Sunday, September 16, 2012

My M4-Based SBR Build: Upper Receiver Assembly

I have completed the second assembly for my M4-Based SBR build, and it is the Upper Receiver Assembly. Total price was at Php 22,466 (approximately Usd 535). Again, by US standards, it is shockingly expensive, as it is almost the price of some basic M4 Rifles I have seen on US websites. 

But that is life here in the Philippines, where owning firearms is not a right but a privillege, meaning only those who can afford can legally get one.

‘Parts Breakdown and Details'
Here is a breakdown of the parts of the assembly, and posted alongside each are the prices and where I bought them (note that all the prices included Shipping Costs wherever they apply. If the parts came with multiple shipments, I just divided the Shipping Costs with the number of items that arrived):
- Elisco Bolt Carrier Group (BCG), Php 6,800 (Online, Philippine Pistol Forum)
- Rock Island Armory M16 Upper Receiver, Php 12,000 (Twin Pines MCS)
- Ejection Port Cover Assembly, Php 1,100 (Final Option SM Megamall Gun Show)
- Forward Assist Assembly with Round Handle and Roll Pin, Php 916 (Online, Ebay.ph from US location)
- Charging Handle Assembly with Tactical Latch 1, Php 1,650 (Online, Ebay.ph from US location)

Here are the pictures of the assembly:
Right Side of the Upper Assembly


Left Side of the Upper Assembly


View of the Major Sub-Assemblies of the Unit


'Assembly and Instructions'
I needed instructions on how to put all of it together, specifically in terms of assembling the Charging Handle, BCG, Ejection Port Cover Assembly and Forward Assist Assembly (FAA) into the bare Upper Receiver, and I was able to do that with the help of this video on Youtube:

http://www.youtube.com/watch?v=0J57W4xz6Uw&

I didn't use Vise to install the FAA, though. Just a pocketbook and somebody else to hold the Upper Receiver while I punch the Roll Pin in.

Picture of the setup used to install the Forward Assist Assembly


Most of the assembly process did not require press fitting, except for the Forward Assist Assembly, which needed to be attached to the Upper Receiver by Press-Fitting a Roll Pin to keep it in place. Because of this, I decided to buy a Roll Pin Punch Set from ebay.ph (shipped from a US location), it costs me P 1,360 (USD 31).

I bought a set instead of only one Roll Pin Punch because aside from the Forward Assist Assembly, some other parts on the Lower Receiver will need to be attached via Roll Pins also. Roll Pin Punches are needed to neatly and easily punch those Roll Pins in because otherwise, it will be difficult and messy. The set I bought had all the required Roll Pin Punch sizes for all of the Roll Pins on an M4, which are diameters 3/32", 1/8", 5/32" and 5/64".

Picture of the Roll Pin Punch Set


'Fit Observations'
During assembly, the BCG slid in easily into the Upper Receiver, but the Charging Handle required some effort to do so, especially on the slot where it is supposed to be inserted. Once in, though, the Charging Handle easily slid back and forth. However, when I needed to remove or install it again on the unit, it is still a bit tight and needed some muscling in or out.

A slight problem with the Forward Assist Assembly wherein its bottom part was rubbing against the frame and removing some of the finish (see picture of the setup used when installing the FAA). But the problem is purely cosmetic in nature, the FAA freely moves back and forth easily within the Upper Receiver.

There is also an irritating issue with the Ejection Port Cover Assembly: It won't stay closed on the Upper Receiver. I am not sure which is at fault, either the Ejection Port Cover, or the Rock Island Armory (RIA) Upper Receiver. I suspect it is the Upper Receiver, the portion where the Ejection Port Cover is supposed to "latch on" to seems to be too thin and not adequate for latching on to.

Picture of the Latch Area, which seems to be the culprit for the Ejection Port Cover not Closing


The RIA Upper Receiver is made here in the Philippines, and it seems they need to improve their Quality Control more a bit. In fairness, I searched the web and this seems to be a common problem with the M4, where the Ejection Port Cover will not close, except on some higher quality Upper Receivers. I guess that means these RIA Upper Receivers are not that high in terms of quality, then. But they are cheap, so I guess I got what I paid for. I hope the problem only remains there, and no other problems will manifest itself during actual firing.


