Smaller then their Framing Nailer counterparts Brad and Finish nail guns are used mostly by Finish Carpenters to install Moldings, Cabinets, Interior Doors and Build Decks.
The size and amount of fasteners that you need to use will dictate whether you choose electric or pneumatic guns. Air Nailer are great when you know you need to use either a larger nail or a lot of nails in a short period of time. Electric or Gas Charge Nailers are good for lighter duty work or when you are working on a remodeling project where the home owner is living in the house.
Fastener sizes range from about a half inch to two and a half inches. The nail types are also available in a variety of forms and some like a T head nail are specialized just for finish nail guns. Some guns can double as a Staple and Finish Nail Gun. This is good for general contractors as the need to carry many different types of guns is less.
Some features you should look for.
What is the air or electric needs of the gun. Larger fasteners need more power. As a general rule a 2.5hp compressor should be able to run Two finish nail guns for light carpentry. Larger electric Staple / Nail guns will require a decent amount of amperage so you should always use a heavy grade 12ga or better extension cord.
Rubber Feet
If you will be working on finished materials like cabinetry you should always use a rubber foot on the gun to reduce the possibility of marring the surface. Even when you are working with materials that will eventually be stained and not painted it is best to use a rubber foot so you can reduce the amount of filler needed to hide the nail head.
Gas Charge Nail Guns
Gas charge guns are run from a combination of battery and a small gas canister that fuels the piston of the gun. Every time a nail is shot a small amount of gas is shot into the piston cylinder then it is ignited by the battery. It is important to keep backups of both the battery and gas charges when you are working in the field but because the gun is self contained there is no need for air compressors or extension cords.
Battery Only Nail Guns
A new type of gun is starting to hit the market Battery only Finish Nail guns are able to drive about 500 2 inch and smaller finish nails on a single 18 volt battery charge. Basically this is an electric fastener gun that has been modified to run on a cordless tool battery. If you are interested in this type of gun checkout Black & Decker and Dewalt.
Warranty
Contractors should be careful to read the warranty information for their tool. Some manufacturers restrict warranty coverage if the tool is used by contractors. It is not unusual to see tools that are primarily used only by professionals advertised with 3 or 5 year or even limited Lifetime warranty but if you check closer you might find that only home use is covered for this extended period and if the tool is used for business then the warranty is only 1 year.
Check the facts before you buy your tool and check if your tool can be serviced locally or if you must mail it to the manufacture.