  In this study we explore the LHC's Run II potential to the discovery of heavy
Majorana neutrinos, with luminosities between $30$ and $3000$ fb$^{-1}$ in the
$l^{\pm}l^{\pm}j~j$ final state. Given that there exist many models for
neutrino mass generation, even within the Type I seesaw framework, we use a
simplified model approach and study two simple extensions to the Standard
Model, one with a single heavy Majorana neutrino, singlet under the Standard
Model gauge group, and a limiting case of the left-right symmetric model. We
then extend the analysis to a future hadron collider running at $100$ TeV
center of mass energies. This extrapolation in energy allows us to study the
relative importance of the resonant production versus gauge boson fusion
processes in the study of Majorana neutrinos at hadron colliders. We analyze
and propose different search strategies designed to maximize the discovery
potential in either the resonant production or the gauge boson fusion modes.
