Airsoft Forum banner

Build-Off '23: Danerd's "Classic" M4 Edition

2K views 27 replies 6 participants last post by  danerd 
#1 ·
This thread will document my foray into a friendly build-off with @Leo Greer to see who can build (I guess) a "better" staple of the airsoft and firearm world: The M4A1 carbine. My build will focus on cloning my current-issue service weapon as close as I possibly can. Given that, I'll be focusing on the attention to detail I put into this and the overall realism of the platform. Rather than my traditional AEG, I'll dive down the rabbit hole into world of GBBRs. I have built a few GBBRs in the past, so Im familiar with the process. Im looking at two main platforms to build this off of: Western Arms and WE Tech. Both are reliable, have excellent aftermarket parts support and dont have too many issues with proprietary parts and can perform admirably given they are moderately tuned.

The specs for my build are:
  • 14.5" barrel with either a Government or "SOCOM" profile. The actual A1's all use the heavier SOCOM profile barrel as they have been proven to withstand extreme heat caused by near continuous firing that would otherwise cause the Govt' barrel to rupture. Though since this is airsoft this doesnt matter.
  • 4 or 6 position stock. Either will work as I have handled M4s with both. My basic training rifle had a 4-position stock, whereas my current-issue has 6.
  • Ambidextrous fire selector. All M4A1s have this feature to better accommodate leftys like myself.
  • Either a Colt or FN-Herstal marked lower receiver. Many people think that Colt makes the military's M4s. That's not the case anymore as Colt lost the contract, and FN was subsequently contracted to not only make, but also service the inventory. My BT weapon was actually an FN M16A2 lower that was re-built as an M4A1. The M16 markings were removed and "M4 CARBINE" was re-engraved over the same spot. "BURST" was quite literally XXXX'd out and replaced with "AUTO" subset underneath. My current weapon is a Colt-made M4 carbine.
  • KAC quad rail RIS up front.
  • LE-style stock
Sights vary. The standard is an F-marked A2 front sight post with an MA-Tech rear flip-up sight. Also used are the Aimpoint M2 and M4 CCOs and TA M150 ACOGs. The ACOGs having either a red chevron or green crosshair reticle. We also have the venerable LA5-C PEQ in tan. I was issued an Aimpoint M2 CCO with my weapon.

As for performance specs, I'll be happy as long as Im able to get close to 400 fps. As for a rate of fire, anything between 800-950 rpm is good enough as that is the typical cycle rate of our M4s. That may not seem fast, but its really something when that 30 round mag is gone in around two seconds.

More to come....
 
See less See more
#10 ·
Thanks!

3,000 psi shouldn't be too bad, depending on the pump. In my opinion the biggest issue with hand pumps (and Yong Heng type compressors) is the moisture/oil levels if additional filtration is not used.

I try to only use my hand pump indoors when the humidity is high outside.

In regards to YH compressors, a good quality water separator and a filter tower filled with 13x molecular sieve should get you some pretty dry air as long as the separator is drained regularly and tower material is changed on time.

I have not sent off a YH sample for purity testing, but will this year. For comparison, my latest air purity tests from my scuba compressor came back with a relative humidity of -96°F and no oil vapor using a triplex filter (activated carbon, 13x, and monoxycon).

Sorry for the long winded reply!

DW
 
#6 ·
Darn it, I thought you were going to make a thread for your build @Leo Greer. Oh well...

I too am a nut for accurate platforms. If I go with the WE platform, I have a setup I used back in the day that performed phenomenally. If I go WA, I'll be swapping the hopup unit to one that allows me to use AEG packings and barrels and from there I'll use one of my go-to setups with an IR-hop. I also found my old barrel lapping kit, so this should really get interesting when it comes to accuarcy - though I think Leo may edge me out here since I have far more things affecting me than he does.
 
#9 ·
I try to keep as many stock/factory parts as I can. But my process is as follows:

I enlarge the barrel window to match that of the hopup unit I'm working with. I'll also deepen the window to better accommodate an Rhop patch, file and round the edges of the barrel window to remove any burrs and edges, and prevent pinch-jams with the patch.

