how many post you need to get to the last rank?
I think every hundred posts is a rank up. I’m not exactly sure how the system works, but here you go for the Recruit ranks. Once past the ODST ranks, I think you get a signature.
Recruit Iron- 0-99 posts
Recruit Bronze- 100-199 posts
Recruit Silver- 200-299 posts
Recruit Gold- 300-399 posts
Recruit Onyx- 400- 499 posts
EDIT:
try this
https://forums.halowaypoint.com/yaf_postst94930_Forum-Member-Ranks.aspx
Hey guys, this thread should answer your questions. My Forum Ranks thread showcases who has what ranking.