Normally, the barrel rests in contact with the stock of a rifle. Environmental conditions or operational use may shift alignment of the stock, which may cause the barrel to shift its alignment slightly over time as well, altering the projectile flightpath and impact point. Contact between the barrel and the stock also interferes with the harmonics of the barrel, which can have a detrimental effect on accuracy. Luckily, free floating a barrel can help alleviate these symptoms and bring greater accuracy to your rifle. I have broken down the process of free floating an AR-15 down into a few basic steps with pictures to help anybody modify their rifle easily without a gunsmith.
Step 1: Tools
You need the proper tools. Using an incorrect tool on a rifle can cause severe issues in the future. For this job you will need a Roll Pin Punch set, a set of Allen Wrenches, and a Phillips Head Screw Driver.
Step 2: Required Parts
You will need a free float kit, I will be using a Vltor Casv-M for this example for simplicity. You will also need a Low Profile Gas Block, this is so the hand guard can cover over the block with clearance.
Step 3: Dissembling Your Rifle
Remove the two main take down pins of your AR to separate the upper and lower receivers and pull back on the charging handle to remove the bolt carrier group. Now that you have your upper separate you can remove the original hand guards. To do this push down on the delta ring firmly and pry the hand guard free. You can use a small screwdriver to separate the hand guard's halves to make it easier.
Your rifle should now look something close to this.
Step 4: Gas System Modification
We now need to remove the gas block to replace it with our new low profile block. Gas blocks come in many different variations but most use roll pins, clamps, or a set screw to hold the block in place. Just simply remove the device attaching it to the barrel and the block and tube should slide freely off the barrel together. In this example the gas block is set screwed to the barrel and a roll pin attaches the tube to the block.
Knock the roll pin holding the gas tube onto the block and separate the two.
Now line the gas tube holes up with the holes on the gas block and make sure the tube can breathe and isn't obstructed. The more you get it lined up the better.
Now reassemble the gas system and make sure the tube goes into the upper completely. Line up the tube so it is straight as possible and reattach it to the barrel of the rifle.
Step 5: Free Float Guard Installation
The Vltor Casv is very simple to install. It piggybacks on the top rail of the rifle it is attached to. Just slide it over the barrel with the bolts of the Casv's rail loosened. Tighten the rail down onto the top rail of the rifle and free floating is complete. Your AR is now optics ready and free floated.
FIN!