I'll shim the hopup arm if it's needed and install an Mnub on the arm as well. The nub is cut-to-fit the patch and hopup window. I use a soft packing to help with airseal and teflon tape is used as needed to perfect the packing-hup unit seal. I'll also "barber pole" the barrel if I need to really stabilize things or clear up any slop between the inner and outer barrels. I also thoroughly clean and degrease the inner barrel and then If I really feel like it: lap the barrel to around a 20 micron finish. I don't lap all of my barrels as I find they perform well enough with everything I do already. I generally use 6.03-6.08mm barrels and I have found the wider bores usually perform better than the tighter ones.


In an AEG M4, my go-to for the past 11 years has been:

Lonex M4 hop unit
Prommy 6.03 barrel
OR
Stock/Factory
Lonex 50d packing
Rhop patch + Mnub

The entire setup can run you as much as $20 if you keep the factory barrel or as much as $85-90 if you add the Prommy barrel. Either way it's a fairly cost-effective way to get excellent performance with a little time and effort.
 
#13 ·
After an almost obsessive amount of research, Ive decided to go with a Western Arms platform. I did however find that WE makes an FN-marked M4A1 that is 98% of my service rifle for about $400...plus another $125 to have it shipped and another ~$60 to get the externals exact. Id be in almost $600 for a base rifle with no tuning or "upgrades" and Id only have 1 mag... The WA should a bit less.

I have a number of items on order from overseas that hopefully will arrive in a somewhat timely fashion. I do still need to order a proper charging handle as the airsoft ones have a disturbing tendency to break, which results in me getting a bloody nose from it breaking during use and me punching myself in the face. Im not dealing with that, but I need to wait until things arrive before ordering anything. I'll use the charging handle from my actual M16 to test the fit and function. I also need to get serial numbers, part numbers and cage codes so I can get some custom decals made up.
 
#14 ·
I managed to get an absurd deal on some WA goodies from a forum member (who shall be named in due time). Those will arrive this week and should provide an excellent base that I can tinker with until things come in from overseas.
 
#15 · (Edited)
Big thanks to @Graybeard for really delivering on some good stuff! The items I ordered from overseas have finally left the engravers and are on their way here to the States. We'll see if they managed to get the markings correct.
 
#16 ·
The items I ordered overseas arrived today (somehow going from Taiwan to Ohio in 48 hours). The markings on the receiver are 100% identical to my service rifle, sans the serial #. I did forget one item: the MA-Tech rear sight. Am I worried about it? No. Does it bother me? Yes, yes it does. I do have one item left for the externals; the UID tag. I needed to get the body in first to see what the serial # is so I can get that aspect of the tag correct. Now begins the process of tearing things apart and re-building them into the new body!

@Leo Greer Im closing the gap on that lead that you have!
 
#18 ·
@aotsukisho

I discovered there is a major issue with the lower: the buffer tube threading is not to spec. At all. I've tried a G&P, King Arms, heck I even yoinked the tube off of my actual M16 and it didn't thread whatsoever. It seems that the threads aren't wide enough to accept any of the buffer tubes I have. I'll have to futz around with it some more. Absolute worst-case scenario is Plan C.

Plan B loses the accuracy of the clone, but is still "close enough" I guess....


Plan C loses the "cool" factor, but is still a "classic" M4 circa say.... 2007-2008 ish.
Gas Machine Automotive tire Audio equipment Auto part
 
#19 ·
I ran into the same problem with a VFC build I did. I was installing a Mil Spec threaded UGS(P*) onto it. I ended up picking up a thread tap and retapping. This may be an option for you. The other thing, mabye the VFC 416a5 tube may work in place? Not 100% sure what the plan is, so these ideas may not apply.
 
