What is your dream AR build? After all the home defense and rifle discussions, I started piecing together an SBR. So far this is going to be pretty damn close. I have a done a dozen or so builds (mostly for hog hunting), but this one is more a purpose built and bomb proof SHTF rig.

My wife is going to be pretty annoyed when those boxes start arriving tomorrow, and I am at a conference. Hopefully all the parts get here when I am away so I can build it this weekend. Will post pics.

Rifle:
LMT Mars Ambi Lower (will SBR
LMT 11.5 Shovelnose Monolithic Upper and Handguard
LMT Piston 12" 5.56 Barrel
LMT Piston G2 Chrome Finished BCG
Gieselle SD-E Trigger
Radian Raptor SD Charging handle
LMT Finishing kit for stock, grip, and lower parts

Muzzle Device:
Rearden Flashhider Plan B Muzzle Device
Huxwerks Ventum Suppressor (for now)

Optic:
Aimpoint Micro T2 with Unity Fast Mount

Light:
Surefire Scout light

Haven't purchased yet, but plan to:
Aiming Laser- Peq or Dbal (Mawl would be great but cost more than the gun)
Offset backup irons

Maybes:
magnifier
Law folder

Pic of a similar rifle.

What would you add? What is your dream build.

Whatever is in benders safe

This is the high quality content I'm here for. Very nice build.

Frisco said:

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Whatever is in benders safe

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So, funny story….





Close to the gun OP is building is in my safe.

LMT ambi lower, lmt upper (just the regular mrp, not the spec war so my entire gas block sticks out), 12" piston barrel/bcg. Acog and 45deg offset holosun on a unity mount, geissele h3 buffer/spring and irregular defense cheek riser.

I'm using a CGS Sci-Six suppressor but otherwise, pretty close.

I think you're really going to like that LMT, OP.

Have 2. Love it. As a lefty suppressed with hux 556k flow. Zero to nil gas whatsoever. Went with defender lower.

Unity is releasing their new 4x integrated optic and mount on the 13th.

https://www.bigtexordnance.com/product/unity-tactical-fast-ftc-4x-magnifier/

Other fave is the 11.5 DI.

Adding to bender.

The lmt piston 12inch barrel vs the 11.5 DI OR 12.5 di.

The piston is more front heavy. Noticeably. Not 30lbs difference but it's heavier

Have some friends on swat and one atf agent. Obviously they have handled rifles throughout the years.

Hand them the lmt piston. Their reaction is they aren't sure they would want to train or carry that for hours if on duty. I get it. Vs the Di lmt. It is heavier up front.

It's still badass though.

SMM48 said:

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Bender has the sig and has been through all the "if I knew then what I know now". Hopefully he'll reply again. I think he's a lefty

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Yep, left eye dominant.

So, 300blk....love the round. Problem you run into with 300blk and ARs is if you tune it to run subsonic rounds well its going to be really overgassed for supers, and if you set it up to run well with supers it may not have enough gas to cycle subs. The suppressor you use can make a huge difference too on that front (ill expand on this in a minute).

Sig's solution to this problem in a piston system was the MCX with a two position gas valve. (-) on one side for supers, (+) on the other side for subsonic (or adverse depending on which MCX and which gas valve we are talking about). It's better than not having any options, but obviously how well either option works for you is going to depend heavily on both your ammo and your suppressor.

My MCX Virtus had an original early 6.75" barrel, which was designed to be used paired with the Sig SRD series of suppressors. Which would be great, if Sig hadn't discontinued the SRD line. So when I tried to use my 6.75" barrel with a CGS Hyperion suppressor, I had a lot of function issues until I could get the upgraded gas valve Sig now uses on their new 6.75" barrels.

Sig MCX also has a 25 deg taper built into the barrel. You can work around this and use adaptors for conventionally shouldered suppressors and muzzle devices, but if you have or want to buy a can that has an internal 25 deg taper, direct threading on the MCX is a fantastically easy and secure way to mount a can. Sigs new cans, CGS cans and some Q cans all come with this taper, and you can buy aftermarket adaptors to convert hub compatible cans to use the tapered direct thread.

The MCX can be a little gassy for a piston gun as well. Not a huge issue, but I do get more gas to the face with these guns than I do with other piston set ups.

Now that I've addressed the negatives....My MCXs are probably my favorite rifles. Incredibly adaptable, can completely change handguard, buttstock, barrel lengths, switch between 5.56 and 300blk all with one T27 torx bit and a torque wrench. I've run my main MCX as a 16" 5.56 at a run and gun, as a 5" 300blk pdw to travel with and everything in between.

Current set ups:



Top is 5" 300blk with canebreak SD handguard and CGS Hyperion K direct threaded.
Bottom is 6.75" 300blk with Virtus SD handguard and CGS Hyperion direct threaded.

I've also used a standard rattler upper and handguard on the virtus when traveling. Take the can off and it can fit into a backpack and not raise any eyebrows as "that guy is carrying a rifle" when checking in and out of hotels on the road.



I would absolutely get back into the MCX platform knowing what I know now. It's probably the best way to do 300blk stuff, IMO.

MCX is a great one too. I have enjoyed shooting my Spear LT. I think I'll probably buy the Rattler next, or Boombox if that ever comes out.