SRC M4 upgrades thoughts and advice please

[AJBRUCE4884]

Hi everyone,

So I recently bought a knackered SRC gun and completely transformed it internally and externally. The existing gearbox wasn't working, the motor span and the gears were spinning but nothing was happening. I was going to strip it down and replace the internals with upgraded parts, however, I couldn't get the old screws out......they were in there solid! Externally the gun was a little lacking too, I wasn't keen on the looks of it and decided I was going to build a gun I would be overjoyed with from a number of different parts sourced from all over the net.

What I ended up with can be seen below. I've yet to get a forward grip (thinking a PTS Fortis style grip) and I was also wanting to add some 45 degree rapid transition sights.



So, the upgrades are as follows (front to back):

Generic 14mm CCW thread 196mm barrel extension/mock silencer with US Delta force logo
Noveske 15" Key mod rail system in tan
OD 4mm bungee cord on each side
ARES Octarms 2.5" keymod rail attachment
G&P SR16 E3 heat sink outer barrel 410mm long
PTS Fortis low profile mock gas block
mock gas tube
ASG grey 85rnd magazine
ambidextrous magazine catch
FMA M4 AEG anti-rotation links (do not serve a function other than aesthetics)
VISIONKING 1.25-5 x 26mm Red/Blue scope with Element LaRue SPR QD mount
Butterfly charging handle
MAGPUL pistol grip (replica hong kong type......actually spelt MAGOUL haha)
MFT Battlelink minimalist mil spec stock in dark earth

INTERNALLY:
SHS M120 7mm bearing gearbox (rear wired)
Madbull 60 degree shark accelerator bucking
PROWIN hopup unit
JBU 6.01mm 550mm inner barrel
Nuprol High torque motor
Deans wired and running 11.1v LIPO battery.

So, externally I am more than happy with the gun, it looks the business and I can't take my eyes off it each time I open my gun case! Internally though I'm a little unsure. I've never had experience with SHS products and am unsure what they're like. I have seen a lot of videos and reviews of people recommending SHS products, but would like to know other peoples experience and thoughts on this gearbox. The experience I have had is that it shoots pretty well, not sure on FPS or range but I'd imagine with the M120 spring and tightbore it should be around 380fps?? I chose the SHS gearbox for expense over anything else. Having spent so much on the external elements I was reluctant to spend so much more on the internals, especially the gearbox! I got this new for around £50 which I was happy with. I contemplated a Lonex or an Ares or G&P but the price of these were far more and I wasn't sure they would be that much better.

So, I turn to you good people of the ******* ***** to impart your knowledge, advice, criticisms and/or complements and let me know your thoughts on the above build. Should I stick with what I have or upgrade to a lonex or other? Also, should I upgrade with a MOSFET too.....I don't know too much about these but my understanding is that they're a lot better?

I look forward to heating from you.
Cheers

[46templar]

Re: SRC M4 upgrades thoughts and advice please

Ive got a great idea for your gun you can give it to me please it looks bloody tasty mate

Sent from my GT-I9505 using Tapatalk

[sj_asc]

Re: SRC M4 upgrades thoughts and advice please

Regarding the choice of internal parts brands listed compared, from knowledge and experience I can say;

Don't even consider the Ares for anything.

Gearbox shell - Lonex has the edge over the SHS here thanks to actual front end reinforcement and general all round good quality. These have better compatibility with TM spec parts and will withstand some real punishment - far beyond what we are allowed to run at sites over here.

SHS Gearbox Internals - The SHS M120 spring, providing there are no excessive leaks elsewhere in the system and that the QC has the spring labeled correctly will be pulling in over 400fps w/.2g. Some SHS pistons are good (modified 14 or 15 tooth variant). The SHS 7 tooth is also super reliable when you are talking mild upgrades. Spring guides, Nozzles, Switch, Cut off mech, AR latch,Tappet plate, Gears are very nice and you should have no worries here, the only parts I would suggest swapping out are the 7mm ball bearings - for steel bushings instead. IMO SHS gear sets are better value for money and offer more of a range and if paired correctly (sector bolts locked down and using a 9 tooth bevel instead of 10 tooth) and under pressure will undoubtedly outlast the Lonex equivalents for a fraction of the price - anyone who wants to challenge this is welcome

Motor For internals, Nuprol just stick their names on other existing products, the motor will perform undoubtedly better thanks to the use of neodymium magnets (torque/trigger response), however what you pay and what you get don't match up to what is available. In short, it's nothing special but will do the job.

MOSFET - Highly recommended, particularly if you have a new motor that is likely to want more juice, a properly wired in FET will not only fully protect the mechanical switch against burn out, but also significantly boost the efficiency of the wiring loom (providing that you have removed all bottlenecks such as motor spade connectors and to have fitted low resistance battery connectors). The firestorm MOSFET is probably the best cheap standard FET on the market and comes with a enough 16awg wire to rewire the whole gun and lifetime warranty. From experience they noticeably improve the trigger response and sometimes even rate of fire of every gun I have installed into. If you want fancy functions then there is also BTC, but they are quite hard to find as its a cottage industry manufacturer and stock disappears very shortly. They are also nearly 10 times the cost of a standard FET, so unless you want fancy functions and or have a lot of money to blow, then a standard FET is fine.
In addition to the FET, Be sure to run a high output LIPO (Capacity and C rating) to allow for maximum trigger response (shortest spin up time).

Hop chamber - Depending on which route you want to take for future hop modifications, the Pro-win unit is very nice, however for flat and r-hopping is sub par compared to the other aftermarket copies of the stock chamber design (Lonex, Prometheus, SystemA etc). From experience, the Pro-win chamber can sometimes need shimming from the front of the GB shell to either to correct seal or feeding issues.