Umarex x H&K 416 A5 Mod1 Airsoft AEG Rifle w/ C.A.T. Split Gearbox and ARC FE ETU - Arcturus

"★★★★★ Great Rifle, Terrible Documentation

I’ve owned a lot of AEGs over the years, and the Elite Force HK416A5 MOD1 by Arcturus is one of the best-performing rifles I’ve used straight out of the box.

Performance is excellent. Trigger response is fast, accuracy is great, and the ARC FE ETU offers a lot of programmable features. The split gearbox design makes spring changes easy, and the rifle feels extremely solid overall. The externals are well-made and the gun has been reliable for me.

My biggest complaint isn’t the rifle itself, it’s the documentation.

The stock battery compartment design is frustrating. The battery door is retained by a pin, so you can’t simply pop the door open like most stocks. To access the battery, you either have to remove the retaining pin or remove the stock from the buffer tube entirely. It’s not difficult once you know how it works, but it’s much slower than it should be and isn’t explained particularly well. I also found battery space to be extremely limited, to the point that I couldn’t comfortably use the three shortest stock positions with my preferred batteries. I ultimately replaced the stock with a PTS EPS2, which provided more battery space and allowed me to achieve the length of pull I wanted.

The other issue is the gearbox. If pre-cocking is enabled, the gearbox can remain under spring tension and may refuse to split apart. Neither the rifle manual nor the ETU manual explains how to release the spring tension. I contacted Arcturus directly and still couldn’t get a clear answer.

After figuring it out myself, here is the procedure:

1. Enter ETU programming mode and disable Pre-Cocking.
2. Exit programming mode.
3. Set the rifle to Semi-Auto.
4. Fire one shot.
5. Release the trigger, then pull and HOLD it again.
6. After about 10–12 seconds, the rifle will beep 3 times and you’ll hear the gears move slightly.
7. Release the trigger.
8. Pull the trigger again and continue firing until the rifle stops firing and emits one long beep. Mine takes 3 shots.
9. The spring tension is now released and the gearbox can be separated by removing the rear takedown pin.

This information should absolutely be in the manual but currently isn’t.

Despite those complaints, the rifle itself is fantastic. Excellent performance, great trigger response, solid construction, and lots of features for the money. If Elite Force and Arcturus improved the documentation, this would easily be a near-perfect package.

The only internal modification I’ve made is installing a 4UAD Quantum bucking, which has performed very well.

Would I buy it again? Absolutely.