Okay, hi guys, i think this is my first post on a Halo forum, so go easy on me. Now, to my knowledge, there is nothing unlockable or gainable at any level higher than 50. With that said, is there any reason to bring our service ranks any higher than that?
I thought they go much higher than 50
Once you get past SR 50 you unlock new specializations which means you can unlock new ‘perks’
You mean the 8 Specializations?
Each time you complete a specialization (moving up another 10 ranks), you receive new and specialization exclusive armor sets, skins, and emblems. That would be 8 new armor sets and emblems for finishing the specializations (rank 130). At the end you get a bonus too, thouh I don’t know what that was. Perhaps more emblems or stuff.
Whoops, forgot that you unlock more Modifications too. with each soecialization.
When you get to 50 you don’t rank up until you choose a specialization, when you pick one it advances you to 51 and changes your title to whatever specialization you chose.
As you level up you unlock armour pieces, emblems, weapon skin and at 60 you get a new Support upgrade, then you’ll have to pick a different one at 60 and so on, and so on.
Other than the specializations, you get nothing after 50. But you should get way higher than that anyways. Its like reaching inheritor and still playing Reach. Play the game because you enjoy it, not to unlock everything 
Whoah, okay, I didn’t realize the specializations give that much stuff other than their respective perks/skills. Thanks so much guys!