RifleGear - Installing a Two-Piece Forearm

The standard handguard system on an AR-15 consist of two polymer plastic halves which are are held in place under spring-tension. Each end of the handguard halves contain tabs that are inserted into an end-cap on the end near the front-sight base, and the cone-shaped delta ring (or slip ring) found closest to the upper receiver. Between the upper receiver and the delta ring is a weld spring, which provides the spring tension.

Replacing the handguards is a trivial task if you have an assistant or if you happen to own one of the "Handguard Removel Tools" available for under $15.00. In this installation guide I demonstrate how to replace the standard handguards by yourself, but if you can get someone to help you it is a lot easier and can be done in just a minute or two.

	In this case I am replacing the full-length handguards on a Stag Arms Model 4H upper with the Midwest Industries Full Length Forearm, model number MCTAR-19, although the process is the same for any length handguard and from other similar two-piece handguards from other manufacturers.
	If the upper-half is separated from the lower-half, then use a towel or other material to protect the upper from scraches and brace the upper in a vertical position and grasp the delta ring with both hands. You do not need to remove the upper half and it is quite easy to do this just seated in a chair with the stock of the barrel in your lap. Squeeze the delta ring between your thumb and index fingers and pull down as far as you can to compress the weld spring.
	It's a little tricky, but once the delta ring has cleard the tabs on the end of the handguard halves use your thumbs to seperate the handguard halves in opposite directions until they clear the delta ring. This is where that assistant comes in real handy as they can just pull the halves apart as you compress the weld spring. If working alone you may find it easier to just concentrate on sliding one half over just enough to hold the delta ring in the compressed state so that you can then use both hands to remove the handguards. Once the handguards have cleared the delta ring just pull them down to remove them from the end-cap and off of the upper assembly.
	We are half way there now.
	Unlike the standard plastic handguards, each half of the Midwest Industries two-peice forearms is not identical as there is clearly a top half and a bottom half. The top half contains three rails while the bottom half contains only one. Insert the tab ends of both halves into the end-cap taking care to ensure that the T-marks are ascending in the correct sequence (i.e. that they are not backwards).
	Now set the rifle back up in a vertical position, grasp the delta ring again and push down to compress the weld spring. Take care to also hold the forearm halves in position so that they do not fall out of the end-cap. If you have an assistant, have them push the forearm halves together towards the barrel. If working on your own, just try to get them in place while you also keep the spring compressed. It is tricky but with a little work you can get it done. You may find it helpful to hold a pencil or plastic pen between your teeth to push one of the halves into place as your finger strength may be starting to wane at this point.
	Check the delta ring to make sure the tabs from the forearms are completely in place and that the forearm is straight and secure. Pull on the delta ring a bit to make sure the weld spring is pushing it fully into place.
	You are finished! Time to mount some rail panels or other accessories on your new railed forearm.