Words and Pics: Rich Norman

I’m waiting for a few bits and pieces at the moment, but the L119A2 will never be an overnight build.

Like the previous replicas that I’ve put together with any degree of authenticity (a Block II M4A1 and an AFSOC M4A1), it is going to take quite a bit of time to get right.

But that won’t stop me using it prior to completion, as it’s a wieldy beast. From handling the IUR as part of a complete carbine, I can see why the Magpul AFG2 appears to be so widely used in the wild; and how it would complement the IUR’s handling.

As for the upper per se, HAO has sent two additional extras which I hope will arrive in the next week or so. Those items feature in the production version of the IUR: a heat shield (which I gather is fiddly to fit) and a replaceable ‘notch’ which retains the charging handle latch.

I’m also waiting for a 32mm crow’s foot wrench. This will allow me to torque the IUR’s barrel nut, by connecting my 1/2″ drive torque wrench to the flats on HAO’s barrel nut tool.

All that being said, I have been able to test fit the IUR with my existing Prime M4A1 Colt lower as alluded to earlier.

I did this just to see how the combination fits and it’s impressively rock solid. In fact, I’d be surprised if HAO’s forthcoming L119A2 lower would deliver a more precise fit.

I was impressed at how light the IUR is and how well it handles; especially when compared with my HAO HK416A5 – a contemporary platform, which feels very heavy and pretty ungainly next to the IUR.

That’s not surprising given the design of the IUR, but it wasn’t until I used the upper as part of a whole that the benefits became palpable.

While the semi-slick front end does trim weight, that’s not even half the story. The rail/receiver monolithic form factor is fundamental to the IUR’s low weight (not to mention much stronger than a traditional design); but equally the IUR does not have a hulking great gas block, hefty A-frame sight, or massive barrel nut.

The gun drilled steel barrel is – as is usual with PTWs – the heaviest component, but the tipping point is still further to the rear than I had anticipated. This will of course change with an FH556-216a replica in situ.

Back to putting things together and the upper to lower fit wasn’t quite plug and play. I first had to remove the leaf spring which HAO has decided to add to the IUR’s rear takedown pin lug.

The leaf spring isn’t something native to the IUR, but something HAO picked up while studying the HK416A5.

While it is easily removed if required, it’s been included so that the upper can be customised to a wider range of lowers. It basically acts like an Accurizing Wedge, preventing play between the upper and lower receivers. I can imagine it will be useful for those seeking to fit HAO’s IUR to DTW and other off spec lowers; even Systema’s own recovers can be a bit wide of the mark. No one likes slop – it’s ugly.

I used a small screwdriver to ease off the device and bagged it just in case I need to refer to it in future. It can easily be bent back into shape and replaced should the need arise. However, Tackleberry has informed me that he will be removing the leaf spring from all HAO IURs which pass through his hands, as he sees it as unnecessary.

Because I’m not permanently mating the IUR with my Prime lower, I needed the two items to fit together without further modification. They did just that.

A more permanent solution would require light reaming with a file in the rear takedown area, but that wasn’t necessary for the test fit.

And remember: this is my AFSOC lower which is why it’s dressed inconsistently to the upper.

The last thing I wanted to make sure of was that the IUR’s picatinny was on spec – and it is. To do this I added what I had to hand – not optics I will use for the final build.

In fact, not only is the picatinny on spec but the EOTech EXPS and G33 from my HK416A5 dropped right in – with absolutely no adjustment required. This shows how consistently engineered HAO products are. I have never transferred optics between builds before without some adjustment.

The other thing this exercise confirmed is that deviation from what’s seen in the wild is absolute heresy with the L119A2.

I was actually in two minds about publishing these pics, but for evaluation purposes I think readers will understand. Furthermore, this gives me a solid reference point to refer back to as the build progresses.

Catch up on the full HAO IUR series here.

For more on the L119A2, check this out.

Also check out my interview with UKSF impression group E27 here.