Whether you are a do it your self er or in the construction field the Hitachi nail gun is the only way to go for your project.

The Best nail guns are Hitachi and my favorite is the Hitachi NR 83A2:

The Hitachi NR83A2 shoots 2" to 3 1/4" nails.  It weighs roughly 7.9 lbs and seems to be perfectly balanced.  It also has a built in depth adjuster so you do not over drive your nails.   The Hitachi NR83A2 is equipped with a selective actuation switch. This allows you to use the nailer in either sequential or bump firing mode. The sequential mode is useful when you need more accurate fire. In bump firing mode, the Hitachi NR83A2 is useful when speed is more important than accuracy.    It also features a rubber grip for comfort and has an open nose to easily clear jams.

Now that you think I am a salesman I will tell you my experience with this gun:

I have been in construction since I was 15 yrs old and I am 28 now.  I have built just about everything you could imagine and I have used every nail gun out there.  The Hitachi NR83A2 out works them all.  They are powerful enough to drive a 16d hot dipped galvanized nail and delicate enough to put on finished trim board when siding, thanks to the depth adjuster. They are durable, I have dropped the Hitachi off a 3 story building onto a concrete garage slab, the gun was fine but the 4 day old slab didn't fair to well.  I cannot tell you how many times I have dropped this gun and the only part that has been broke is the nail rack.   The nail rack although is easily replaceable.  You literally have to take out 3 bolts.  You can also use the back of the gun as a small sledge hammer to beat things around.  This is the fastest shooting gun I have used,  about 3 nails per second without jamming.  (Even faster if you take out the springs, which I do not recommend).  This gun is used by most carpenter union workers, and this is the only gun I have ever seen in the field on residential framing.  I'm sure others are used but I have not personally seen one.

It doesn't stop there.  The Hitachi NR83A2 can attach fasteners such as deck hangers, hurricane clips, seismic straps and many others.  They have created a teko nail that shoots from the Hitachi.  You used to have to buy a separate gun for straps and clips.  This saves valuable time and money since hand nailing them takes a while and buying a teko nailer is expensive.

The Hitachi Nail gun is also great for keeping around your house for projects.  My wife who is 5'4" 115 lbs. loves the gun.  You will never have to worry about hand nailing anything, especially the divets you get from your hammer.  These are very safe to use.  Just make sure to wear eye protection because of the popcorn (that's what I call the plastic from the nail strips).  When you are doing finish work make sure to test the depth setting before shooting the nail into the final product.

Maintenance:  This gun requires very little maintenance.  Before using your gun just squirt a few (between 3&10) drops of air tool oil (really any light oil)  into the air fitting on the bottom. If you are using your nail gun all day, you should add oil a few times throughout the day.  Another great tip is to get a filtered air fitting to keep dirt, dust and debris out of the piston chamber (be sure to use Teflon tape around your air fittings).  Also spray your rack with a lubrication and all other moving parts.  Make sure to tighten all screws and bolts at least monthly.

In essence the Hitachi NR83A2 is, in my opinion, the best framing nail gun out there.  I know this from my vast experience in the construction field.  They are extremely durable, comfortable and fast.  Keep them clean and oil daily and this tool will last a lifetime.

Specs

• -Model-      NR83A2
• -Fastener type-    Full round head, plastic strip
• -Depth Adjustment-  Yes
• -Magazine angle-  21 Degrees
• -Fastener diameter range-  .113" to .131"
• -Magazine Capacity -  60-70 nails
• -Magazine Loading -  Top
• -Air Inlet- 3/8 NPT Thread
• -Operating Pressure- 70-120 PSI
• -Air Consumption- .088  FT3/cycles at 100 psi
• -Jam Clearing-  Open Nose
• -Actuation- Selective (sequential/bump)
• -Length-   21 13/16"
• -Width- 4 1/4"
• -Height- 13 3/8" 
• -Weight 7.9 Lbs

1. Hitachi Pneumatic Framing Nailer with Depth Adjustment - Full Round Head - 3 1/4" - Plastic Strip Collation - NR83A2
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3. Hitachi Pneumatic Framing Nailer with Depth Adjustment - Offset Round Head - 3 1/2" - Wire Weld Collation - NR90AF
4. Hitachi Pneumatic Framing Nailer with Depth Adjustment - Full Round Head - 3 1/2" - Inspire Design - Plastic Strip Collation - NR90AE
5. Hitachi Pneumatic Framing Nailer- Full Round Head - 3 1/2" - Plastic Strip Collation - NR83!