Sig MCX-Regulator, Thoughts?

[socal m1 shooter]

As you might guess from my handle, I am kind of a refusenik when it comes to the AR platform. Walnut and steel, I'm good with it, I like it. Say what you will, but I saw something (Officer Gregg in a couple of different videos touting the Fightlite SCR) a couple of years ago and thought "maybe someday..."

I don't shoot as much as I once did and so I don't bother to keep up much with the latest and greatest, but recently I saw that Sig Sauer has a comparable CA-legal AR platform (MCX Regulator) and I was considering a purchase of one or the other.

Unfortunately as a family member used to say, I don't know sheeeeeeeeeeit from shinola about the AR platform, and figured maybe it would be OK to ask the CG brain trust for their thoughts.

I saw a couple of Sig MCX Regulator for sale posts here, and I did look at a couple LGSs to see if anyone had one in stock, without success.

If any of you knowledgeable AR platform people would care to comment, I would appreciate reading what you have to say.

[k1dude]

They're priced absurdly for a very large, heavy, and unwieldy rifle.

[turbolarry]

Ooooo.....
You're not kidding about the price. $1600 if you can find the right deal?
I would have to pass on that. I'd read up on everything I could about the AR platform and build my own, but that's just me.
Warning; The rabbit hole is deep...

https://www.ar15.com/guides/files/articles/primer/index.html?gid=195

[walmart_ar15]

They're priced absurdly for a very large, heavy, and unwieldy rifle.

That pretty much sums it up. Heck, I got one and it matches the quote very well. It's not just the weight, the balance is just off.

If you want a standard comb stock AR type of rifle, the CMMG version is better, or the Foxtrot Mike's Ranch Rifle, or the original Fightlite SCR, they are better considering weight, balance, and portability. (and price)

Buying a Regulator is really just buying the SIG MCX upper, that comes with a comb stock as an accessory.

I took my Regulator apart and match the lower with the FMP's upper and make the rifle more balanced and much more user friendly. I took the MCX upper match it up with an AR lower and now it functions like what it should.

So if you are thinking of getting a SIG MCX, this maybe a cheaper option. But if you are looking for a comb stock AR, you should look somewhere else.

[socal m1 shooter]

walmart_ar15, that is a very helpful reply. Much appreciated.

[k1dude]

Of what's available now, the Fightlite SCR and FM Ranch Rifle are your best bets simply because they're light and handy like an AR. The CMMG is like the Sig, very heavy and expensive. The problem with Fightlite is they're very difficult to find in-stock and are extremely unresponsive when it comes to customer service.

So if I were to buy personally, I'd like try the Foxtrot Mike FM Ranch Rifle. But, I already have an SCR that I bought back when they were the only game in town. I like the SCR the most because you can put any AR upper of your choice on the lower. The FM doesn't have a rear charging handle or buffer, so you have to use a side charging FM upper. However, some consider a non-reciprocating side-charging upper to be a superior beneficial feature over an AR with a rear charging handle and buffer. It's personal preference. As with all FM products, their Ranch Rifle is priced nicely.

Happy shopping.

[Capybara]

My vote is to simply assemble your own AR. Its addictive, fun, and you will literally know your rifle from the inside out, how it works, why it works or doesn't work. It will save you some money you can put into an optic or ammo. It will also make you appreciate the mechanical genius of the design and platform. I bought my first AR, a Windham Weaponry and its been a great rifle for years but since buying that I have assembled several others. If you want to own something high end like a Daniels, CMMG, I would buy a lower, assemble your lower and then just buy the higher end upper off the shelf. Or a few of them in different calibers and barrel lengths.

Also, I highly recommended building an A2 platform AR. I love the 20" barrel, fixed stock, irons sights, it's what the AR is designed to be. Not everyone needs or wants a 16" M4 carbine profile AR. We all have one or more but I enjoy shooting my A2 profile AR a lot more these days. Personally, I see almost zero reason for the average recreational shooter to buy an expensive AR, they are really not that much different or better than a lower end self assembled AR. IMHO, unless you are staking your life on it or working as a military contractor or something critical, expensive ARs just aren't worth the bucks. Inexpensive ARs are great these days, two of my most loved are cheap PSA builds with a cheap Anderson lower I bought years ago on sale for $20 at a gun store opening, they're great rifles, reliable, 1.2-1.5 MOA, look good and work well.

[gabe123]

Sig is not an AR platform rifle. The MCX upper can be fitted on a AR lower but it doesn't make use of the buffer tube. You cannot use MCX lower with an AR upper. If you are looking for an AR platform rifle, look somewhere else. I was once toying with the idea of getting a Regulator because of the rifle grip. It is one solid choice if you want a featureless rifle. The shotgun grip feels much better than fins. I can use regular mag release button. But like someone else said, it is big and long, and heavy. It just didn't feel right.

