Big Bertha vs FatBoy nose cones for upscale

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Well-Known Member
Aug 28, 2007
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I have a AMW Big Bertha upscale kit that is half built. Started it years ago and then 2 fins curled (1/4" birch plywood) and I abandoned the build at that point as it would surely fly rather goofy.

For whatever reason, I held the NC up to my 4" Wildman and low and behold, the NC matched exactly. Matched the couplers as well. Then it occurred to me that the NC is likely a Curtis NC so it makes sense then why it likely matches.

The next thoughts that came to mind are "OK, what can I convert this to that is all FG?!?" And then idea then was I could build a 4" FG FatBoy.

My question though is.....are the Big Bertha and the FatBoy the same shape? It looks like the Big Bertha is more of a fat ellipsoid where the FatBoy is darn near a hemisphere. I could be wrong though.

Does anyone have any insight on this?
The current PSII Super Big Bertha and the long OOP Fat Boy (and the OOP Mega Mosquito) use the same BT-80 nose cone. Current production Big Bertha, Mini Bertha and recently OOP Mini Fat Boy all use the same BT-60 nose cone. I have no idea about any non-Estes products inspired by or upscaled from these.
Thanks for the feedback and verification, guys!

Looks like like my AMW Big Bertha is going to transform into a 4" AMW/WM FatBoy!

Either that or build a FG Big Bertha.