P-39 Cannon

[docdodj01]

A question to the experts: how can you identify the P-39 center cannon? How to see if it’s a 37mm or 20mm? I tried using the decals as a source, but it seems P-400 and P-39s had a mix of a short and long cannons.

 

I’m specifically building lt Erickson’s P-39D. According to the instructions it uses the long 20mmcannons, BUT according to my research P-39Ds used the 37mm ones

[Dave Williams]

Usually, the long thin barrel is the 20mm cannon, and the short stubby barrel is the 37mm cannon.  There were versions of the P-39D that were built with the 20mm cannon, but were built for Lend-Lease and most, but not all, were exported.  US P-39Ds normally used the 37mm cannon.  P-400s had the 20mm cannon.  I believe another way to differentiate the two versions was by the exhausts.  P-400s had 12 stack exhausts and P-39Ds had 6 stack exhausts.

 

I’ve seen Erickson’s P-39D listed as a D-1, which was one of the versions originally built for export, so it would have had the 20mm cannon, but also the 6 stack exhausts of the P-39D.  The tail number of (4)138350 fits with the serial range of the D-1

 

http://www.joebaugher.com/usaf_fighters/p39_6.html

 

Edited September 26, 2021 by Dave Williams

[docdodj01]

6 hours ago, Dave Williams said:

Usually, the long thin barrel is the 20mm cannon, and the short stubby barrel is the 37mm cannon.  There were versions of the P-39D that were built with the 20mm cannon, but were built for Lend-Lease and most, but not all, were exported.  US P-39Ds normally used the 37mm cannon.  P-400s had the 20mm cannon.  I believe another way to differentiate the two versions was by the exhausts.  P-400s had 12 stack exhausts and P-39Ds had 6 stack exhausts.

 

I’ve seen Erickson’s P-39D listed as a D-1, which was one of the versions originally built for export, so it would have had the 20mm cannon, but also the 6 stack exhausts of the P-39D.  The tail number of (4)138350 fits with the serial range of the D-1

 

http://www.joebaugher.com/usaf_fighters/p39_6.html

 

Thank you for the response! 20mm it is!