Whilst I’m not really a fan of speedsoft, I really quite fancied a gun with a higher ROF (even if it’s just for show as I would never actually want to hurt someone by firing a bazillion rounds of BB’s at them – that’s just dickish!) but the lowly ~15 RPS from my G36 wasn’t scratching that itch so I decided to treat myself to an ARP-556 as it was getting a lot of praise from reviewers at the time!

No sooner had the ARP landed with me, it was shipped off to Miguel (now part of CamoCustom) for a raft of upgrades including a BTC Spectre mosfet, rhopped EDGI TBB barrel, Maxx tracer hopup unit, purply prommy bucking, higher speed motor, FPS tune to ~340FPS on 0.2g’s and a general service.

After a few weeks wait, it came back an absolute monster albeit with a couple of caveats – the rather tightly packaged handgrip got VERY warm after a little semi usage (despite the gun only running modestly quicker than before at approx 26 RPS on an 11.1V LiPo!) and it would drain the small buffer tube batteries too quickly for my liking!

Upgrades ARP 556 with Vortex SPARC sight, Opemen Fast301 light & SOCOM style stock

After discussions with a different tech, this time Sam @ Kingdom of Airsoft, a plan to resolve both of my issues had been formed (hot motor, fast draining battery & general lack of battery space due) and this was to;

  • Switch from an SSG build with very high speed motor to DSG with a slower motor – I wasn’t in search of the ‘fastest speed’ so it would be possible to get a more efficient, DSG that put less strain on the gun internals
  • Retro fit UV LED’s into the Maxx tracer hop up unit in place of the ultra bright, high energy drawing white LED’s that were installed
  • Replace the beautiful yet heavy SOCOM stock with limited battery space for a PTS EPS stock and switch to a larger, higher discharge LiPo.

Progress of this plan was slow and tedious as the ARP came back to me along with notable tech time bills a number of times and yet it had to keep going back under to warranty due to significant issues cropping up (bearings smashing, gears failing, inconsistent FPS etc) and all this back and forth and dissasembly had also taken a toll on the ARP’s bodywork which was now scuffed – something I was less than pleased about!

After lots of head scratching, it was discovered that the upgraded Siegetek gears once shimmed were not sitting perfectly within the G&G gearbox which was causing abnormal load on the bearings until they failed – prematurely. Additionally the vast amount of recoil the gun now had was causing the barrel to move within the Maxx hopup unit which, in turn, was causing the FPS inconsistencies.

The proposed solution was to upgrade to a Retro Arms CNC shell and Retro Arms hopup unit with barrel fixing collar however the hopup unit had no tracer option. As the ARP would be on the bench, I decided I would ‘kill two birds with one stone’ and switch out the damaged ARP body for some awesome looking parts I had found overseas at the same time!

Custom build DSG with G&P parts machined to fit

For once, everything seemed to finally come together as a few weeks later I finally had what seemed to be a working and reliable DSG however, this wasn’t the end of the journey just yet as whilst the Retro Arms hopup unit resolved the FPS fluctuations, the lack of integrated tracer was something I sorely missed.

Not wanting to touch the externals by fitting a mock suppressor with integrated tracer (as the gun looked perfect and perfection is not to be messed with!) I enlisted the help of Futuretech Airsoft who agreed to attempt to machine my Retro Arms hopup unit in order to fit a tracer module they already produce as well as machine a pocket into my new G&P receiver to fit a fancy halo style LED activation switch.

To much relief, the machine work was successful and I’m finally happy with the result – could this M4 DSG build (dubbed ‘Phantom’) be the Carslberg of M4 DSG builds?

For those that are interested, here is the spec of the build as it is now:


BTC Spectre V2 MK2 mosfet
SiegeTek 20.8:1 DSG sector & spur gears
Lonex spiral bevel & pinion gears
KoA blueprint 16TPA motor
Maxx 21.25mm air nozzle
Retro Arms V2 M4 gearbox
Retro Arms CNC Cylinder Head (V2)
Retro Arms Steel Cylinder (B)
Retro Arms Custom Tracer Hop Chamber
Retro Arms CNC 8mm Bushing (LP)
Cyma Piston (short stroked full metal rack)
Prometheus EG spring guide
Prometheus purple hop rubber
235mm EDGI SS 6.01mm barrel (r-hopped)
Guarder M150 spring
Guarder tappet plate & spring
Air-Pad buffer pad
Viton O-Ring


G&P BAD Signature M4 receiver
G&P MOTS II 10.75” Phantom keymod rail
G&P outer barrel (machined to size)
G&P waffle pistol grip
Future Tech 3D printed dust cover
Big-Dragon ambi mag release
Maxx type E speed trigger
PTS Fortis Shift short grip
PTS GoGun Tactical Talon flash hider
Strike Systems ATS M-Stock
Castlelan extended backplate and nut
Opsmen Fast 301 flashlight
Vortex UH-1 holographic sight
LED halo activation switch for tracer


Jacob · September 30, 2020 at 12:24 pm

Hello! What are the final FPS/RPS numbers? Regards

    axerite · September 30, 2020 at 12:32 pm

    Hi Jacob! FPS is around 280 on 0.28g BB’s and the ROF peaks at 47RPS

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