Sources:

- Twin Pines Philippines website, http://www.twinpines.com.ph//

- Pinoy Pistol Forum, http://www.pinoy1911.net/forum/index.php

- ebay Philippines website, http://www.ebay.ph/

- Final Option website, http://www.finaloption.com.ph/content.php



Related Posts:

--> My Planned M4-Based SBR Build

--> My M4-Based SBR Build: Buttstock Assembly

--> My M4-Based SBR Build: Sighting System

--> My M4-Based SBR Build: On Hold Indefinitely

15 comments:

  1. Sir may nabili na po ako na upper receiver sa mcs pero 15k po inabot may ksma na epc at forward assist. US made sya. Problem ko na lang ung barrel na 11.5 out of stock sa twin pines ung 7.5 nmn pang .223 lng daw. Gulo nga e last week meron tpos nwala bigla. Baka nexyear na ang balik. Bumisita ako s gunshow wala dn po daw barrel. Try nyo po sa true weight sa araneta baka may magustuhan kyo lower dun n resonable presyo. May gas block na po kayo? Thnx sir

    ReplyDelete
  2. Salamat sa tip, Gino. Tingnan ko one of these days.

    Ala pa akong Gas Block, balak ko pag nabili ko na ang barrel, saka na ako bibili ng Gas Block, kasi iba-iba rin kasi ang size niyan.

    Merong Low Profile na Gas Block para nakatago sa ilalim ng Hand Guard, at meron ding yung kasama na ang Triangular Front Sight, depende na kung alin ang gagamitin mo.

    ReplyDelete
  3. hi good day where can i buy this here in the philippines?
    1. upper and lower receiver
    2. barrel 11.5
    3. gas tube
    4. internal parts

    ReplyDelete
  4. deck,

    The current Philippine government has become strict with the purchase of firearms and their parts and accessories, so right now the main way that this can be done is by getting them from the gun stores. There is a number (more than half a dozen) of gun stores at the BASEMENT of the MAKATI CINEMA SQUARE (MCS), so right now that would be your best bet.

    Sometimes they are also available on the local firearms forums, but not so much anymore, you can check that out also.

    ReplyDelete
  5. Hi! Mi alam ka pa po ba nag benta ng good condition elisco bcg? Thanks

    ReplyDelete
  6. Your best bet will probably be the local firearms forums. And there's always the MCS gunstores at the basement ...

    ReplyDelete
  7. Good Day po mga Sir, saan po ako pwedeng bumili ng Flat Rail Upper Receiver para sa Bushmaster ko?

    ReplyDelete
  8. Best bet Junriel would be sa mga gun stores sa basement ng Makati Cinema Square. You can also try yung mga local gun forums katulad ng Pinoy 1911 forum. Good luck ...

    ReplyDelete
  9. Also me Gun Show sa middle of November 2015 sa SM Megamall, mas maganda dun kasi mas marami nag bebenta at makakapamili ka ...

    ReplyDelete
  10. dito po kasi ako sa Mindanao Area sir,

    ReplyDelete
  11. need pa po ba ng requirements to purchase said item?

    ReplyDelete
  12. Medyo malayo, kailangan mo talagang dumayo. Sa Davao City alam ko maraming mga Gun Stores dun na kung saan ka puede bumili.

    ReplyDelete
  13. Ang alam ko e kapag Barrel at Lower Receiver lang kailangan ang requirements, pero para sigurado dalhin mo na yung lisensiya ng Firearm mo ...

    ReplyDelete
  14. Sir rhk111, baka may kilala po kayo diyan na nagbebenta ng hinahanap ko, baka pwede nyo ako matulungan. PNP member po ako dito sa Mindanao, Region 12.

    ReplyDelete
  15. sana matulungan mo ako sir, salamat po. . .

    ReplyDelete