[socal m1 shooter]

In case someone else may be interested, here is what I am finding in a nutshell.

Brand	Cost (complete rifle)	Cost (Lower only)	Operation	DI/Piston	Charging	Notes
FM	$1200	< $499	Bufferless	DI	Left side	All in-stock = .223 Wylde, closed ecosystem?
Fightlite	$1300	$699	Buffer tube	Both possible	Left & top possible	Compatible with USGI uppers
CMMG	$1900	$449	Bufferless	DI	Left side	Closed ecosystem?
Sig	$3000	N/A	Bufferless	Piston	Top	Expen$ive

Regarding Foxtrot Mike, all the complete, in-stock rifles on their site seem to be this .223 Wylde caliber, which I am not interested in. The page for the one lower they have in stock right now plainly states: "Compatible with BRN-180 and our Bufferless Mike-15 Gen 2 upper receivers, available here in our store." I'm guessing that means, it works with our uppers but (probably?) not others. Confirm or deny?

The FightLite can presumably be made to work with any USGI-compatible upper, including side-charging piston-operated, should one happen to choose such as that. I think I am leaning toward side-charging 'cause middle-aged eyes may work more better with optics.

The page for the CMMG lower plainly states "NOTE: Br4 lowers are only designed for use with DISSENT Mk4 Upper Groups." So, again, that means I can't drop my Sig MCX-Regulator upper into that lower and expect it to work?

[k1dude]

,223 Wylde is my preferred chambering. Why do you have a problem with it?

The BRN-180 is made for Brownells by FM.

[tacticalcity]

I like the standard Sig MCX LT, it's pretty sexy and an interesting rifle with an interesting pedigree. The regulator version is just too ugly for me. The things we have to do to perfectly good rifles in order to comply with California's absurd laws is well, absurd. For an insane amount of money, companies like Solar Tactical can get you a legit Sig MCX LT with a fin grip instead. You could also use a middle man company to assist with this. I believe there are one or two advertising in the marketplace under the Commercial section.

[socal m1 shooter]

,223 Wylde is my preferred chambering. Why do you have a problem with it?

In my ignorance I assumed it was a new cartridge, not a chamber profile. The gun industry is a bit like the bicycle industry and the cigar industry in that they seemingly come up with new things (new cartridges, new wheel standards, new cigar brands) which are basically the same-old same-old, just repackaged. I appreciate your question.

So what about the ecosystems being closed? How closed is closed? For example, if someone got a wild hair and wanted to put the upper from a Sig MCX Regulator on a FightLite SCR lower, no can do?

I shot some finned grips that someone I know has and I greatly disliked it. So to me the conventional comb stock seems to be the lesser of evils.

[walmart_ar15]

It all boils down to the upper design. MCX recoil system has a higher profile than the normal AR upper receiver. Thus, all MCX lower receivers are taller where the rear charging handle sits. So normal AR upper with rear charging handle profile will not work with MCX lower. This means any buffer-less upper designed to fit the normal AR lower will not work unless the charging handle is on the side.

Sig makes an adaptor to mate their MCX upper to the standard AR lower. Standard AR LPK works fine.

Brownell BRN180 will work with MCX lower but with an ugly gap at the location mentioned above. FM upper will only work if its recoil rod and stop are modified or it will not work. I have no experience with CMMGs upper.

I got my Regulator on sale $1400. It's basically cheaper than buying the MCX upper alone. So, I spent $400 for the FM upper, put in some elbow grease and I got a SIG/FM hybrid Ranch rifle that is close to Fight lite SCR weight with the Magpul stock!

Bought myself the MCX to AR adaptor (careful use only the adaptor from SIG, aftermarkets are not real adaptor regardless of what they call it) and built an MCX.

So about two grand I got a Ranch Rifle and MCX.

Not all AR upper will work with SCR lower. It is designed to take all DI type of upper with its own proprietary bolt carrier that works with its recoil spring inside the stock (mouse tail). Buffer less upper will probably work fine, but any piston upper that uses buffer tube will not work due to the bolt carrier.

As for putting MCX upper on SCR, probably not a good idea. The recoil spring is captured inside the receiver once it is closed, but barely. It is the reason SIG offer the adaptor for AR receivers (of course won't work for SCR).

[shooter556]

Maybe you should just give the AR platform a try. Build a nice entry featurless AR and see how you like it. Will be cheaper than any of the ranch rifles and it will work just fine. Don't forget the 11% tax will be applied to the entire ranch rifle vs just the stripped lower on your AR build.

[Fnfan]

Personally I would get an M1A or a Mini 14