Blue Trail is your best bet. It is open every day. Weekdays are best because the day passes are reasonable (on weekends the hourly pass costs as much as the weekday day pass). Zeroing a rifle at Blue Trail is a pain the rear if you are doing more than confirming / adjusting your zero at 100 yards. You have to wait on a cease fire every half hour to go down to your targets. I also don't think you can shoot 25 and 100 / 200 yeard targets from the same position.

I suggest you break down and join a club.