icuham

The amount of explosive is an incredibly small fraction no matter how you try to position it. (Does the default DCS CM belt even have HE? The references above note an explosion at 700m, we don't witness this with 13mm do we?) It simply shouldn't create a similar effect to 30mm, yet the pilot of the target aircraft experiences this in the effects, particularly the pilot health model and control surfaces. The other tell tale sign is that the engine doesn't experience the same effect. It suffers much more damage from a 30mm shell than a 13mm. If 13mm HE was the explanation then how does that reconcile? To make this even more obvious, the Spitfire's .303 rounds ALSO cause explosive effects (sounds, etc). Surely that's not HE packed into a .303 round? This line of justification doesn't hold together at all for me.

Are you sure you aren't thinking of a MG151/15? The MG131 has even less kinetic energy than a Browning M2... It's HE shells aren't useful for much more than spotting... They have less than 1/10 of the explosive in a 15mm shell and 1/50 of the explosive in a 30mm. Do you think that will knock out a pilot or kill them in the explosion? The only thing smaller is the .303 rounds on the Spit (which also shouldn't explode): MG131: https://en.wikipedia.org/wiki/MG_131_machine_gun "13 mm AP-T (Pzgr. L'Spur) - 710 m/s, projectile mass 38.5 grams (594 gr), muzzle energy 989 m/kg[2] 13 mm HE-T (Sprgr. L'Spur) - 710 m/s, projectile mass 34 grams (520 gr)[3] 13 mm HEI-T (Br. Sprgr. L'Spur) - 750 m/s, projectile mass 34 grams (520 gr) with 1.4 grams (22 gr) PETN + 0.3 grams (4.6 gr) thermite, muzzle energy 975 m/kg[4]" http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-am.html "1 Panzergranatpatrone L'spur o. Zerl 1 Brandsprenggranatpatrone o. Zerl 1 Sprenggranatpatrone L'Spur Üb m. Zerl This load is a mixture of AP and HE/I with training ammunition (Übung) with self-destruct fuses! This was used in the MG 131 because it detonated after about 700m, and the flashes had a deterrent effect on attacking fighters. The relatively generous use of tracer and phosphorus ammunition in the MG 17 probably had a similar background." AN/M2 .50 https://en.wikipedia.org/wiki/M2_Browning#Ammunition http://www.smallarmsreview.com/display.article.cfm?idarticles=3055 "Further testing in the 1940’s by reducing the projectile weight from 750 grain to 710 grain increased the velocity to an incredible 2,810 (presumably f/s, 856m/s) So this ammo is nearly 20% heavier and flying 20% faster.... I assume then you are suggesting the 1.7g of high explosive is giving the 13mm round basically all of the effect? MG151/15 (yes this is a mini-cannon... It is also not on the 109): https://en.wikipedia.org/wiki/MG_151_cannon#Ammunition_specifications Minengeschosspatrone X 151 ohne L'Spur[13] HE 104 grams 25 g HE (Ha-41) 705 Nose fuze, no tracer

It is much weaker against the engine. It seems somewhat weaker against systems in so far as it doesn’t affect systems far from the impact zone, but seems significantly more damaging than other machine gun rounds to local systems. And the point of the bug report is primarily the impact to pilot health. The presence of explosion effects (sound/visual effect/pilot concussion effect) indicates the 13mm may be affecting the pilot specifically in a way that’s very different from other machine guns. What did you find upon testing this @amazingme? Did you witness explosions and concussions as a pilot in the target plane?

Additional track file from second P47 WW2-WEAPONTEST-2p-20201222-114601.trk Second additional track file from 2nd P47 WW2-WEAPONTEST-2p-20201222-121209.trk

First report: Steps to reproduce: 1. Start in flying P47 2. Push RPM lever to full forward 3. Push Throttle Full forward (note that this disagrees with the link above) 4. Push boost full forward 5. Press the RPM increase switch full forward and do not let go until the engine fails 6. At this point the flight model will fail... but how it fails may be different with each successive test and may depend on the position of RPM control lever (the further forward it was at failure or after failure the more speed the plane will accumulate) The flight model will fail with different modes: plane could experience a down pitch attitude, up pitch attitude, typically hard right yaw, possibly roll in either direction. Pilot may blackout, or not, plane may be controllable or not. What is certain is that it will not stall or lose airspeed if the steps reflect our experience. Tracks to be added. track111158 is a view from one normal plane watching a plane with the bug, 110951 and 110656 are various tests. (More work TBD here... placeholders) server-20201222-111158.trk server-20201222-110951.trk server-20201222-110656.trk

Situation: Within a multiplayer test server we used a 109 to fire extremely short (~0.1s) bursts of 13mm at a target and observed the damage resulting. The player flying the target aircraft reported explosion sounds, control system damage, and pilot damage (concussions, double vision, etc) similar to that received by 30mm shells even when the bullets hit sections of the aircraft where non-explosive rounds would not affect the pilot. We suspect that 13mm fire is being treated as 30mm fire by some subsystems within the damage model including at least control surfaces and pilot health. Steps to reproduce: 1. Launch a multiplayer server 2. One player in 109 one in a target plane (we used a P47) 3. 109 pilot fires off all cannon rounds to avoid any confusion in test (ONLY use 13mm in the test) 4. 109 pilot fires 13mm only at the target plane, specifically targeting systems like control surfaces, engine, cockpit, etc. 5. Target pilot reports damage received by hits Results: 1. Control surfaces destroyed by minimal rounds, explosion sounds are heard as though being hit by 30mm fire. 2. Pilot experiences concussion effects, double vision, and wounds and death without reasonable penetration of the cockpit area (we attribute this to 30mm style explosive damage from what should be 13mm rounds) 3. Engine does not seem to be affected similarly to 30mm rounds. 13mm doesn't seem to act like 30mm here in our limited test, but should be considered anyway. Videos and some commentary (only captured one side): https://www.youtube.com/watch?v=5cHnljJwHc4 https://www.youtube.com/watch?v=9ss2N9z6TvE https://youtu.be/FTOM53xCtN8 Track file attached. There is a de-sync it seems in the trk after the first couple passes, but the first youtube link shows a record from the shooter cockpit. 13mm-test-server-20201220-035513.trk