SO, the decision before me is whether to completely abandon the AR15 platform for the MCX platform. Why completely abandon? Well.... obviously because the COST of spare, replacement and upgrade PARTS for the MCX line precludes owning anything else for a person of my means... but also because OCD; All my everything has to match. My current setup should make this clear... Currently, my rig runs like so:

- Daniel Defense DDM4 V7P Law w/ Tailhook
- Daniel Defense DDM4 PDW complete Upper Reciever (which is actually the upper that gets used much more, since I tend to practice suppressed with .300blk subs)
- LOTS of upgrades and optics and bits of tactical plastic; Eotech EXPS optics, Trijicon Credo 1-4X scope, OTAL lasers, Unity, Radian, FCD etc etc.

This setup was hard to get my hands on.... and I only recently discovered why, but more on that below. I actually had a Sig Sauer MCX RATTLER which I really enjoyed shooting, but which I ultimately sold to fund the PDW upper, some glass, and an M1A SOCOM.... because I THOUGHT I had made my decision and was gonna stick with the AR platform. Then I finally figured out why, towards the end there, Daniel Defense Pistols and short uppers had become so hard to come by;

Daniel Defense is no longer going to be producing factory pistols, and MAY NOT be producing factory SBR's any more either. Uppers may continue to be available sporadically, but they're done with anything with a less than 14.5" barrel.

This was a rumor I'd heard several places, and was mostly confirmed by a call to DD customer service. Suddenly the complete PDW pistol, in any kind of good shape is selling for $2,500 and up used, the PDW upper is fetching $1,300 or even $1,700* on GB and the other pistols like the V7P are all selling for over $2k used. Even selling my rig for a very fair and not speculative price in today's market I could easily DOUBLE my money, and it would be enough to buy rig I thought I'd decided against; A Sig Sauer MCX RATTLER-LT .300blk + MCX SPEAR-LT 11.5" 5.56 Upper.

Now I'm no collector. I couldn't care less about the "value" of my DD stuff. The fact that it's now "rare" and will increasingly rare as time goes on holds no value for me. The only thing I'm concerned with is... if I sell this stuff in order to switch to the MCX line, I will probably never be able to replace it if I ever change my mind, or reach a point where I might easily afford to own BOTH. So this becomes an almost certainly PERMANENT decision which can't be undone. To make matters worse, I guy I know has suddenly shown up with THE EXACT SETUP I'M AFTER (RATTLER-LT and SPEAR-LT UPPER) brand new in box for an incredible price.

There are a number of benefits to switching to the MCX platform in my view. I remain convinced the MCX platform is both better suited to suppression and an overall "tougher", more rugged platform than just about any AR, excluding the very top-end stuff like LMT and KAC. Another great benefit of the MCX platform is, whatever ends up happening with this absurd Pistol Brace Rule nonsense, the MCX platform is well and truly a "Pistol" with no buffer tube and does not necessarily require any modifications or additions to comply with the rules no matter which way the final decision swings.

SO - knowing that I would in many ways PREFER the MCX setup (tougher platform, brace-law blind, better recoil, more suppressor-friendly & more compact) and due to market circumstances can now suddenly AFFORD to own it, should I sell off my hard-won DD rig to do so, with the knowledge that I will likely never be able to find and/or afford to replace this stuff ever again due those same circumstances and will also be giving up all the benefits that come with an AR (cheap, hi-quality and widely available parts, proven long-term reliability and most of all; the secure knowledge that the whole platform won't be suddenly REV II, GEN4'd out of existence and parts compatibility the way SIG frequently does)

I'd be very interested to hear from people who own or have previously owned BOTH platforms.

(if you had any doubt about the OCD thing at the beginning of this post, you don't now do you lol)

*if you doubt me, go have a look at completed auctions on gunbroker for anything DD Pistol... ESPECIALLY DD PDW model stuff. A used PDW upper with some very noticeable salt recently sold for over $1,700 and a complete PDW Pistol (with an Eotech XPS included) just sold for over $3,200.

The AR15 isn't going anywhere even if company XYZ decides to stop making parts.  What happens when Sig decides tomorrow to no longer support the MCX platform?

Yeah, that's pretty much the major consideration. Some people make the argument that now, since SIG has shipped so much of the "Spear" era stuff to Military end-users, that they would NEED to keep supporting it. The obvious answer to that argument is " Sig 556"

However for me, that's less a consideration. For example, before I had even completed my DD rig listed above I had collected:

- (2) Spare DD Bolts
- (2) Bolt Repair Kits
- (1) Complete spare BCG
- (1) DD Lower Parts Kit
- (1) Complete Pin & Spring kit
- Various assorted spare furniture

The only things on my list I haven't gotten yet are spare barrels for each. I would probably do the same thing with MCX spare parts if I went this way; just acquire as many spare parts as I could over the next year or so.

Sig drops product lines all the time.  AR has been around 60+ years.


