Currently I’ve got a few PCCs that are wearing suppressors for nightstand duty.  My usual go-to is in .45ACP but I occasionally opt for a 9mm.

I’ve got an unused 7.62 suppressor and was considering buying a 300AAC upper and using that for household nighttime duties instead of one of the PCCs.  But then I got to thinking about whether there would really be any benefit to using a subsonic 300 over the .45.  Or even over the 9mm??

Certainly it’s always nice to have another option but I’ve been on kind of a roll lately to reduce my collection of unused guns.

Thoughts from the masses here?

I don't do suppressors, which is why I have had an AR-9 with sub 147's for my nighttime gun.  I recently picked up a CMMG RDB bolt/barrel in 45 ACP that I have built up for that purpose from now on.  This is purely for the possibility that I may not have ear pro in at the time of need.  There are some pretty gnarly 300 BLK sub's, expansion wise, but expansion comes at the expense of penetration so there is a trade-off.  I feel pretty comfortable with a stick of 230 JHP's @ 1K'ish fps.  Even if I suppressed, prob would feel the same.

Unused 7.62 suppressor? Build a 300 just to try it at least. You can pick up a cheap barrel for $100 and swap it out in an unused AR

I only recently started buying suppressors. Until I received my first approval I was relying on 230gn .45 about 99% of the time for nightstand duty. But after buying my first suppressor I’ve been on a buying frenzy so that nothing I’ll ever have to shoot inside will be unsuppressed. I keep reading about the 300AAC as being the best thing since string cheese for running suppressed.  But considering that I’m well past the point in my life where I’ll consider chasing a threat to maintain engagement my longest shots will probably be no more than 50 feet. As much as I want to talk myself into a 300 upper I’m hoping someone here can tell me that I’d just be wasting money by doing so.

a 7-9" 300BO is way more betterer than .45ACP

A) You get to use standard AR15 BCG and magazines and lower.  Blowback AR15s are gross.

B) But for HD, just use supersonic 110gr TTSX/Sabre/Varmageddon ... the extra noise is not a big deal with the suppressor and you get rifle power.

C) Subsonic .300blk will be quieter than suppressed .45ACP, both using full size cans

D) Even if you want subsonic .300blk for HD, the segmented controlled subsonic .300BLK has some crazy expansion

E) Subsonic FMJ .300BLK has some pretty great ballistics compared to 9mm or .45acp ... still carrying most of it's energy out to 200+ yards and hits aren't that hard with a .300BDC reticle.

That’s what I was looking for. Thank you. It’s been too long since I really looked into ballistics.  Long before 300Blk even existed.

Thank you.

Still hoping for more data/opinions….

As I live in an urban dwelling, the use of any firearm for home defense would be fool hardy at best, so I have no personal experience.  That said, you may wish to consider the "ARFCOM Answer - Get Both".  The second being for back up, use by a second defender, more choice of ammo if SHTF, etc.

Best of luck, MHO, YMMV, etc.  Be well.

Certainly I was expecting the “buy both” response sooner than later.  I’ve REALLY been on a roll lately to rid myself of extraneous weapons. Is there such a thing?  I think, yes, when I peruse my collection and find five of the exact same gun or maybe just a few in calibers I’ll likely never shoot.

For SHTF I’m happy with any of my too-many 5.56 variants.  I’m living in an area where I’m not (generally) having to worry about taking out any neighbors should I manage to pierce an exterior wall.  And all of my spare rooms contain nothing living.

I’m heading out to shop at my LGS in a few minutes.  I’m pretty sure that a 300 is in my immediate future. I’m NOT sure, however, if that’ll end up being an expensive complete gun or merely an inexpensive (maybe PSA?) upper to throw onto an existing lower.

Please keep the opinions & suggestions coming.  I do better when under the influence of those more knowledgeable than myself.

Use supers and it makes sense.

.300BLK subs are extremely niche and make sense in very limited circumstances and I’m of the opinion that civilian realm HD is not one of them.

I will mention that my goto HD gun is an integrally suppressed 45acp.  Direct blowback.  But, not your run of the mill suppressor or blowback system.  It's nothing short of amazing and I like the performance of ACP more than 308 pills traveling subsonic speed.  Unless you're using "specialty" bullets in blk, about the best you can hope for with 300 blk subs is a deformed tip.  Here's some 308 nosler (blk) bullets that I've recovered from the berm.

