Also question is, is a juggernaut suit bulletproof?
Not in the way it is seen on CoD, no. The closest relative is the armor military uses for blast protection - EOD suit, I think the others called it. However it does not protect well against bullets and is not omnipotent against blasts either.
Subsequently, question is, how does juggernaut get his powers? In this show, Juggernaut is Professor Xavier's half-brother (rather than step-brother) and his powers are a result of a dormant mutant ability. This ability is awakened by the gem of Cyttorak. At some point, he has been caught and placed in stasis at a secure facility.
Thereof, what is a juggernaut suit?
The "Real Life" variant of a Juggernaut Suit is called the Explosive Ordinance Disposal (EOD) suit, more commonly known as the bomb suit. The Juggernaut Suit is supposed to turn the user into a small walking fortress, essentially. The armor is thick, big, and heavy, and limits the mobility and agility of the user.
Can a bomb suit stop a bullet?
The suit protects in several ways. It deflects or stops projectiles that may come from an exploded device. Until the mid-1990s, EOD suits consisted of Kevlar and/or armor plates to stop projectiles. However, the suits did not offer much protection against the blast wave itself.