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