(like this:


And this is one of Lehigh's max expansion pills.  There's no gaurantees that they're going to open up either.


Those aren't really all that impressive performance.  Not sure the distance those were fired, but they'll be within 50 yards.  Because I don't shoot subs more than that.  I could, but where I live and the terrain, you seldom get a 100 yard shot, much less longer.  So, again, those pictures above would've been within 50 yards.

I have some pictures somewhere while using speer 230 grainers that expanded out to nearly 3/4" diameter while retaining more than 94% of it's original weight.  That's pretty good.  And if you want more penetration, use jacketed flat tip 230's.  They poke nice round holes a lot deeper than HP's.  It all depends on what you want to do with them.

With that said, I've tested both calibers enough to know that my ACP is way more quiet than my 300 blk integrally suppressed gun.  And equally as reliable.  Plus, you never have to worry about grabbing a mag full of 223 and sticking in your 45acp lower either.  (don't laugh, there has been folks who have put wrong mags or bullets in 300blk ARs).  I even specifically use tan Lancer mags only for my blk upper to avoid that.

There will probably be folks who would point out energy ratings of blk and range, etc, but I concentrate more on how the bullets perform at the distances that I would be using them because at the end of the day, 230 gr 45 and 220 gr blk are going to be similar weight and velocity and ft lbs on target, but the ACP was designed for those velocities, whereas the blk was forced to deal with those velocities while using heavy 308 bullets that were designed to be fired at supersonic speed.  And lets' face it, anyone shooting long distances with subsonics are probably not going to be doing very well with them.

Yes, there are some 300blk bullets that will mushroom out and work better at subsonic velocities, but remember what I said earlier.  Unless you're using specialty bullets, you shouldn't expect that they will.  My experience says otherwise.  

It took me years to finally build a blk because robert silvers/AAC debacles about it turned me against it almost from day one.  And after I finally did build one, I quickly found out that it mostly just sucked.  At least in subsonic form.  Sounded about like garbage can lids banging together.  Poor downrange performance.  There's just much better things out there.  9x39 is even a much better performer for that matter.  But, is probably starting to get off subject.


I'll also say, if you go with 45acp suppressed, I would recommend a carbine over a pistol.  Plus, you could store it with wire pulling gel in the can and run it wet so it'll be a little more quiet too if you were forced to fire it indoors.  Reason I say that, many commercial 45acp cans aren't all that wonderful sounding either.  You asked honest questions, so I gave you some honest insight based on my experiences to maybe help you make a good decision of what may work well for you.

Supers are the way to go for HD.  110gr Tac-tx (or 110gr V-max/Vamrageddon is you prefer fragmentation) are proven, especially if you have a can.

If strictly subs, indoors only, it is hard to make a case for 300blk over 45 because the best expanding ammo is expensive in 300blk.   Hornady 190's are somewhat affordable, but would be put to shame by .45.  

A new kid on the block is PSA/AAC expanding ballistic tipped 220gr for 300blk, but I have not seen any gel shots on it.

Yea, the only thing that gives the edge to 300 BLK is the ability to shoot both super's and sub's.  If you remove super's from the equation it is 45 ACP all day along and twice on Sunday, IMO.

.300BO has:
Quieter suppression
capacity
reliability
range (subs and supers)
supers defeat soft armor
subs can have more expansion
milpec parts availability (standard receiver, BCGs, mags, ...)


.45ACP's only advantage is that it's cheaper.  

If the metric that you're going to base your home defense caliber selection on is "it's cheaper" ... then, go for it.  Hey, I hear you can get a whole box of .22LR for $5

LOL, 200-220gr subsonics already have projectile lengths that dwarf the widest expansions of the best 45ACP JHP.

147 jhp out of a cz scorpion. Dot, flashlight, no can.

I would be curious how a poly coated 220 gr lead flat point 300 bo would perform for home defense. It’s definitely gonna break any bones it hits.

