.300BLK vs. 9mm PDW for Backpack Carry

[castrotikon]

I'd like something with a sub 8" barrel and folding stock ideally, I was originally leaning towards a 300BLK for performance but our president came out today and said a 9mm could blow the lungs out of the human body so I'm thinking maybe I should just stick to 9mm for cost effectiveness of ammo.

[thedonn007]

I think something like this would be cool to own. It would be really nice for someone to make an upper in 9mm that I can pin to my AR lower and fire it with the stock folded.

https://www.sigsauer.com/sig-mpx-k.html

[j-squared]

If you are also thinking of putting a suppressor on it, I think a gas operated system with lockup would make the 300BLK a slightly better choice, for flexibility.
But one can not ignore the ammunition savings of 9mm over 300BLK.

[Top]

I just finished this gun. I used a six inch barrel with an Omega 9k. With eforms being so fast I SBR'd the thing and am still waiting on the Law Tactical folder. Same thought process, something small that I am familiar with all of the controls and will fit into a back pack. I'm running 220 Sierra soft points and also keep 110 grain bullets for times when some extra pep is needed. This is also why I went 300 over the 9mm

[JohnS624]

Do you want a gun that will fit in a backpack or do you want a gun to carry while backpacking?

[pscipio03]

Or you can get a 45ACP SBR.
Very similar ballistics of a sub 300BLK but at a fraction of the cost. And since 45 is 99% of the time running under 1,100 fps, you’re not paying extra for subsonic ammo.
If you are set up to hand load 300, then run with that.
I’ve got a SBR 9, 300BLK, and 45ACP and I shoot the 45 more than the rest.

[BMT85]

My personal opinion, if you run a pistol cartridge, go with CMMG radial blowback. For what some are charging for straight blowback 9mm, just go CMMG radial. After that, if you reload, go 300blk. I am personally not a huge fan of 300blk, but I can reload 300blk cheap for plinking rounds and around $1 a round for premium subsonic and supersonic. Running a CBB bullet for sub or super will beat 9mm and 45 acp in performance.

Edit - I forgot to say, if you don’t reload, I would not suggest 300blk. Most of the ammo isn’t worth the price for performance. Just stick to pistol cartridges at that point, especially in a super short barrel.

[castrotikon]

I appreciate all the input but my post was mostly intended as a joke giving the Biden's comment lol.

That being said, I'm very close to pulling the trigger (pun intended) on a Sig MCX Rattler for a 300BLK backpack gun.