EP9 Rifle-Length Upper Installation

WARNING: Before starting, ensure that your firearm is unloaded and that the area is clear of all ammunition.

Field strip your pistol by removing the upper from the lower, then set the lower aside.
Pull the charging handle back until the bolt is protruding, then remove the bolt and set it aside.
Pull the charging handle all the way to the end of its track in the upper, then pull it out.
Using the end of the charging handle, push on the charging handle slider block through the track in the upper until the block is protruding from the upper.
Remove the charging handle slider block and set it aside.
For EP9s with a Blast Director muzzle device: Unscrew the blast director from the muzzle and set it aside, then take off and set aside the split lock nut.
Using a Phillips head screwdriver, unscrew the two handguard screws and then pull the handguard off.
Set aside your pistol upper.

Take your handguard and rifle-length upper.
Put the handguard on over the barrel and mount it up to the barrel nut, taking care to ensure that the front hook on the picatinny style rail properly lines up with the handguard.
Using a Phillips head screwdriver, install the two handguard screws and hand-tighten them. (DO NOT USE POWER TOOLS FOR THIS STEP)
With the angled corner pointing towards the upper, install the charging handle slider block and push it forward until the hole for the handle is in the center of the open portion. (reference photo)
Insert the charging handle and move the handle forward.
Insert the bolt all the way into the upper.
Put the upper on the lower and push in the takedown pin.
Function check that the bolt is cycling properly and that the trigger functions and you are all set!

EP9 Rifle-Length Upper InstallationUpdated a year ago