You  don't have OCD (seriously,  look it up), but you might be a bit neurotic.  Still, plenty.of DD parts on the market.... and are you really shooting 20-40k rounds and shooting out barrels and bolts?

 

This shouldn't really be the thing we're focusing on here... but can't BOTH be true lol? Seriously tho... the way American Society has fetishized "victimhood" and made things like autism & PTSD into virtually elective lifestyle choices people can claim in pursuit of social kudos, positive reinforcement, and attention from strangers, I can see why you might say that.




Not this year I won't. Within the next 4 or 5 years? Absolutely I'll put 20k rds down the pipe. I went through 6k rds of various caliber in 2023 alone. I live out in the woods. My range is my 30+ acres of densely wooded mountains.  But the point is, this will be a semi-permanent decision. I won't be selling this stuff and buying new stuff anytime soon. A good example is my history with 1911s. It took me 4 years and who knows how much money and individual pistols to discover exactly what I like and didn't like in better 1911's. I now have three fully custom 1911s; an Officer, a Commander and a highly customized SA EMP4 CCC, and I've had no desire to sell the or trade up to anything else for years and years and will very likely keep them forever.

... And I have other reasons I consider very valid for keeping these spare parts on hand, but which tend to invite both criticism and all the wrong kinds of support when discussed on forums like this.

So why is DD discontinuing the shorter barrel lengths? That makes absolutely no sense seeing how popular 10.3” is.

If the MCX will be your primary setup make sure you are stocked up on spares …

Nothing beats an AR as a primary 5.56 gun … DD makes some of the best ARs and you are quite set.

But there is 100% nothing wrong with moving to a MCX platform. I did with the .308.

Not the mcx- 9.4% resulted in catastrophic failures with German police
And 66% failure rate in a recent Scottsdale police shooting

Wasn’t the Scottsdale incident related to a bad magazine and the gas setting was wrong? I don’t blame the MCX, that one is probably user error.

Was anything ever confirmed about that incident at all?
From the stoppages to the ammo to the bullets being stopped by the vest?
The last update on the thread was inconclusive, as I recall.

That’s why I’m no fan of 300BLK. 5.56 would have punched right through that vest.

Do you like the guns you have? Keep them and quit worrying about it. You will most likely always be able to AR parts. You don’t need DD parts there are lots of quality makers out there.

The MCX will be around for a while but if it goes dead you can get another AR.


You’re very much overthinking this.

If an AR15 is an option, the AR15 is the answer.

Personally, I reserve other designs for fulfilling requirements that the AR can't do or do well like barrels under 10", firing with folded stocks, different calibers, etc.

Sure, I have novelty collector rifles like a SCAR, ACR, AK, etc, but I'm under no illusion that they are better than an AR.

If you want to standardize on MCXs because you think they're cool then go for it, but there's no need to convince yourself that they're "better." Personally, I think it's a bad idea, but it doesn't matter what I nor anyone else thinks.

ETA: I own DD and have seen many of them in my courses. They are a good rifle but way over-hyped. You can easily replace them with ARs of similar or better quality/performance later if you change your mind about the MCX.

MCX is proprietary.

AR15 is basically open source, you've got at least a hundred different manufacturers to choose from for rifles or parts, and damned near every one of them is interchangeable. That won't change until the military completely discontinues use of the M4 in lieu of something else, and even then, the AR will soldier on. It's America's rifle.

After seeing another Sig AR15 commercial, I did have an odd thought... Why hasn't Sig tried making a DI/internal piston MCX upper? Be neat if they could offer a direct competitor to LMT's convertible MRP line of rifles, able to swap between piston and DI with just a bolt carrier and barrel assembly. There's obviously a market for a lightweight, folding AR, what with how popular the Law folding adapters are.

If I do this, and every decide to go back to AR15, it would be 100% LMT. I learned too late.

Interesting. After owning some LMTs since 2015, I wouldn't go that direction again, but I wouldn't dump the ones I have. I like their "militaryness" but don't actually use the monolithic upper's rigidity even though I have to carry it. LMT has bottom-tier CS and their post-pandemic pivot to KAC-like drop culture doesn't inspire confidence.

I actually had to go look up the article, instead of just drive-by statistics.
From ze German article:
So "allegedly", the barrels wore out faster. Uh-huh. Hardly catastrophic. I'd bet that either
1. improper cleaning chemicals/methods were used
2. a small batch missed nitriding or chroming.

The shootout-we still don't have facts. The officer that had to get out the passenger side could have partially pulled the charging handle back, pulling it out of battery. What I can see for certain is some kind of odd magazine extension. Some guy in GD claimed they were using supers, not subs. Who knows.

I would place the issues with the police shootout with:
1. Questionable mags/aftermarket (maybe they're great, I've never seen them)
2. Ammo issues (subs in general seem to be more picky)
3. User error (wrong gas setting/ammo selection compounding/cleaning)

All that said, I have spare bolts, recoil springs, firing pins, and a barrel clamp. Oh, and a few complete spare MCXs.

