EPC (Ejection Port Cover) is based on TDP dimensions, with
thoughtful Forward Control touches. Billet machined from 7075 aluminum,
and hard coat Type III anodized, it incorporates features we think many
will find useful.
EPC has two "tabs" flanking
the cutout for the port cover spring. These tabs allow the EPC to rest
on the upper at a greater angle when it's in the down/open position,
which provides more space between the port cover and lower receiver.
Their job is to better allow the user's finger to get underneath the
port cover when they wish to swing it up/close.
Left: TDP ejection port cover. Right: EPC. Both in the down/open position. Please
note that depending on the upper receiver, the area below the ejection
port cover will vary in thickness, which affects the angle of the EPC
when the port cover is open/down.
Another feature is a shallow circular depression on the side of the
EPC to provide texture tactile feedback to the user's finger when he's
closing the EPC. A flat surface provides nothing to the user to
differentiate one surface from another, it also provides no traction. A
shallow circular depression on the left side of the EPC does both. We
incorporate flat surfaces with care as they have their uses. In this
case, EPC's exterior surface is treated as a control surface, where a
flat surface rarely makes sense.
EPC is compatible with TDP spec upper receivers.
Proudly designed and made in the USA.
Includes a TDP spec spring, C-Clip, and rod for assembly
EPC is incompatible with BCM's Mk2, Aero M4E1 and Centurion Arms CM4 upper receivers.
Initial closing and opening of EPC may be stiff, this is normal, and will become easier with 2 or 3 closing/opening cycles.
examine the upper's ejection port cover latch/detent relief cut. If
the ejection port port latch/detent relief cut is cut too shallow,
slight modification may be required for EPC to close.
picture shows two upper receivers. The difference of the relief cut is
visibly different. On the TDP spec Colt, the shape of the cut is
beveled. On the no name upper, the edge has a 90 degree angle. ECP
will fail to close on the upper on the right without slightly relieving