Qlong's Seven incher SBR M4 - Real steel WE build - [WARNING: Extra Pants Required]

[Qlong]

Now for the build.

Upper receiver
I opted to go with a real steel VLTOR MUR this time as I have heard and personally experienced some problematic issues regarding brittle fractures at the barrel attachment point due to poor material choice and design.




From left to right we first have the 1st generation WE 416 where the walls at the barrel attachment points are 1/8 inches, the middle is a 2nd generation WE 416 where the wall are now reinforced with a thickness of 3/16, and a DYTAC MUR with thickness of 1/8 inches.


Make sure you find parts that are of the same version.


Now to solve this problem of fractures at the barrel attachment point I decided to go with a real steel VLTOR MUR upper, forged and milled from a billet of 7075 aluminum, it best not fail. As you can see I had to JB weld my previous 416 upper, it was fractured during production or shipment.

Now there are a couple of dimensional differences between the WE and RS upper, mainly being the internal diameter of the bore. The WE has 2 diameters, the larger being the same as RS starting from the top of the barrel attachment to the end of the threads, and then a smaller diameter throughout the upper, this is to hold the inner barrel/hop up assembly in place.



A number of WE M4 owners have the problem of the bolt not locking back most or all of the time, this issue can be commonly caused by:

• Insufficient surface contact of the bolt and bolt stop
• Angled contact between bolt and bolt stop

A solution to this would be to add AEG shims between the bolt stop and lower receiver. Instead of faced contacting like --> // <-- which shears off at an angle, they will contact like this -->||<--


In addition to this step if your bolt stop continues to fail, or if the face is worn, you can braze on a thin sheet of steel, about 0.75ish millimeters. It was shaped into an "L" and brazed at the end using a propane torch and silver solder. It has been locking 100% after 10+ mags. The extra bit of material helps as more surface area of the lock contacts the bolt.

This method is not permanent and may be replaced or removed in the future

Another method would be to tack a bead of weld, then file it down.



Another modification is needed in order for the MUR upper to fit due to clearance issues. Internally, the RS upper is not wide enough to accept the "mech box", which protrudes 1 or 2 millimeters from the top of the lower receiver.

From left to right we have, WE, RS VLTOR, and DYTAC. Notice the upper receivers all have different relief cuts in the walls.



The VLTOR upper has thicker walls and no relief cuts so for the lower receiver to clear this, either the walls have to be machined thinner or the "mechbox" has to be made thinner. I chose the latter.







Lastly, the barrel attachment point has the most noticeable difference as 3 cuts can be seen on the WE and only one on the RS. On the WE, the cuts keep the inner and out barrel from freely turning.



Since the WE barrels have 2 protruding notches on opposite sides, it is necessary to remove them in order to fit on top a RS upper.

First, a step must be taken before the removal of the notches. Since the RS upper does not have that smaller inner diameter ridge to keep the inner barrel assembly from sliding back into the upper, an alternative method must be utilized to keep this from happening.

What I still need to do is to drill and insert a roll pin at the 12 O’clock position into the barrel spacer, this acts as the locator pin and keeps the barrel in place.



Another way to keep the outer barrel in place is take the barrel spacer and outer barrel, affix them to each other, put them in a vice and crush the notches into barrel spacer. This is a more permanent way of affixing the barrel to the spacer, however there are many other methods, I chose this because I don’t plan on un-assembling them.





Here is the bolt with the pin which allows the bolt to be pulled back by the charging handle.

I did not wish to mod the RS charging handle so I opted to mod the bolt instead.

This is from WE M4 Guide - http://wem4guide.wikidot.com/modifications,

She's finally done. I think.

• BCM Gunfighter Mod 3
• Battle Arms Development BADASS
• DSA Stock Tube Mil-spec
• Magpul ASAP
• Magpul CTR [Mil-spec]
• Magpul MIAD Grip
• Magpul EMAG
• Magpul PMAG
• Magpul RSA
• Magpul XTM Rail Covers
• PMC 7" Barrel
• TSC Anti-rotation Links
• TSC Gear Sector Hand-Stop
• Troy Ind. Battle Rail Covers
• Troy Ind. Modular Combat Grip
• VLTOR MUR Upper receiver
• WE Stock Lower
• WE HK 416 Sights
• Unknown Make 7.5" DD RIS II

[Frozen Tex]

Holy Crap! Merry Christmas to you...!

Nice gun, dude.

[ILLusion]

woah. 7" boner. Nice. LOL

first time i've seen the magpul clip rings. what are those rail covers? I've seen them before, but can't recall the manufacturer.

[Frozen Tex]

I see Troy Industries printed on a rail cover...

[Tex]

[WARNING: Extra Pants Required]

Pants changed,

Fuck you. that is all.

ok maybe not ILLusion those are troy covers.

[ILLusion]

Originally Posted by Frozen Tex

I see Troy Industries printed on a rail cover...

doh. I didn't bother expanding the image.

Regarding the RSA... is it necessary to put it on both sides? Seems overkill to me, considering the MS2 / MS3 when in 2-point mode was meant more for slinging the rifle/carbine to your back when you need both hands, and when in direct action, you would be engaging with a single point.

Anyways, that's just how I see and would use those tools. I'm sure each operator would use it their own way. It depends on your training.

[Qlong]

Now I have to figure which can to put on.

AAC, KAC NT4, Gemtech G5, or Surefire

Originally Posted by ILLusion

Regarding the RSA... is it necessary to put it on both sides? Seems overkill to me.

It was purely cosmetic, I just had a little extra uncovered rail left, why not just use the other RSA to make it symmetrical?

I love overkill.

[juicy]

Looking good! I think a G5 would look great on there. Dunno what the Surefire even looks like, though.

Needs more lights. I'm thinking somewhere around 4 - 2 double mounts on each side to keep things symmetrical, lol... just kidding, please don't.

[Boyso]

That is awesome.

I need a GBBR

[Kozzie]

Droolzz

I have your family, give me the gun or they will die! ...lol

[Penguin]

Ohhh I wish I were loaded.

[TokyoSeven]

Lookin good Q
Lookin good

Great build with great detail.

[manchovie]

love it.

[baker_Jeff]

Fantastic!

[Short Round]

I looked at that photo and jizzed in my pants, I thought I was dreaming then looked again and I jizzed in my pants. That gun was so sexy that I jizzed in my pants.