5.56 vs .300blk

[Justin///M]

This isn't meant to be a 9mm vs .45 type of thread. I'll explain my question below.

My main two rifles are a Sig MCX .300blk suppressed (or not) SBR, and I have a Sig MCX 16" 5.56 rifle. All accessories match between both for consistency. I have the suppressed .300blk SBR for home defense. Yes, I know we can argue about a a subsonic .300blk effectiveness not being much greater than a 9mm, but that's not the point of this post and my question.

I keep the 5.56 rifle ready for everything outside of home defense.

My question is in regards to supersonic .300blk vs 5.56 as a "main rifle" from a ballistics perspective, if that makes sense. I'm wondering why my .300blk rifle wouldn't be my go to for everything. I have mags of supers and subs loaded up ready to go. Without the suppressor, the .300blk has a 9" barrel.

I'm not that educated on .300blk which is the point of this thread. I'm doing some reading and digging as I speak, but I know there's much more knowledgeable people here and would appreciate their insights.

Thanks!

[WoollyPullover]

I*m no expert but my understanding is 300blk won*t have the range like 5.56.

Also switching from subs to supers may be tricky to find a zero that works for both. The Eotech 300 seems like a nice solution for this.

I*m following so I might get edumacated as well.

[mountaineer1673]

i have the Eotech 300 black out. like it a lot - has different zeros for sub & sup. have had it for a year or so and it hasn't done anything odd or lost its zero.

MAC has some youtube videos with the 300AAC: https://www.youtube.com/watch?v=rTxhMFqzqV0

he did a good one with 300 vs level ii body armor as well.

[340M&P]

Depends on what you mean by "main rifle"

300BLK is fine for out to 300, past that it's dropping off much faster than 5.56

I've used 300BLK supers for deer the past few years and have not had any issues with stopping them. Admittedly my furthest shot was about 100 yards, the closest was 25 feet.

As a side note, I have a suppressed 45acp AR for the home defense roll for similar reasons. I have a 5.56mm pistol I could use for "everything else" but since I live where 50 yards is about as far as you can see/shoot, the 45 will do just fine.

[wanneroo]

Here in PA, where can you get into a firefight past 100 yards?

I don't have any 5.56 guns at all, although I imagine I probably will at some point, just for collecting purposes like the Steyr AUG or a Galil.

There are a lot of supersonic low 100-140 grain 308 bullets for 300 Blackout one can pick from. I am doing a lot of experimenting with them and probably will for a long time going forward. I can't imagine one would enjoy getting hit with a Hornady 125g SST at 2200 FPS.

I'm even looking at going bigger now to 450 Bush or 50 Beowulf or something similar.

[zachomega]

Under normal circumstances, cost and availability might be good reasons. I don't know the cost of 300 but before 2020, the cost of 5.56/.223 was pretty low and it was available everywhere. Being able to shoot more counts for something.

-Zach

[WoollyPullover]

I can't imagine one would enjoy getting hit with a Hornady 125g SST at 2200 FPS.

This is what I keep loaded in the bedside flashlight.

[85MikeTPI]

5.56 NATO is to wound more than kill, slows down the enemy

[ExFlyinguy]

Disregarding sub-sonic ammo, IMHO, inch for inch(Barrel length) the .300 hits harder than 5.56. Can that even be disputed? It may drop more at further distances, but I don't think that is relevant to OP's question?

Also imho, subs have no place in My SD uses

[Justin///M]

Thanks for all the input. I agree with those that talk about sub 100 yard engagements. When I think of defending my property, that's me. That's why I have MROs on all of my rifles. I'm not looking to reach out and touch someone. Also, with my MRO, I have had no problem with either the subs or supers I currently have with the suppressor on as far as zero goes. However, that's something I should do more experimenting with, such as suppressor off for the supers, etc.

Cost and availability is def a good concern, but prepanic, I did manage to stack my 300 deep to equal and soon surpass my 5.56.