Those two seem like the obvious choices for what I’m looking to get next: small, light, foldable for backpack or car, quiet with a suppressor.
Both are expensive. Both have non-standard components.

So it comes down to quality of (especially the proprietary) parts, customer service/availability of parts/longevity of the company. And handling etc.

Disclaimer: my wife has a few Sig products and they’re good - but I was also not blown away by some of the fit and finish and design choices in comparison to my German handguns. I have not handled it let alone shot the Rattler or Dissent.

What I like about the CMMG: looks, pricing (relatively speaking), placement of the charging handle (my go-to rifle remains my IWI Tavor which I much prefer over my AR15 - I still think the weight balance and charging handle placement on an AR are incredibly stupid).
But I’ve read here and elsewhere that there may be a few issues with the materials they select (grade of the aluminum, plastic parts and their placement) that may make the Sig a better deal.

What I like about the Sig: traditional company, now with a new but promising structure - been to the Sig headquarters and they are great people it seems and proud of their products. Good customer service (swapped out some parts no questions asked on my wife’s P320 that kept jamming). Good reviews, government contracts, parts available. Reviews claim higher accuracy (probably not important for this type of gun).
It is expensive though and it appears to have even more proprietary parts than the Dissent, doesn’t look as good (in that price range I feel it does matter, call me crazy), folding stock looks flimsy, charging handle placement relative to the Dissent.

I’ve got nothing but good things to say about my Rattler and the MCX platform in general.  There are a few legit complaints, like handguards that won’t hold zero with a LAM, but it’s a moot point with the Rattler.

Everything about the gun seems fairly robust, the bolt, carrier, op rod system, and piston/gas block are all pretty beefy.  Parts availability is good and most of your common wear components aren’t excessively expensive.  Some complain about the model revisions from the Legacy to Virtus and compatability between some components, but that list is small and there haven’t been a lot of recent changes.  FWIW, I’ve looked at the CMMG and there’s just nothing attractive to me.

If you don’t like the stock on the Rattler, there’s a plethora of options out there, although the standard minimalist stock isn’t flimsy at all.

My two:

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FPNI

Nothing against CMMG, i've never owned any of their products. However the RATTLER is specifically why I got into .300BO. It was impressive enough to justify buying a few VIRTUS guns.
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.300BO RATTLER  
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.300BO VIRTUS 9"
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5.56 VIRTUS 16"

Where are you in Ga? I’m in Marietta and have a rattler sbr and another pistol on an AR lower (for sale). They aren’t cheap but they run well and I trust one even after being in that cobb police shooting adventure last year. It was with me then, it’s with me now.

Not cheap, valid, but nothing else in the size that throws rifle rounds so well.

Proprietary parts? Yeah but there are a billion sig rifles now, even issued to .mil so parts will be around a while.

Only gripe I have is that they sometimes don’t like subs without a can. But that’s pointless anyway.

I'm not poor but I'm not rich either so I went with this to scratch that itch.

I wouldn’t say that’s really comparable given the barrel length.

PSA really needs to explore a 5”-6” barrel option for the JAKL.

I had a rattler.  I really liked the form factor.

It is kinda heavy for the size.  Not bad, but I'd generally expect very small guns to be lighter.
I was also getting lots of unburnt powder in the action.  I read here other people report the same thing.

I ended up switching to a 10.5 .300 AR.  That way I could run subs and supers with out having to mess with any gas settings.  It just works.

I was just pointing out that albeit a slightly longer barrel, there is another option for a somewhat compact folding stock 300BO which is much less expensive.

I’m in South Georgia.

Ok - I’m officially off and down a rabbit hole. Just discovered the assorted B&T options. APC300. Or maybe even something in 9mm.
I know - all quite different. But may all work for the original purpose. All expensive. All very nice it seems.

Sub gun sized .300BO > 9mm IMO.

Mo is Betta!

That would be a good comparison for something like the standard 9” 300BLK MCX, but the Rattler is fairly niche and in a class all its own IMO.  If you want something compact and concealable, there really is no substitute.

That said, if the OP is considering an APC300, then I’d say the JAKL should at least be considered.

This.  There’s a reason professional orgs with options have mostly phased out sub guns.

Update: decided on a 300 Blackout Rattler. Incoming.

Is there a sub forum for those? I’m sure I’ll have plenty of questions come up.

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I honestly believe you will not regret your decision. The Rattler is a fine weapon.

The same thing can be done on the Rattler by putting it in the + position for both supers and subs.

One of us! One of us! I tried a few different alternatives for a true travel backpack gun, I keep coming back to this.


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