I’ve already blogged about the first instalment in HAO’s Economy Line – its $100 Geissele MK16 SMR replica.

The company has now strongly indicated that it intends to release a widely compatible rail-only version of the UKSF L119A2 IUR.

For those unfamiliar with the IUR (Integrated Upper Receiver), where have you been? The L119A2 – of which the IUR is a part – is well on track to be the coolest gun of 2019. Yeah – it was cool already, but less well known outside the UKSF impression scene.

It went global in early January.

In the real steel, the rail portion and upper receiver of the IUR are forged into one continuous unit – what LMT (the patent holder for this type of structure) calls a Monolithic Rail Platform.


As you may imagine, bringing a truly monolithic IUR to market is an expensive undertaking. To date, only HAO has produced one and they did it to send a message – not to shift units. It arrived in August 2018 and sold out immediately, much to their surprise. A revised batch will be available in Q2 2019.

However, as opposed to a monolithic structure, there is an economical and pragmatic workaround which has been adopted by most L119A2 builders. Angry Gun makes a substitute product in the form of a non-monolithic, stand-alone rail. It was released in Europe in October 2017, then worldwide in January 2018.

Angry Gun got the idea following advice and information from a couple of guys well known in the UKSF impression scene, where some L119A2 builders had already started using substitute rails to make ‘squint test’ IUR replicas. Angry Gun formalised this practice.

When added to a generic Colt M4 upper, their rail mimics an IUR front end. Squint and it could be monolithic; particularly if you go all the way with the Miliput mod.

Balancing value with the squint test, Angry Gun’s rail is incredibly popular. It’s compatible with a wide range of airsoft platforms – making it extremely versatile.


On the other hand, HAO’s monolithic IUR replica is – naturally – platform-specific; and it is currently only available for Systema PTW. That’s the segment HAO’s products are overwhelmingly aimed at. It’s a market where – in HAO’s opinion – there’s a greater appetite for the expense of a truly monolithic IUR. The PTW also has very high RS parts compatibility and, of course, one of HAO’s selling points is that it makes 1:1 replicas.

However, the company has now turned its attention to a much simpler proposition: an economical and pragmatic IUR rail in the style of Angry Gun.

Standing well clear of the rail form factor while developing their monolithic IUR replica, HAO has created the opportunity to do exactly what they did with their $100 MK16 rail: survey the field then ask the question, “Can we put our spin on this product?”

HAO claims that their MK16 SMR has improved upon the existing market leader’s offering, while undercutting its circa $150 price tag by a considerable proportion.

Needless to say, healthy competition is great for the market – so it’s the consumer who benefits.


I asked Bismarck – HAO’s CEO – what motivated the IUR rail decision.

His answer was this:

We do it, because we can.

HAO’s L119A2 monolithic IUR for Systema PTW was the fastest selling HAO receiver ever. We can now broaden our appeal by building on that success.

We already have real steel data to leverage and knowledge from manufacturing our monolithic IUR, which will differentiate HAO’s IUR rail.

And the price will be very competitive.

Our IUR rail is a way of making HAO’s brand more accessible and ubiquitous – to fit a wide range of platforms, including the Tokyo Marui NGRS and – crucial to our long term strategy – the GBLS DAS.


The rail will, of course, also be available with a PTW/RS thread barrel nut – for those who don’t wish to push the boat out as far as a monolithic upper. There will also be other PTW L119A2 Economy Line items in the series, but I can’t say anything about those just yet.

I’m told the new rail won’t offset current plans either, as it’s a relatively straightforward project compared with HAO’s usual output.

The full L119A2 kit for PTW – including the revised monolithic IUR – is imminent (Q2 2019); then there’s the production version of HAO’s CAG 416D for PTW.

A HAO receiver set for Tokyo Marui MWS is also in the programme for 2019.


Catch up on the full HAO IUR series here.

More articles relating to the L119A2:

  • The original L119A2 primer, here
  • GG&G AR15 vertical fore-grip in use here
  • Magpul QDM and ASAP QD in use here
  • 15.7″ L119A2 upper in use here
  • Surefire FA556SA Suppressor here
  • GG&G Aimpoint T1 mount in use here
  • Magpul MS3 sling in use here
  • Magpul ACS stock in use here
  • Colt Canada parts – as used on the L119A2 – here
  • Manta Very Low Profile Rail Covers as used on the L119A2 here
  • UKSF Newcastle raid pics part 1
  • UKSF Newcastle raid pics part 2
  • UKSF Nairobi Kenya incident L119A2 parts breakdown here
  • UKSF Belize ‘Jungle Set-up’ L119A2 parts breakdown here
  • Confirmation bias (and the HSP Thorntail offset light mount) here
  • UKSF Ecosystem: S&S Precision Sling Clip – Old Gen – here
  • Inforce WML-type lights in use here

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Obi Wan Nairobi patch from Platatac