hi

Hey Dan,

Great observation - this definitely lines up with some quirks I’ve seen on Slingerland shells over the years. From what I understand, there can be a very slight difference in the outer diameter between M (natural finish) and P (wrapped) drums, mostly due to how the outer ply is sanded and finished. On M drums, that clear-finished mahogany outer ply is often left a little thicker to maintain the integrity and appearance of the wood grain, whereas on P drums, they might sand it down slightly more to accommodate the thickness of the wrap (which adds about 0.03"–0.05", depending on material).

So while the actual ply count is usually the same, the effective OD on an M shell could be just a hair larger -enough to make hoop fitment tighter, especially on older drums where the wood might have subtly swelled or the hoops dried/shrunk a bit over time.

You’re not imagining it - it’s a small detail, but it can definitely affect things like hoop fit and finish wear when trying to slip them on for shipping.

Cheers,

On Slingerland M drums, like your clear-finished mahogany bass drum, the outer mahogany ply is typically lacquered, which adds a thin layer of finish.