Starting a gun club is relatively simple. The club can focus on a single activity or combine a group of activities for the members to enjoy. Consider whether your membership will be adult only, or if you will supervise youths in the safe handling of guns. Once you decide what your gun club will focus on, you will be ready to set it up.
Attend a few meetings at other gun clubs. You can see how they are set up, any special rules or considerations you may need to look into, and decide whether this will be a business that you should incorporate or possibly set up for tax registration purposes.
Organise your club by electing officers, deciding on rules, where and when to meet, and what the proposed activities will be. One consideration is if you are planning on actually shooting the firearms as opposed to just collecting the firearms. If you will be shooting, you need to find out if this requires liability insurance. You may want to set up a shooting range and will need insurance, as well as special permits from your local planning and zoning committee.
Focus on safety and training in handling firearms, even if you are just planning a collectors' club. If two or three people have special certification from programs such as the National Rifle Association, you have something to offer your members and to use to recruit new members.
Your Second Amendment gives you the right to enjoy firearms. Uphold the constitution in your bylaws and rules with safety and education.
Check local zoning laws that may prohibit firing of weapons in populated areas.