Okay, I'll play:

.300BO has:
Quieter suppression - by how many db?  2 maybe 3?  It's a wash
capacity - if it takes more than 5, you suck / jk - advantage 300
reliability - meh, both my 9 and 45 have been 100% reliable, as has my 300 BLK (yes, I have one) It's a wash
range (subs and supers) - we're talking about indoors personal/home defense, not applicable
supers defeat soft armor - you must live in a tough neighborhood if perps are crawling through your doggie door in class 3, not applicable
subs can have more expansion - a 30 caliber bullet has to expand 50% before it gets to the point where 45 begins, advantage 45
milpec parts availability (standard receiver, BCGs, mags, ...) - my PCC's use standard uppers and p-mags and this is the 21st century so meh, It's a wash


.45ACP's only advantage is that it's cheaper. - the reaction of 1/2" thick, 10" hanging AR-500 plates, may indicate otherwise

If the metric that you're going to base your home defense caliber selection on is "it's cheaper" ... then, go for it.  Hey, I hear you can get a whole box of .22LR for $5 - people aren't hard to kill

Can you describe/post pics of your 45 setup? What mags are used?

I haven't paid much attention to more recent developments in pistol-caliber AR's. Last ones I gave any thought to were Cav Arms and CNC Guns grease gun lowers.

Thanks

I was looking for a 16" for this build because of the brace BS that was going down at the time, but an 8" RDB bolt/barrel combo popped up for sale so I went with it.  I needed a different plan with the short tube and got an MP-5 vision in my head.  Everybody who sees it loves it, and loves shooting it as well.  Very little recoil.



I wanted to use a standard AR-15 lower so I began to work on magazine possibilities.  I have a pile of p-mags so I reworked a 9mm insert til I could get a 1.25" length cartridge to fit.  Runs great but capacity tops out @ about 14/15 rounds.



I am going to work on an insert for metal Grendel mags as they have more internal volume.  My focus was just to build an AR that could run 45 ACP, and that box is checked.  Now to work on capacity.

That's awesome, but a bit more of a "project" than I want.

That's why I gave up on the whole 45/10mm grease gun mag projects I started 15+ years ago.

I'm too stupid to even visualize how you modified the mags.

Do you use different mag springs and cut back the folowers?

As others have said, leave subsonic to the pistols and range toys. For HD, .300 Supersonic is great ballistics in a short and handy package, with less recoil than a PCC.

I hope some of these PCCs run reliably, but I've never seen it. I've seen probably 10 of them in matches, and I've never seen one shoot a match without a malfunction, usually more than one. The least reliable gun I own is a CMMG Banshee PCC in .45. The accuracy is trash too. Worthless guns IMO.

Yeah, I don't get it either. 110 gr black tips vs any 45 hollowpoint? Why?

These inserts actually utilize the mag spring and floor plate of the p-mag, but as you can see, the feed tray and follower are unique.

The goal was to have a universal insert for 9/10/40/45, but the internal volume restraints of the p-mag make the fatter cartridges less attractive.

Dead is dead, how they get dead isn't all that critical, and people aren't hard to kill.  45 is a little easier on the senses

Oh, and bigger is always better

Well, where I am, my sheriff has let the people know  they have encountered "international" (ie. Venezuelan/Central American) burglery crews with wifi and cellular jammers. To assume they don't have soft armor also, to me, is silly.

I did switch my HD gun from 10.5" 5.56 with a K-can to a 9" 300BLK with a Razor762, which is about 1.5" shorter overall, but less muzzle blast.

Call me chickenshit, but if I am shooting at someone's sternum, I want them down, and staying down.

And, sincerely, I love gun projects and fun stuff, but if I have to shoot someone in my house, I don't want to be using a kit gun.

As always, mission dictates gear.

Yep, but now you have me looking at a B&T APC 45 & suppressor.

Bastard.

Anything to help a brother out...

One of them penetrates pistol soft body armor (suppressed subsonic), one does not.

That’s all I needed to know relative to my home defense decision.

I have yet to see a gel test on the AAC/Sabre 220 ballistic tips.   I really do wonder how those perform against level II armor and if they expand or not.

The data shows otherwise.

Statistically, the loser of a pistol gunfight typically survives.

The guys shot with rifles tend to die a lot more often.

True, but we are talking subsonic 300 blk vs 45 acp here so you don't have the velocity advantage of a typical rifle.

In the case of subsonic, I agree... It's equally as useless and not up to the task of self defense as pistol rounds. I can't fathom why anyone would choose either in a situation where a rifle is just as available or convenient.

on related note, if you are going subsonic, be sure the ammo works with your weapon and suppressor. In some cases you can have FTF's with subsonic ammo, at least I do and I test my ammo brand and type before committing to it.

Other than "i want to" I'm not really clear why one would go from a 10.5 5.56 to a 9" 300 if we are sticking to supers. Sure, blast, but I'd imagine suppressed indoors they are still both pretty blasty.