So the Germans claim to have issues with the MCX? That sounds very suspect to me and I’m sure HK had something to say about it.

Some in SOCOM are using the MCX platform and picking it over the HK416 and I haven’t heard of any issues with MCX’s failing.

I heard of tons of issues with parts longevity and breakages on both the USASOC and Navy side, but none of it's open source.

The Sig was runner up to the Geissele/Surefire rifle in the third party testing to replace the 416 in USASOC, but Geissele did something with pricing that bumped them. Apparently, the production Sigs exhibited a bunch of issues that weren't present in the test guns. Last I heard they were replacing a bunch of parts with titanium, but this was a while ago and I don't know how they worked out.

That’s news to me. Bottom line, firearms are machines and with any machine that’s put to heavy use, you will have breakages. Doesn’t matter what company they are, but Sig has always guaranteed the MCX platform to 20k before any parts need replacing. I hope that’s still the case, because I really love the Spear LT line.

I remember hearing about the swap from steel wear inserts to titanium ones, but I thought that was just to shave off another couple ounces.

I kinda doubt they're having more maintenance issues with the MCX than they do with basic 10.3" CQBR's. Even if barrels are wearing out at the same rate, which wouldn't surprise me with a constant, high tempo diet of M855A1, it allows for almost all maintenance to be done at the user level, which is a nice improvement for the folks that burn out barrels regularly. Bolts should last longer than standard M4 bolts, but again, M855A1 tends to shorten bolt life. That 20K round count figure is for commercial spec 5.56.

MCX might have some of the same issues the 416 has once you get some rounds through it, they've both got a higher cyclic rate than the AR15 to begin with, so erosion to the gas port exacerbates that issue. I could see that causing issues when coupled with 855A1, I'm not certain if Sig did anything to the military models to accommodate the accelerated wear over commercial ammunition.

That makes total sense. I heard that as well that titanium replaced the steel wear points to save on weight only.

Also, I think the only difference in Gov/ LE models are the chrome lined barrels and the finish is normally in black. I think everything else is the same.

Doubtful that DD will stop making SBRs. Lots of manufacturers stopped making pistols due to the brace issue, pistols were sitting around unsold all year because no one wanted them. You’re reading way too much into that.

This.

Their customer service is awful.  Absolutely awful.  Their guns are "good" but they're not exactly god tier.

Anyway back on topic.

You're shooting 6k rounds of rifle ammo a year yet you're thinking that you will only ever be able to afford to swap to another platform ONCE in your lifetime?  That's seriously dramatic but I don't know your finances so you're the only one that really knows if this is true.

What does the MCX do that the DD guns don't?  See if you can answer this question for yourself.

The MCX is not better than the AR15.  It has some "better" features but it's not better as a platform.

You could easily buy multiples of the AR15 wear parts for a third of the cost of most MCX parts and pieces.  You will also be able to walk into any gun store in the next 20-30 years pending some kind of massive ban and find AR15 parts.  You won't be able to do this for the MCX which means fronting the cost for barrels, bolts and other small wear items up front.  That's a giant up front cost that I think is hardly worth it.

I adore my MCX.  It's one of my favorite rifles and my current night time training gun.  I still question whether or not id grab it if the world were ending tomorrow.  I tend to think not.

This is has some interesting points but before I get there -

I have decided to keep my DD rig. I asked myself to really admit to myself what the motivating factors behind this were and, although there were several, and most have been stated here, at the bottom of it all was the simple 'Cool Factor' of the Rattler and the Rattler-LT. I don't even really LIKE the Spear-LT, I would only get that upper because, as I've said before, everything has to match in my world.

You made a point somewhere that seemed to say - if I can afford to run through that much ammo, I can surely afford to upgrade or switch up later. I have two responses to this; FIRST, I used to be in a band. I play electric bass. I was lucky enough to end up in one band that got an indie record deal and I spent two summers touring the USA and giving opening support to some of the bands I really idolized. But I was never a great bass player. I daresay I was GOOD, but I was never GREAT, nor even VERY GOOD. I sure had nice gear tho. I spent so much time, money, and effort finding THE PERFECT electric bass (if you think guns are expensive, go check out ALEMBIC BASSES... the cheap ones start around $14k)... finding THE PERFECT Tube Preamplifier, THE PERFECT Analog Compressor, and so on... I never had any time or will left for practice and developing myself as a musician. I don't do that anymore. I went through any number of 1911s before I figured out what I really liked, but at a certain point, I just stopped, and have stuck with what I have. I probably peeled something on the order of 10k rounds or more learning how to be capable (I wont say I'm 'proficient') with a pistol and if if I'm gonna get into AR15's I should spend most of my time, effort and money SHOOTING and taking classes.

SECOND;  Of course I will probably buy new stuff in the next ten years, this was more about making a commitment to a platform and learning that.

These aren't super complicated systems. The hard part is the skill building that can easily transfer between platforms as close as the MCX and AR.

Quite correct and well said.