...New Mexico Statute 30-7-2.2 states you must be at least 19 years of age to possess a handgun...
So an 18-year old (legal adult) can only carry a long gun?
Haven't we allowed an exception to the long gun carry
discussion rules when that is the person's (state's) ONLY option to exercise their RIGHT to bear arms?
I absolutely agree that long gun open carry is not preferred. And I absolutely agree that it should be off topic for "open carry."
But are we basically telling this legal adult to go away and come back when he's a year older?
If it is his only option, I (an admitted absolute nobody around here) am okay with discussing how to do it in the least scary way possible while putting the emphasis on changing the laws to allow all adults to carry sidearms.
So, my best advice to the OP is to contact your state legislators. You are an adult, and are being forced by state laws to carry a long gun if you wish to be armed in society, which is your right. If state legislators believed for one second that 18-year-old adults were actually going to exercise their right to be armed, I promise you they will very quickly change the law to allow that arm to be a properly-holstered handgun. Similarly, in states where you must be 21 to get a concealed weapons permit, if there were a significant number of armed 18-20-year-olds, the law would quickly change to allow them to carry concealed, but the fact is most people would rather be disarmed than OC. Sad.
Research the various police departments in the state. Are there any that allow 18-year-old employees? If so, can any of them carry sidearms? Do the same with security companies. The information can be of use, regardless of the answer.