"The national champs are the holy grail of brass bands, and we were competing against some extremely good bands.
"We couldn't have wished for better results. They were the result of two months of extremely hard work from the band," Mr Jellyman said.
He said Brass Whanganui was in a "re-building phase" and was not yet ready to move up to A-grade.
Bands compete in four grades, with A being the top and D the lowest.
Mr Jellyman said it was a big mission to get all 38 band members plus their kit - including large musical instruments such as bass drums and tubas - to Napier and back.
Watch Brass Whanganui compete in the street march here: