NOTE: REF is a standard carbine receiver extension, it is not compatible with the Vltor A5.
REF (Receiver Extension, carbine, FCD) is a 6 position, AR15/M4 standard carbine receiver extension (NOT A5 compatible). Made from extruded 7075 aluminum with rolled threads and dry film lubed interior, REF differs from most carbine receiver extensions thusly:
* Additional drain holes in the 2nd and 5th latch positions, in addition to the TDP spec carbine RE drain hole at the end of the RE.
* Laser engraved stock latch position indicators on both sides.
We’re not known for making modifications to TDP spec components just to be different. Different is just that, different isn’t better. REF follows our design philosophy, function over form, form follows function. The changes on REF are for the most part not immediately visible to users.
Colt M4 stocks have an open portion on top the butt pad, TDP spec carbine RE has a drain hole at the end/tip to allow water to drain. The M4 stock can trace its origin to the early 1980s ACR trials, though they ended without any being adopted to replace the M16, inevitably some developments led to designs later incorporated into production systems, one of which is the now ubiquitous M4 stocks made by Colt, and later, SOPMOD stocks made by Crane at NSWC, LMT and B5 Systems. Stocks with superior cheek weld and storage made by industry giants Vltor and Magpul have long led the way in ergonomics and practicality.
Often, these much improved stocks have integrated butt pads that close the open end of the M4 stock. REF retains the drain hole at the tip of the TDP spec carbine RE, but also adds two more under the stock, in the 2nd and 5th latch positions. OTB feature may not be something a casual, recreational shooter demands, it is our practice to incorporate combat weapon features in our designs.
The side stock latch position indicators (on both sides) is a twist of a feature we have long admired from one of our favorite companies, Vltor. Vltor has been engraving stock latch position numbers on top of its carbine REs. For M4 and SOPMOD stocks, there is a hole on top, it is necessary for the lock release lever’s spring loaded pin installation. Vltor has made use of it and engraved position indicator numbers below the hole, in typical Vltor brilliance.
REF’s stock latch position indicators are located at 3 and 9 o’clock, because many of the popular and superbly designed Magpul stocks don’t use the lock release lever found on the Colt M4 stocks and SOPMOD stocks, they therefore lack the release lever pin hole on top of the stock body, numbers engraved on top are visible to the users, but they no longer correspond to the actual positions. By relocating the numbers on both sides, users can easily and quickly identify the latch positions of their stocks.
Carbine RE latch position grew from 2 (either completely closed or open in early Colts carbines) to 4, it’s common to find 5 or 6 positions on standard carbine REs (our RE5F, the Vltor A5 compatible RE has 9). While the increase in latch positions/adjustments offers the users better ergonomics, it does make identifying the position of the stock by tactile feedback somewhat more challenging. We would prefer if we don’t have to look at the weapon while deploying it. That said, if and when time allows, the correct and consistent length of pull is rather helpful.
REFs features aren’t new individually, REF is simply a carbine RE done our way. The 2 extra drain holes are enough to facilitate rapid draining of water from the RE, it doesn’t need 6. The side stock position markings are small and discreet, large enough to be visible, but not call attention to themselves. Fashion has no place on duty/defense firearms.
Proudly made in the USA.