#20 ·
Oddly enough I found a threaded AEG buffer tube that "works". It doesn't have an end cap (it did, but chances are I threw it out or it's gone to the Realm of Missing Things). I'd have to modify it quite a bit for the buffer and spring to clear one end, and I'd have to either find the cap or fashion one. It threads, but not all the way and I'm concerned that may cause the bolt to jam and lock up on the exposed threads.

Getting clearance on the one side is simply time with my dremel and then finishing to a glass-like surface. The end cap is more difficult as I'd have to make it from scratch if I can't find the original. It will have to fit and not come loose/undone. I'm thinking I can fashion one that is both adhered and/or pinned in place. It has to be 100% failproof with the abuse it will be taking.
 
#22 ·
The issue with that is there would be a very thin amount of material to retain the cap, buffer and spring. I'm worried about that failing during use and the buffer shoots out the back of the tube. Then the BCG gets stuck halfway in the upper and the tube and that type of thing is an absolute nightmare to fix.

The tube already has a slot in the bottom for a screw to sit for the old endcap. I can simply use that as a location for a roll pin and pin the new endcap in place there.
 
#24 ·
I was messing with the fitment of things again last night and came to another issue: the chamber portion is is too narrow to allow the barrel extension (the piece that is essentially the chamber) to fit. [emoji849]

Half an hour with my dremel seems to have solved the issue and now a G&P WA-spec chamber fits nice and snug as it should. It's potmetal and I don't have too much faith of it lasting long. A steel one is on the docket of parts I'd like to pickup for it for longevity's sake. I'm somewhat concerned with fitting the lower FCG parts. If I'm running into this many issues with just key externals, it's making we wonder what else may be off...

Also, curse those who think it's funny to put a 5mm Allen screw down an A2 pistol grip. There is a reason I cut a slot in all of my pistol grip screws for this type: it's way easier to just grab a flathead and do things.
 
#25 ·
Also, curse those who think it's funny to put a 5mm Allen screw down an A2 pistol grip. There is a reason I cut a slot in all of my pistol grip screws for this type: it's way easier to just grab a flathead and do things.
Hex driver, 1/4" socket/bit driver, and even a Torx driver are alternatives you could try. T27 should fit in 5mm hex.

I'm in the opposite camp, I dislike flathead type screws as flathead interface does not force the driver to be centered axially or flat against the head
 
#26 ·
More messing around this evening has resulted in nothing but issues. This receiver set is terrible:

  • The trigger and sear holes are good, the hammer hole is slightly off...as in not even aligned.
  • The slot that houses the bolt catch and firing pin unit is off enough that the unit doesn't even fit. If that wasn't enough, none of the 4 bolt catches I have even fit by themselves.
  • The threading on the upper is somewhere between Metric and Imperial. How this was accomplished I have no idea... But I have known Metric and Imperial threaded delta ring assemblies and neither one thread.
  • Did I mention the buffer tube? I think I have...

Plan A is very quickly turning into a quagmire. I'm more than likely going to cut my losses before they pile up even more and cause me to throw what is left off of my 10th floor balcony to see exactly how high it will bounce off the street below.

Plan B, while not optimal will hopefully prove to be somewhat more fruitful.

However

Messing with the magazines doesn't give me too much hope. 2 hold gas as they should. 3 leak from the fill valve, 3 more leak from the lip seal and 1 vents gas out of every little hole there is. Luckily I do have spare fill valves I can try. Perhaps these will remedy the 3 that leak from there. Whatever the case, I don't plan on fielding this anytime soon, if ever. It will be a nice little training aid though.

Then there leaves Plan C.... This...this may actually work out. I'll have to see what comes of my efforts tomorrow with everything else.
 
#28 ·
So, Plan B is a thing. Only thing done to it the addition of the KAC RIS up front and the M2 CCO It had a terrible amount of wobble, but it fits.

A quick chrono on 70F (ambient), .28s and propane gave me a 10-shot average of 402fps (~2.12J). That is beyond BASR limits for the fields around me. I'll keep futzing with things to see how far I can take things with the other body.
Air gun Trigger Machine gun Gun barrel Wood
Air gun Trigger Machine gun Gun barrel Wood
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top