As cool as 300 is, it's just expensive in every way. I'm poor, so I don't see a return on investment and I'll stick to my 10.5 5.56.

All things equal, the 300 will be way less blasty.  I recall the member here that was in a shootout with a 10.5 (unsuppressed), he is now permanently deaf in one ear and that was outside.

That said, 300 is a bit of a niche round and fucking expensive for sure.  If the 10.5 works for you more power to you!

My HD gun is a 300blk, silenced, with supers.

Mostly it had to do with the fact of already having both uppers, and now trying to downsize my collection of guns/parts (which is why I had to slap myself for thinking about getting into a new .45 ).

I've being selling stuff off to get from around 15 AR's to 6 or 7. I've settled on 3 5.56 (11.5, 14.5, and 16"), the one .300BLK, and 2 12.5" 6.8 (1 standard AR & 1 Six8 receiver set.)

I've since sold off the 10.5 5.56 upper and will be using its registered lower with the .300.

I can think of multiple reasons.
*My 9" 300blk has less blast, flash, and gas, and runs less harsh than my 10.5" 5.56.

*My 9" 300blk is obviously 1.5"'s shorter than my 10.5" 5.56.

*My 9" 300blk shooting 110gr Tac-tx or 110gr Vmax/Varmageddon/Sabre delivers a bigger bullet with more *energy than a 10.5" 5.56 load.  (*Assuming like bullets types for an apples to apples "energy" comparison being that energy does not wound).  
Example:
Any 110gr round doing a very moderate 2175 fps out of a 9" barrel = 1156 ft.lb of energy.    
To equal that level energy, a 55gr 5.56 round would have to be doing exactly 3077 fps (1156 ft.lb).
OR
a 77gr 5.56 round would have to be doing exactly 2600 fps (1156 ft.lb).

Those are closing in on 14.5" to 16" 5.56 barrel numbers as there are no 5.56 loads that can achieve those velocities from a 10.5" barrel.  That is basically what 6MAX is doing from a 10.5".  

Ammo cost used to be a big concern, but the rise in ammo prices have impacted 5.56 (and 7.62x39) more than 300blk.  So while still more expensive, the gap isn't as big as it used to be pre-Covid.  PSA/AAC/Sabre is really helping on that front as well.  The AAC V-max and Black-tips rounds are about $0.65-$0.75 a shot.  They are both currently $0.65 a round (Daily Deal) as I type this:  https://palmettostatearmory.com/300-blackout-ammo.html

Velocity vids for that ammo:

PSA/AAC 110g Sabre black-tip out of an 8.5" barrel (2164 fps), and a 16" barrel (2446 fps).


PSA/AAC 110gr Vmax out of a 7.5" barrel (2064 fps) and 10.5" barrel (2256 fps).  


Cross contamination of ammo can always be a big concern, but ballistically speaking, there really ISN'T a reason to NOT switch outside of "I don't want to" (which is completely fine as well).

7.5 or 8" .300 is significantly ballistically superior and 2.5 to 3" shorter.

There's nothing wrong with a mk18 clone for HD, but the .300 has a slight edge in performance. If cost is a huge concern, then yeah I can see sticking with the 5.56.

As usual the best answer is get both. Volume train with the 5.56, and use the .300 when it matters.

Just to follow up on that Sabre Black tip ammo.  Same tester, same ammo type, only for 5.56.
55gr Black Tip is in stock and currently $0.52 a round (Daily deal).
https://palmettostatearmory.com/aac-sabre-blade-black-tip-5-56-nato-55-grain-20rd-box-ammunition.html

16"  
62gr = 2927 fps (1180 ft.lb)
75gr = 2701 fps (1215 ft.lb)



55gr  
10.5" = 2756 fps (928 ft.lb)
16" = 3072 fps (1153 ft.lb)


Remember, this exact same ammo chrono'd at 2164 fps out of an 8.5" 300blk (1144 ft.lb) and 2446 fps out of a 16" 300blk (1462 ft.lb).   Subs are neat, but this is why supers get the nod for HD.   What is always interesting is that the thread was about subs, and how we can take a single 8.5" 300blk and compare to a .45ACP sub-gun on one end, but also compare it to a Mk18 on the other end.  Yet no one would ever compare a .45acp sub-gun to a Mk18 because they are so completely and other worldly different.