9mm AR vs .300 Blackout

[alamo5000]

I have several irons in the fire and builds that I am planning out. Keep in mind I am talking about 'long term' here, IE the less cash I have the longer the term of the project

I have my franken 10/22 that I am building.
I have my Kidd Custom 10/22 that I am building.
I will buy a CMT .308 reciever set and do a build eventually with that.

One area that I am stuck on is the case to be made for a 'quiet' gun. Here is what I have in mind, but I would also like to get forum input in the specifics here.

The gun would be for 50 yards and in but there is a side by side case to be made for each.

Pros for .300BO
I already have an SBR'ed lower and a suppressor that can accommodate subsonic ammo.
It's a platform that has been proven consistent. (correct me if I am wrong)
I won't have to buy new mags etc etc.

Cons for .300 BO
Long term cost of shooting (extremely big consideration)
Going into yet another caliber for reloading
Probably will need certain types of powder for reloading whereas 9mm is much more diverse.
Questionable terminal ballistics (subsonic) for HD situations

Pros for a 9mm SBR
Cost of shooting is substantially less and there is a much wider and available selection of projectiles.
I can shoot supers or subs with my can no questions asked
MUCH easier to reload
I won't have any 'off caliber' stuff or even a new caliber to deal with. 9mm is 9mm regardless of the host and in a pinch I can buy off the shelf ammo almost anywhere.
I have a feeling that I would shoot a 9mm SBR way more than a .300BO for a number of reasons
For terminal ballistics I can buy off the shelf 124 or 147 grain hollow points and be good to go. While I never plan to shoot anyone ever it would be kind of nice to have those couple of 'special mags' ready to go.

Cons for a 9mm SBR
It would be a ground up build (for an AR)
I would need to SBR another lower
The system might still have kinks in it.

I am sure I have left off a whole lot out of this discussion but you get the idea. I have a feeling I would shoot the hell out a 9mm AR because of 1. the fun factor and 2. the cost of shooting is waaay lower.

Does the 9mm AR still have bugs in the system? How reliable is it? If there are kinks, what are they and how or has anyone overcame those things yet?

It would be a higher initial cost to get into a 9mm AR but after about 3 or 4 cases of ammo that would be MORE than made up for. I just think as a long term investment in shooting fun the 9mm AR will be a better value. In other words I am leaning that way but I would like to have a discussion on everything from terminal ballistics- to accuracy- to reliability- to reloading or whatever else there is between these two options.

There is also the option to get a Sig or a CZ and SBR it so let's throw that in the mix too.

What do you guys think? I am all ears for opinions. Once I decide on something it will help determine my future course of action.

[alamo5000]

[alamo5000]

I have also heard that CMT Tactical is going to make 9mm upper/lower sets so if anyone has info on that please post it up. (I am looking at you Uwone)

[alamo5000]

Basically I can easily envision myself forking out the dough (and borrowing a friend's progressive press) and churning the holy hell out of 9mm. For $1000 bucks or so I could easily keep a stash of 10,000 rounds of 9mm that I could use in a whole host of weapons. For 10,000 rounds of subsonic blackout... I don't think it would be anywhere near that cheap nor diverse.

Having guns out the wazoo but no ammo = no bueno.

To me it just makes way more sense to with a 9mm build or buy of some sort but I am leaning more towards the 9mm AR. At the same time I know next to nothing about 9mm AR's or what it takes to get into it or make it run or how finicky it will be.

[fledge]

If you live in a free state, I'd pick up the MPX and get the 9mm covered. Lots if good reports of the gen 2. I don't live in a free state, so I'm waiting for CMT to release theirs (they've been teasing since January!!!) so I can use my glock mags.

[Joelski]

Beg to differ. I have plenty of 9 mm pistols and feel a 9 mil AR would be a step down both in terms of fun and terminal ballistics. The 300 will edge the 9 in range, though they're both bullet drop champions, and the 300 would be quieter, with the appropriate can.

[Joelski]

Also, diversity of the 9 mm is not a con for the 300. That should go in your pro 9 mm column to keep your analysis objective.

[alamo5000]

If you live in a free state, I'd pick up the MPX and get the 9mm covered. Lots if good reports of the gen 2. I don't live in a free state, so I'm waiting for CMT to release theirs (they've been teasing since January!!!) so I can use my glock mags.

I am in Texas so I don't have to worry about that part of it. I absolutely love Sig pistols (although other stuff is growing on me too) but I have little to no experience with other products they offer.

I am extremely tempted (and have been for some time now) to jump on the MPX but in the back of my mind I am not sure if I would like the AR9 better.

