m going to focus on the autocannons - if I get around to it, I might play with the machine guns but I don’t think the combat effectiveness of the MGs is likely to be on par, so we’ll compare (French) apples with (Soviet) apples first.
The GS-23L and the DEFA 553 are quite different:
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The GS-23L is a ‘Gast gun’, i.e. a twin-barreled weapon in which the firing action of one barrel operates the mechanism of the other. It is powered by the recoil of the floating barrels, hence it needs no external power source to operate.
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The DEFA cannon is a gas-operated five-chamber revolver cannon using pyrotechnic cocking and electrical ignition.
GS-23L at the top, DEFA at the bottom
So - the designers have approached the same problem with quite different solutions. Does it matter in the cockpit?
Looking at the numbers, the biggest difference on paper is the rate of fire. The twin-barrel Gast gun mechanism gives the GS a substantially higher rate of fire, 3400 vs 1300 rounds per minute. You can look at this from quite different perspectives - on one hand, you get more passes with the DEFA as your total trigger-down time is a lot longer, on the other, in theory with the GS a shorter burst will do and you’ll get more rounds on target in a shorter space of time.
This will require some field testing. Stay tuned.
