Guys like that are sorta' like the bullies at the beach, and elsewhere. The best thing to do is simply ignore them.
Don't give any credence to anything that they have to say.
If they get pushy, walk away.
If they get physical, make sure that they never want to get physical with you again.
I learned the hard way too many times in my 20s that even talking with these jerks is a waste of my time. At the ripe old age of 66, I just can't be bothered with that crap. Simply can not be bothered. I wouldn't have given him the satisfaction of even answering him.
As long as you can shoot well enough to do what you have to do in an emergency situation, that's what counts, and is the only thing that counts.
Good Luck on your match. I hope you do blow him away. But, if not, don't sweat the small stuff.
Take Care, God Bless, and WATCH Your Back!