It's really down to those two I guess. That said if I can customize a gun and build it from the ground up with generally generic parts that seems a bit more appealing than proprietary everything.

At the end of the day it's a tough choice, but I would want to make an educated choice and I don't know anything about what parts go into an AR9.

FWIW I like the Sig magazines a lot better though.

[alamo5000]

Beg to differ. I have plenty of 9 mm pistols and feel a 9 mil AR would be a step down both in terms of fun and terminal ballistics. The 300 will edge the 9 in range, though they're both bullet drop champions, and the 300 would be quieter, with the appropriate can.

Eventually (like way eventually) unless I win the lottery I will have a dedicated .30 cal can (mainly for the above mentioned .308 build) but also for any other long range guns I might get into. I am window shopping on some potential longer range bolt guns too. I guess I could slap that on a .300 BO but when that happens might be a while (1 or 2 years from now).

The only 9mm rifle I've ever shot was a friend's MP5. If I could afford one of those...holy sh** batman.... I would be on it like white on rice. Those 3 round bursts and full auto mag dumps are wood inspiring.

I've never shot a .300 blackout but at the end of the day cost to shoot it would still be substantially higher. I have also never shot an AR9 either but just logistically speaking 9mm seems to be winning out for what I am considering (once you put in all the factors).

[alamo5000]

Also, diversity of the 9 mm is not a con for the 300. That should go in your pro 9 mm column to keep your analysis objective.

Point taken.

We can put whatever we want in either column. That's what I am after... is feedback.

That said if the 9mm doesn't live up to what I am expecting out of it I could possibly speed up a .30 cal can purchase...

[BoilerUp]

First off, we all know the real question isn't "which?", but "which first?"



I got into the 300 BLK first, as I thought it would make a for a good home defense setup (SBR'd and suppressed). Given that you already have an SBR lower and a suppressor, this seems like the cheap and easy next step for you. While I still enjoy my 300 BLK pistol and still plan to SBR it and pick up a suppressor, I'm not quite as enamored with the round as I was when I first got into it, primarily for the reason you mentioned above: subsonic terminal ballistics. For defensive ammo, you are better off with supers, such as the Barnes TAC-TX, which negates part of the attractiveness of the caliber. I got into 6.8 SPC after the 300 BLK and if I'm going to have to run supers anyway, I'd rather have the 6.8 whenever I care about terminal performance. That said, the 300 is a softer shooting round, but my mental model for the BLK is basically that it is a magnum pistol caliber.

On the 9mm: I think a suppressed 9mm SBR is about the perfect home defense weapon and the MP5 reigned supreme in this category for decades. I was saving my pennies to buy one (well, a clone) until I saw Sig's announcement regarding the MPX. I waited patiently and kept saving my pennies and picked up a Gen2 recently. It's awesome. Same ergos and manual of arms as the AR so it's instantly familiar and my muscle memory applies. I love HK roller-locks, but I think Sig knocked it out of the park with the MPX and rendered the MP5 obsolete (although I still want one for the collection!). I considered an AR9, but you end up with a lot of proprietary choices and high end components are going to push you over $1,000 anyway. So, for the 9mm, I decided that a factory gun is probably the best course of action. Terminal performance of 147gr Gold Dots is pretty well documented.



Either is going to get the job done. The 300 BLK let's you easily build your own. It seems the AR world has turned its attention to 9mm lately and there is a lot of innovation happening there, but it seems even more confusing than the AR10/SR25 world. I'd suggest taking a hard look at the MPX if you choose to pursue a 9mm.

[alamo5000]

First off, we all know the real question isn't "which?", but "which first?"



I got into the 300 BLK first, as I thought it would make a for a good home defense setup (SBR'd and suppressed). Given that you already have an SBR lower and a suppressor, this seems like the cheap and easy next step for you. While I still enjoy my 300 BLK pistol and still plan to SBR it and pick up a suppressor, I'm not quite as enamored with the round as I was when I first got into it, primarily for the reason you mentioned above: subsonic terminal ballistics. For defensive ammo, you are better off with supers, such as the Barnes TAC-TX, which negates part of the attractiveness of the caliber. I got into 6.8 SPC after the 300 BLK and if I'm going to have to run supers anyway, I'd rather have the 6.8 whenever I care about terminal performance. That said, the 300 is a softer shooting round, but my mental model for the BLK is basically that it is a magnum pistol caliber.

