I would call the 3 or 4 most popular and largest ranges near you and find out if they host weekly or monthly shooting competitions (IDPA, Steel Match, etc.,) and get the POCs for the shoots. It’s probably on their websites...
Then, simply contact them and ask if they’d be interested in sending out an email on your behalf to their shooters.
I am not saying to “give it away”, but if you make your prices attractive, you’ll get buyers.
Just last weekend, our IDPA host sent out an email to us about someone selling a bunch (4-5K) of mix and match commercial 9, 223, and .45. I text the seller later that day and it was all sold (to the same guy). He told me could have sold 20K easy. His prices were about 75% of local Academy prices.
Key is get your list together and send it out to a mailing group of shooters...