More a partisan than a spontoon

[Jim McDougall]

Interesting to see armor piercing on American spontoon, and this is indeed fashioned in the partisan style of Europe (16th-18thc.) with the shaped, cusped wings. In Stone, a Flemish example of 18th century (p.483, fig. 616, #18); and an Austrian (op. cit. #11) of c.1740. Neither have the armor piercing feature.
In the Wallace collection a Saxon example c.1700 similar, again no armor piercing.