I've gone every other year for the past 5 or 6 years, there has never been a weapons check. Honestly fear farm is pretty weak sauce man, its not bad if you haven't been to other BIG haunted experiences I use to just go to Fear Farm and then one year randomly me and all my friends decided we would hit every Haunted House in the greater Phoenix area, one of the best ones I went to was The Nest, and Fear Farm ended up being the worst that year. But you never know things change every year.
It was never out right bad when I was there, the set up is usually pretty good, but its the employees and the clientele that ruin it, Illegals run amok, as well as other "gang banger" types, you will be the only guy wearing a belt there that's a guarantee.
I haven't gone this year though so I can't give you an up to date review, I hope its good and it works out for you though. If you don't mind driving another 40 minutes you could always swing by The Nest.