Swapping over to the Soviet fighters. Here's an example of the level of toughness I think that an inline engine fighter should have against long-range rifle caliber bullet hits.
The target is a Yak-1, the gunners are more of those crazy accurate Wellington III Ace tail turret guys, this time doing their thing at ranges of anywhere from 700(!!) to 300 m against a slowly maneuvering target.
http://forum.1cpublishing.eu/attachm...1&d=1403464421
What you will notice is absence of smoke and flames, and an engine which still runs pretty well.
This picture actually represents the second and third bursts of long-range gunfire into the engine. The first burst had about 3 scattered hits into the engine block, all hits which would have had a Bf-109 or P-40 engine shut down cold or spewing clouds of black smoke.
A fourth burst of gunfire actually shut down the engine, but I was able to start it back up and continue the fight. A fifth burst of 3-4 shots eventually made the engine lose enough power that I couldn't keep up with the bombers, but I was still able to fly back home.
Further testing basically proves the same thing - the Yak-1 DM makes its engine a lot tougher than other contemporary inline engined planes. So, there is at least one inline fighter in the game which doesn't die instantly when it gets hit in the nose. I will leave it to TD to determine if this is intentional or not.