Why aren't boattails used more often?

I see there are lots of advantages of a boattail even if it adds some extra work on manufacturing. However, I see lots of rockets without it. Is there any other reason/detail I’m missing here?

AliHabes said:

I see there are lots of advantages of a boat tail even if it adds some extra work on manufacturing. However, I generally see lots of rockets without it. Is there any other reason I’m missing here?

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I would guess that it's because it isn't really helpful on rockets where you want performance. If your rocket's diameter is large enough for a boattail, you can just make the diameter smaller. If ypu need to launch a wider payload, you can just put the transition at the top.

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Is the extra work worth the 'coolness factor'?

(for a gain that can be gained in another way?)

I love a nice boat tail if for more than aesthetics. Long, short, conical, I love them all. The best use for me is when the motor retention is integrated.

There are a few casings with boat tails ( CTI 29mm ) as well as some that can be toploaded ( AT 18mm SU ).

On an experimental basis many reloads can have their aft closures turned down

AliHabes said:

I see there are lots of advantages of a boat tail even if it adds some extra work on manufacturing. However, I generally see lots of rockets without it. Is there any other reason I’m missing here?

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Boat tails create additional challenges with installing and retaining RMS motors (AT, CTI, etc).
While a simple metal lever is enough for retaining Estes engines, you do need and want a positive retainer to keep the engine casing in place when the ejection charge fires.
Most of the commercial and DIY retainers require access to the area around the MMT aft end, and that is the same area that is otherwise blocked by the boat tail.

Special arrangements can be made to accommodate a boat tail and a motor retainer, and there is at least one boat tail retainer on the market. But it all makes for a tight and tricky fit at best, and does not work at all at worst.

Other than that, boat tails are great. I built a few on smaller rockets that I wanted to go high.
On the bigger HPR rockets my problem is the opposite - keeping them low, below the FAA waiver. So boat tail is the opposite of what is needed there...


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Aero pack makes beautiful tail cone retainer combination in pretty much all high power sizes. They are a bit more expensive than their standard retainers but look and work great. I have one on my adventurer 3 (3" rocket with 54mm motor) rocksim didn't show much difference in performance on this rocket but it looks cool!

I like turning boattails from 6061. Giant Leap used to market a boattail with an integrated "Slimline" retainer. Those are gone, but I still make boattails to fit over their standard Slimline retainers. I can't quantify that they improve performance, but they do look kool.

LithosphereRocketry said:

I would guess that it's because it isn't really helpful on rockets where you want performance. If your rocket's diameter is large enough for a boattail, you can just make the diameter smaller. If ypu need to launch a wider payload, you can just put the transition at the top.

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A boatail reduces aerodynamic base drag, so it most certainly is a performance device. Transitions increase drag.

cherokeej said:

I like turning boattails from 6061. Giant Leap used to market a boattail with an integrated "Slimline" retainer. Those are gone, but I still make boattails to fit over their standard Slimline retainers. I can't quantify that they improve performance, but they do look kool.

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I just bought and received a ogive boattail retainer from Giant Leap...

Hmmm... Those are new. Ogive, no less. Nice.