The Cherokee - D Kit # 1247 shows a BT-55V tube. Further research indicates that the V designation was for a BT-55V tube that was 16.35 inches long. The 16. 35 inches converts to 16 23/64 or 16 3/8 inches The 23/64 is 1/64" short of 3/8 inches.

Here is the Estes link to the Kit # 1247 Pdf.
http://www.estesrockets.com/media/i..._CHEROKEE_D.pdf

Semroc part list for the K-47 Cherokee-D kit also shows the BT-55V tube.

http://www.semroc.com/store/scripts...Parts.asp?ID=56

__________________
David Manning
SAM # 0455