Ok bro... First of all you should describe the term "veteran". But I'll let that go and get back to the issue.
Generally I'm against squatting with any sort of equipment. I like the Ironmind style of No- No- No squats (no belt, no suit, no wraps).
But squatting with a belt helped me learn to push OUT my abs in order to improve stability. When you learn to push your abs OUT against the belt you'll not miss as many lifts.
So what I'm saying is the belt is a tool to be used... but the majority of the time you should lift without it and be on a steady regimen of torso training. Side deadlifts (suitcase dl's), side bends, roman chair situps, and anything that improves the stability of your spine.
I like 1 hand dumbbell overhead squats. but I'm weird as hell so take that with a grain of salt.
Though to be quite honest. If you can only squat 275 currently and your goal is to only be able to EVER squat 315... as in, after you reach 315, you'll rarely ever squat again.
Then you don't need this advice and I banish you to the land of yogurt pink vw beetles and hugh grant movies.
Strive for 4plates (405#), especially cause if you're around 150-200lbs... Regular squatting will probably put enough size on you to get you near to 200.
Thats a reasonable goal for any gym-goer, and not superhuman by any stretch of the imagination (unless you weigh 100lb's).
If you squat 2x a week...and only add 10lbs to your squat every month.
In 1 year, you've added 120lbs to your squat... Thats 395lbs. 10lbs away from 405.
And the truth is that you can probably do it faster than that if we were to take "newbie gains" into consideration.
You just need time under the bar bro.