Since we're big proponents of torquing and staking castle nuts to ensure their immobility, not only have we designed a castle nut (CNF, or Castle Nut FCD) to make staking more secure, but also a dedicated castle nut wrench (JCW, or Joint Castle nut Wrench), it only makes sense we should offer the proper tool to stake it.
Derek Fightmaster at Ammozone has produced a superb video that aptly demonstrate the way to stake a castle nut:
https://youtu.be/V9S3OFbVYxI
Of the suitable punches, we opted to carry the Mayhew 5/32 x 4 1/2 punch, which happens to be the punch of choice of the late Will Larson (Semper Paratus Arms). In a way, it's one of our ways of carrying on a bit of his legacy.
Item Description: 5/32pt OAL=4-1/2?
Weight: 0.09
Width: 2.000
Length: 4.500
Height: 1.000
Cut Width or Point Size: 0.156
Taper Length: 0.000
Country of Origin: US
Rockwell: 55 – 57