On the 9mm: I think a suppressed 9mm SBR is about the perfect home defense weapon and the MP5 reigned supreme in this category for decades. I was saving my pennies to buy one (well, a clone) until I saw Sig's announcement regarding the MPX. I waited patiently and kept saving my pennies and picked up a Gen2 recently. It's awesome. Same ergos and manual of arms as the AR so it's instantly familiar and my muscle memory applies. I love HK roller-locks, but I think Sig knocked it out of the park with the MPX and rendered the MP5 obsolete (although I still want one for the collection!). I considered an AR9, but you end up with a lot of proprietary choices and high end components are going to push you over $1,000 anyway. So, for the 9mm, I decided that a factory gun is probably the best course of action. Terminal performance of 147gr Gold Dots is pretty well documented.



Either is going to get the job done. The 300 BLK let's you easily build your own. It seems the AR world has turned its attention to 9mm lately and there is a lot of innovation happening there, but it seems even more confusing than the AR10/SR25 world. I'd suggest taking a hard look at the MPX if you choose to pursue a 9mm.

Wow. Very Very interesting post. Thank you.

I considered an AR9, but you end up with a lot of proprietary choices and high end components are going to push you over $1,000 anyway. So, for the 9mm, I decided that a factory gun is probably the best course of action.

This is what I need to learn. How you figure you are going to have proprietary parts on an AR9? Such as?

As I said I am not very familiar with the AR9 and what all goes into the soup but I was thinking of it more in terms of modularity like a standard AR15.

Would you mind expanding a little bit about that point right there? Don't AR9's use a lot of standard AR15 parts? (Such as triggers or whatnot)...when we get into proprietary stuff what exactly are we talking about here?

[alamo5000]

First off, we all know the real question isn't "which?", but "which first?"

True! LOL!!!

That said I really am trying to become very judicious in my ammo control/supply situation. Having calibers out the ying yang makes life a pain in the ass sometimes.

Not saying that I won't ever expand into new calibers but for now I am trying to stock up and shoot within my budget.

I am going to take another look at that MPX and see what I can see as far as barrel length options and so forth. The last time I looked (online) the stocks were impossible to come by...and if I get one 90%+ chance it will be SBR'ed. I also want to see what my barrel length options are.

Depending on the realities of an AR9 the Sig definitely could find a home.

[BoilerUp]

I'm not an expert on the AR9, but I wouldn't assume you can swap / interchange uppers, lowers, and BCGs across the board. Maybe I'm wrong, but PSA has some warnings on their website. So, if I was going to build an AR-9, I'd probably get everything from the same manufacturer just to be sure.

Spare parts, including barrels, for the MPX are still pretty hard to come buy, but now you can get the 8" and 16" uppers as well as the standard and PDW stocks. I don't think the 4" barrels are available yet. Sig's getting stuff into the market, it's just slow. I've even seen MPX lower assemblies for sale on gunbroker, so you can break up your purchase. Personally, I want the 8" barrel with the carbine length handguard to shroud a suppressor. Some day.

[alamo5000]

I'm not an expert on the AR9, but I wouldn't assume you can swap / interchange uppers, lowers, and BCGs across the board. Maybe I'm wrong, but PSA has some warnings on their website. So, if I was going to build an AR-9, I'd probably get everything from the same manufacturer just to be sure.

Spare parts, including barrels, for the MPX are still pretty hard to come buy, but now you can get the 8" and 16" uppers as well as the standard and PDW stocks. I don't think the 4" barrels are available yet. Sig's getting stuff into the market, it's just slow. I've even seen MPX lower assemblies for sale on gunbroker, so you can break up your purchase. Personally, I want the 8" barrel with the carbine length handguard to shroud a suppressor. Some day.

If I was going with the MPX I would probably outfit it like this...(or have these options)

4" barrel and an optional 8" barrel, both with a 3 lug adapter.

I am not sure of the ID of the hand guard but from what I recall it's pretty wide. Hopefully I could recess my GA Revolution 9 under the rail at least some. Maybe an inch or so with the 8" barrel. In the K configuration the 8" barrel + can would be about 14" total. With a 4" barrel it would give me about 10"+ some.

I have no idea what my options are on handguard lengths or if there are any options at all.

I would have a VFG on there but I am unfamiliar with how attachments go onto the MPX handguard. If it's just screws that go in there I wonder if they would protrude far enough out to hit the suppressor at any point?

I would also have a light on there. I bought an Arisaka light for my current SBR and I love it. It's mounted at the 10:30 position and that is just about perfect for me.

As far as future stocks go (once the form 1 comes back) I might lean towards the pdw type but I would again have to go fondle one to figure it all out.

Also with the Sig could I drop in a new trigger? Say for example if I wanted to use a CMC or something?