Specifically designed and purpose built for AR15s and M16s with ambidextrous charging handles, the LDFA is a snag-free, rimless forward assist with a small footprint.
Both the LDFA and ABC/R designs are partially based on natural selection and mutation. As the AR and its manual of arms evolve, so should its controls. The oft-neglected FA evolved into the LDFA by becoming smaller, and rimless to accommodate ambi charging handles. The ABC/R went the other direction, with its larger, angled and easier to access paddles to accommodate ambi mag catches.
There has been ongoing discussions regarding the relevance of the forward assist. Like it and use it, or not, it is found on standard AR upper receivers. We don't want the forward assist to go away, we'd rather have it and not need it, than the other way around. LDFA does not have a rim on the plunger and is smaller than a standard forward assist. More importantly, on an AR15 or M16 equipped with an ambidextrous charging handle, when the user pulls on the right latch to load or reload the weapon, the rimless design allows for fluid rearward movement of his hand and charging handle, without snagging on his fingernail or knuckle.
The smaller footprint of the plunger face does not impact its usability.
CNC Billet construction, LDFA is machined from 4130 steel bar stock, heat treated with black nitride finish.
Proudly designed and made in the USA.
LDFA is designed and made to TDP specs and tolerances, and to work with TDP spec upper receivers. We've seen a troubling trend, where the lack of adherence to TDP specs and tolerances has created out of spec components, and receivers that are also out of spec to accommodate these parts, resulting in these receivers' inability to accept TDP spec components.
We've observed a few billet receivers with out of spec forward assist plunger hole diameter which causes LDFA, and TDP spec forward assists to have very tight fit. We've also noticed many forward assists, both "factory" with unknown origin, and aftermarket forward assists, have been significantly thinner in the plunger area. These receivers and FAs are out of spec.
Specifically, the FA housing's hole into which a forward assist is inserted has two diameters, the larger diameter hole for the plunger cap, the smaller hole for the plunger itself, These aforementioned billet receivers FA plunger holes are well short of the TDP specified diameter. LDFA's plunger measures 0.311, well within TDP tolerances. To date, we haven't seen any problems with forged upper receivers.
If you have a billet receiver, please measure the plunger hole in the FA housing. If it's less than 0.312 in diameter, LDFA will be a tight fit.
The rimless design of the LDFA means the user's knuckle or fingernail will not snag on the forward assist while he uses his right hand to pull back on the ambidextrous charging handle's right latch.
The picture below shows the path of a user's fingernail, and scratches made by it whilst pulling back on a Mega Slide Lock ambidextrous charging handle by its right latch. The scratches were not staged.
We have kept the factory forward assist plunger's concentric circular serrations. Various angles, contours, and serrations were considered, but we didn't deem any to be as versatile and accommodating (while some use the palm,, some may use the thumb to press the forward assist, and the angles of approach will vary) as the round forward assist's concentric circular serrations, first seen on the M16A2.