The original K-47 and the EARLY 1247 used the BT-55V.
The 1247 changed to the full-length 18" BT-55 right around the same time it changed from a BNC-55AC cone to the PNC-55AC cone. I have NEVER seen a kit with the plastic nose cone and short tube, nor have I seen a kit with the balsa cone and long tube other than a clone.

It is MUCH more stable with the long tube. If you want the short-tube version, use plenty of nose weight.

I personally think the long-tube version looks better.
The Cherokee-D was my first D-power rocket and I have lost more of them than any other rocket.
An 18" chute on a rocket this small and flies so high is JUST PLAIN DUMB.
A 12" is plenty and use that with a D only in very light wind. Otherwise, use a STREAMER if u want it back.
Interestingly, the only time I have lost them has been using the D12-7.
Never lost one on a D12-5 or on the long discontinued D11-9. The D11-9 is about a perfect motor for the Cherokee-D; it has a little less total impulse than the D12 and the 9 second delay is about perfect with a streamer.

I actually flew one on an Aerotech E15 with streamer recovery in zero wind and got it back. Landed within 100' of my backyard pad. I think that thing must have hit at least 3000'.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !