Building a 5.56 Patrol Carbine for the Wife

[survivalshop]

8 hours ago, AngelDeVille said:

I got your PM, yes I take PayPal.

      Thanks , it will look good in my collection .

[COBrien]

On 1/17/2018 at 11:02 PM, Robocop1051 said:

Ps. The DD Mk18 comes in a complete upper. It’s practically perfect right out of the box. BCM makes a comparable 10.5” with their Alpha rail. 

The DD is nice, but that price? FFAAHH. Even OpticsPlanet and Primary Arms, who have been my go-to for the lowest prices on parts, sell them for $1146.

I'm looking at a FA upper, Criterion/ADM 10.5", Troy SOCC 9.25" rail, FA upper parts, and Troy fixed front sight (with a MaTech rear that was, erm, "donated" by a friend who has several) for a grand total of $750ish.

Edited January 22, 2018 by COBrien

[Rsquared]

The DD MK-18 can take a pounding and keep on going. We probably ran about a thousand rounds through mine back at the fall meet-up shoot. And that was with many, many mag dumps. The night shoot video, with GREG running that thing is awesome. It's on here somewhere.

Plus, that thing is still deadly accurate with the EOtech 553 for short to mid-range work.

Edited January 22, 2018 by Rsquared

[Robocop1051]

41 minutes ago, Rsquared said:

The DD MK-18 can take a pounding and keep on going. We probably ran about a thousand rounds through mine back at the fall meet-up shoot. And that was with many, many mag dumps. The night shoot video, with GREG running that thing is awesome. It's on here somewhere.

Plus, that thing is still deadly accurate with the EOtech 553 for short to mid-range work.

I may have broke several federal laws when playing with your Mk18. In order to get the best possible trigger speed, I took your Mk18 upper off your registered SBR lower and swapped it to another lower with a 3G trigger... I can neither confirm nor deny whether the second lower was also a registered SBR lower. We’ll just have to assume that I would always play within the confines of the law... even if conceivably inebriated and afflicted with poor decision making.

here are my three retina burn videos. I honestly couldn’t see shit after this. All are the Mk18. The first two are with a 3G trigger. The third is with the original trigger from the SBR  

 

[sketch]

that is sick trigger trigger control!

[Armed Eye Doc]

I'm looking to get a binary trigger to be half as good as Greg and a quarter as good as GREG.

[98Z5V]

On 1/22/2018 at 10:41 AM, COBrien said:

The DD is nice, but that price? FFAAHH. Even OpticsPlanet and Primary Arms, who have been my go-to for the lowest prices on parts, sell them for $1146.

I'm looking at a FA upper, Criterion/ADM 10.5", Troy SOCC 9.25" rail, FA upper parts, and Troy fixed front sight (with a MaTech rear that was, erm, "donated" by a friend who has several) for a grand total of $750ish.

There's a 5.56 velocity drop that follows barrel length.  There's a significant velocity drop when going from 11.5" down to 10.5" barrels.  The effectiveness of the 5.56 round comes from it's fragmentation after penetration.  That all hinges off the velocity.  I did alot of research when building my first 5.56 pistol, and dug for alot of information about it, and almost all the information came from studies and presentations from Doc Roberts (DocGKR, if you search him out on other forums).  I went with the 11.5" barrel, to increase my distance.  If I remember correctly, my maximum range (for reliable fragmentation) was 175 yards with the 11.5" barrel, but that range dropped down to something like 75 yards with a 10.5" barrel.  That made my decision for me, and I went with the 11.5". 

You have to remember the reason for the Mk18 CQB rifle configuration, with it's 10.5" barrel - it's for short-ish range CQB.  Nobody that uses that weapon as it was designed is even worried about targets at 75 yards.  Their furthest target is "How big is this room or hallway?"

Something to think about for a patrol rifle.  Hell, even a 12.5" barrel with midlength gas would be a little better than the 11.5"er.  That 12.5 setup is referred to as a "Kino Configuration."

[COBrien]

2 hours ago, 98Z5V said:

There's a 5.56 velocity drop that follows barrel length.  There's a significant velocity drop when going from 11.5" down to 10.5" barrels.  The effectiveness of the 5.56 round comes from it's fragmentation after penetration.  That all hinges off the velocity.  I did alot of research when building my first 5.56 pistol, and dug for alot of information about it, and almost all the information came from studies and presentations from Doc Roberts (DocGKR, if you search him out on other forums).  I went with the 11.5" barrel, to increase my distance.  If I remember correctly, my maximum range (for reliable fragmentation) was 175 yards with the 11.5" barrel, but that range dropped down to something like 75 yards with a 10.5" barrel.  That made my decision for me, and I went with the 11.5". 

You have to remember the reason for the Mk18 CQB rifle configuration, with it's 10.5" barrel - it's for short-ish range CQB.  Nobody that uses that weapon as it was designed is even worried about targets at 75 yards.  Their furthest target is "How big is this room or hallway?"

Something to think about for a patrol rifle.  Hell, even a 12.5" barrel with midlength gas would be a little better than the 11.5"er.  That 12.5 setup is referred to as a "Kino Configuration."

My original intention (well, not "original original"...) was to build her a 12.5", either carbine or mid gas. 10.5" FF rail, yadda yadda.

But the other SRT guys are now running RRA 10" left-side-chargers, and she wants to hang with them. I'm about 95% sure she's never fired a 10" SBR, but I have. While it's fun for a bit, I wouldn't want to do it without muffs. Or in the dark. And damn sure not indoors, dimly lit, without muffs.

But maybe she's more of a man than I am.

[98Z5V]

That brings up another point, and I forgot about it - Concussion.

When I built that 11.5"er, I just slapped a spare A2 flash suppressor on it.  I ended up liking it, and built a 7.5"er.  And I slapped another A2 on there...

First rounds down range rattled my damn teeth, I kid you not.  I put it in the range bag, went home, and immediately ordered a Noveske KX3 for it.  That ended the teeth rattling, for sure.  The concussion off the 7.5"er and an A2 is unbearable.

More to think about, and consider.  She should shoot one of the other weapons - and those guys should do some fragmentation tests, and see how far out they can reach, while still getting their rounds to frag.  Those guns might look cool, but those guys might be shocked at the results...

Long story longer...  The 11.5" with A2 compared to the 7.5" with KX3 - the 7.5" gun is about 1/2" shorter than the 11.5" gun - because of the length of the KX3...

Edited January 23, 2018 by 98Z5V

[COBrien]

Good point, 98.

I stumbled upon the Black River Tactical "Covert Comp" and found one on sale ($45 vs. $60), so I ordered one up. Based on some threads I found online (admittedly, from like 2014...), the BRT was one of the better "compensator" solutions for an SBR, as far as concussion, noise, and (strangely, looking at how it's designed) muzzle rise. We'll see. It may not end up on anything for awhile, but I'll find something to throw it on...

Edited January 23, 2018 by COBrien

[AngelDeVille]

I plan on a 3 prong for my 10.5" 607.....

[survivalshop]

     I built a XM-177 copy ,select fire M16 , 10.5" BBL. with an original XM -177 Flash hider , the full auto mag dump was something to behold , it looked like a blow torch on night firing , probably 8-10 feet out . Wasn't much of a flash hider , but according to the BATF , it dropped the decibel sound signature 2 decibels & they considered it a Sound Suppressor & it could only be on a copy or an actual XM-177 M16..Not sure of they classify it the same way anymore .

  Looked just like this & no thats not me !

[AngelDeVille]

Yeah if I could put a "moderator" on it without fucktard restrictions I would.

 

It was only intended to make the carbine sound the same as a 20" barrel

[Rsquared]

On ‎1‎/‎22‎/‎2018 at 5:46 PM, Robocop1051 said:

I may have broke several federal laws when playing with your Mk18. In order to get the best possible trigger speed, I took your Mk18 upper off your registered SBR lower and swapped it to another lower with a 3G trigger... I can neither confirm nor deny whether the second lower was also a registered SBR lower. We’ll just have to assume that I would always play within the confines of the law... even if conceivably inebriated and afflicted with poor decision making.

here are my three retina burn videos. I honestly couldn’t see poop after this. All are the Mk18. The first two are with a 3G trigger. The third is with the original trigger from the SBR  

 

And that, my brother, is why I'm gonna change that trigger out to a S3G trigger. That was a FUCKIN example of firepower superiority. And just think......we still had 7.62 firepower ready to go after that.

The MK18 is probably one of my favorite (read as fun) weapons. Suppressed or not.

[StainTrain]

On 1/23/2018 at 4:52 PM, COBrien said:

But the other SRT guys are now running RRA 10" left-side-chargers, and she wants to hang with them. 

 

In what regards?  It was touched on earlier, but she needs enough barrel length to keep the velocity at a point so the bullet can do its job.  Looking cool do not end critical situations.  SRT's mission for the department isn't the same as patrol.  Just like bigger isn't always better in the bedroom, shorty isn't always better in a tactical environment.  Over the years, I have been issued a variety of SBR's from 10.5 -14.5 and aesthetics aside, my favorites are 11.5 and 14.5.  I have an 11.5 with micro RDS and 14.5 with ACOG/RMR.  The 11.5 only has an edge in vehicle operations (in my opinion). I run them interchangeably during CQB.  Although I don't know which of the CQB methodologies that particular SRT adheres to, I can say the types of missions that would be hampered (slowed) by those 3 extra inches fall into a VERY narrow category. 

The 12.5 is a legit compromise for a patrol rifle if you can find a manufacture that suits your needs. 

A properly built 11.5 -14.5 upper with quality components will "hang" with the SRT guys.   

[Robocop1051]

It's been shown that a 7.5" 5.56 will still perform up to 50 yards with terminal results. For LE, that's practically all the performance we need. I would feel perfectly OK with a 10.3" doing 100% of the things I need to do in my job.

[StainTrain]

Admittedly, I haven't seen the ballistics test of the 7.5 inch 5.56 so I can't really speak to that although 50 yards is certainly plausible for most 5.56 bonded ammo.  I am only privy to the testing on the 10.5 and up.   

Robo has an excellent point that there aren't a lot of Patrol Rifle engagements that will exceed 50 yards (likely single digit incidents nationwide each year) and your wife will likely be ok no matter which length she goes with.  I mean seriously the MK18  has a good track record of solving problems.    A short rifle with a reduced velocity bullet is preferable over a handgun.  

Edited January 27, 2018 by StainTrain

[Robocop1051]

3 hours ago, StainTrain said:

Admittedly, I haven't seen the ballistics test of the 7.5 inch 5.56 so I can't really speak to that although 50 yards is certainly plausible for most 5.56 bonded ammo.  I am only privy to the testing on the 10.5 and up.   

Robo has an excellent point that there aren't a lot of Patrol Rifle engagements that will exceed 50 yards (likely single digit incidents nationwide each year) and your wife will likely be ok no matter which length she goes with.  I mean seriously the MK18  has a good track record of solving problems.    A short rifle with a reduced velocity bullet is preferable over a handgun.  

Mmmm, the Mk18... You're making me drooooool....

If rails aren't your thing, there's also this option...

[StainTrain]

It's so sweet.  You slap a can on that and it is poetry in motion.  

[COBrien]

On 1/27/2018 at 9:51 AM, StainTrain said:

In what regards?  It was touched on earlier, but she needs enough barrel length to keep the velocity at a point so the bullet can do its job.  Looking cool do not end critical situations.  SRT's mission for the department isn't the same as patrol.  Just like bigger isn't always better in the bedroom, shorty isn't always better in a tactical environment.  Over the years, I have been issued a variety of SBR's from 10.5 -14.5 and aesthetics aside, my favorites are 11.5 and 14.5.  I have an 11.5 with micro RDS and 14.5 with ACOG/RMR.  The 11.5 only has an edge in vehicle operations (in my opinion). I run them interchangeably during CQB.  Although I don't know which of the CQB methodologies that particular SRT adheres to, I can say the types of missions that would be hampered (slowed) by those 3 extra inches fall into a VERY narrow category. 

The 12.5 is a legit compromise for a patrol rifle if you can find a manufacture that suits your needs. 

A properly built 11.5 -14.5 upper with quality components will "hang" with the SRT guys.   

I think her desire for an SBR is twofold (or maybe threefold):

1. Shorter barrel = easier in and out of the car in a hurry. As I posted above, she now has a rifle rack mounted to the back of her passenger's seat (I finally got the Santa Cruz lock and the necessary hardware in from C0, and it's GTG). These new Chargers sure don't offer much interior room when compared to the Crown Vics... Or even the pre-catfish Chargers.

2. It's what SRT is running, so she wants to keep up with the trend. Granted, she's a negotiator at this point, so she is less likely to be neck-deep in it should the fertilizer hit the ventilator, but she is still in patrol. In uniform. Every day.

3. SBRs are cool right now.

I'm looking at the ADM 12.5" Hybrid barrel (carbine gas) made by Criterion. That, with a Fulton M4 upper and a handguard of her choosing (I really like these Troy SOCC rails...), and some sort of linear comp (the BRT Covert Comp I ordered seems like a quality piece).

The upper will be riding on an old LESO M16A2 lower "owned" by her department. Depending on which lower she's issued (most of the SRT guys were issued LESO rifles prior to the SBR switch, and they swapped out buttstocks, grips, etc.), it will end up with a carbine buttstock of some sort.

Still on the fence re: reusing the M16A2 BCG or buying a new one for this upper...

If she is dead-set on something in the 10" range, CBI/ADM offers a 10.5" Hybrid with carbine gas.

[COBrien]

Well, Fulton Armory is having their 10% off sitewide sale for the month of February.

So, for Valentine's Day (in addition to "girly" stuff...), the wife is getting an upper, along with everything necessary to make it functional, sans barrel and gas tube.

We'll see what she wants to do re: the barrel...

[StainTrain]

On 2/12/2018 at 12:05 PM, COBrien said:

We'll see what she wants to do re: the barrel...

I can't believe you guys just let that go........

[98Z5V]

I almost said something... 

[AngelDeVille]

I thought she was already used to sbr's so I didnt think a comment was necessary.

[COBrien]

Ha.

But seriously, she's on the fence about barrel length. Stay with me here, because this is about to get weird.

Overworked, underpaid, and underappreciated leads to severe burnout. She's considering hitting her 10 years (December 2018) to be vested in the pension, then finding a new career. But, they have a new chief coming in in 2 weeks, so hopefully things will turn around. God bless that man for taking on this unabated dumpster fire. But I digress...

For whatever reason, she seems to only want an SBR if she's going to "stick it out" and stay where she's at. I reminded her a $200 tax stamp is all it takes to submit a Form 1, and we're golden. She says that's too much money.

What she doesn't realize is that I have a "suppressor fund" in a lockbox under my desk at work. Which I dipped into for a down payment on some jewelry for VDay. I may just dip into it again to pay for the Form 1, register the lower I gave her, and be done with it.

 

Having said all that... I would really prefer for her to go shoot one of those 10" RRAs, then shoot a buddy's 12.5" upper before making a decision. I'll build her whatever she wants, but I'd rather it be exactly what she wants the first time around.