Three Sides, Four Sides, Why Not Five Sides

[nkbj]

When the US government adopted three groove rifling subsequent to the findings of the small arms commission headed by Jefferson Davis it pretty much set the standard until percussion long arms were retired. So, it got me to wondering how did that choice effect bullet designs in the system engineered for combat use? Clearly it was best suited to lubed lead bullets as opposed to the tapered depth five grooved barrels adopted by the British, their barrels being well suited to the paper patched bullets. Looking around for what bullet designs were in use I stumbled onto three and four sided base cavities used by the French.

Oh yeah there's a lot of systems engineering that went on this arms race!
So, anybody have any guesses on what advantages may have been offered by not using round base plugs?

 

[Phil Coffins]

I rember hearing that “the French copy’s no one, and no one copy’s the French! “
That said it was a time of exploration and it seems that anything would be tryed. A lot of dead ends due to the fame or over powering personalities came and went.

 

[nhmoose]

3 groove are faster to make and thus cheaper for the same reasonable accuracy. Govt always picks the cheapest they find works the same. Unless buying hammers and toilet seats.

 

[nkbj]

Maybe if you had three big grooves then eh, maybe a three sided base plug offered some advantage. Perhaps the reinforcement helped with preventing blow skirts and skirt rings left behind in the bore. Beats me so thought I'd ask.