Need Help In The 300 Blackout Area

T

timlab55

New member
I'm still wet behind the ears in this department of firearms. But I'm learning as I go. With so many items/terms out there, I need more help and I come here to get it. I currently have an AR15. Love it (what's not to like about it). It has a 16" barrel on it with a 1:7 twist rate <----see learning. When I fire the 5.56 rounds through it, it sounds like someone toss a can of hair spray into a fire. I'm sure everyone else around me really doesn't like that sound. Then my .223 also sounded like that until I put a Canooter Valve Suppressor on it and using .223 sub ammo, just a smooth as a baby bottom. The only problem I'm having is the cycling of the rounds with it. So after the reading I've done and everything, I might have to end up putting a 300 blackout upper on my AR 15 bottom. Now the store I use is Palmetto State Armory here in South Carolina. But when I go to their website and look at 300 blackout upper's, I see a ton of things that I don't understand. Here is the link for it: https://palmettostatearmory.com/ar-15/barreled-upper-assemblies/300-blackout-uppers.html
If someone could help me choose which upper I need I thank you.
Dan
 
The 300bo uppers should all work on your lower.

You just really need to decide on barrel length.

I would get a complete upper that has the BCG with it. The bolts from 5.56 will work, but I wouldn’t swap them between uppers.

A 300aac out of a 16 inch barrel is considerably quieter than .223 without a suppressor. It’s like a pistol cartridge out of a rifle.
 
just a thought timlab55; you are aware of the fact that one can put a pistol upper on a rifle lower and without jumping through all the government hoop you have an illegle "short barreled rifle" be aware of the laws before you buy something that may have hidden expense attached.
 
I thank you both for your answers and tib bit. However, I was hoping (without any problems) you could visit that link I included, and pick one for me so that I could order/get it. I have no clue what a pistol upper is as I'm sure in South Carolina we have no laws about doing this pistol upper. So I asked if someone could just go to the link and say okay "this guy is looking for a 16" barrel for a 300, with everything that is needed, this one will fit the bill.
Thank you in advance.
 
Ok. Im pretty deep into the 300blk. Subs, supers, bolt, semi, reloading and have built a number of AR’s in that caliber.

When i click on the link. The very first one would fit you requirements. Further down is one on sale ~$249

On your “Rifle” lower, legally you need a 16” or longer barrel. In 300blk a pistol length gas system is best (nothing to do with barrel length, gas system-pistol length). So start looking for those requirements. 16” barrel, pistol gas system.

I would agree with the above comment. Buy a complete upper and just swap them onto your lower.

A word of caution… be VERY cautious when swapping calibers. Make absolutely certain you use the correct ammo for the upper you are shooting. 300blk has been loaded into 5.56 chambers with catastrophic results.
 
Sharkbite- I like the way you explain things and very easy to understand. Now Sharkbite, what type of ammo would I use in this 300Blackout in the subsonic range? I'm not trying to be dumb, but I'm here on the Firing Line to learn. And why your at it, what is BTHP HP = Hollow Point, but I don't know what the BT stands for.

On a side note - Again as I've said in the past post, I'm still trying to get the AR to cycle with sub ammo. I'm just waiting for the light spring to come in, try it and see if that helps. If not then the next day I will order that upper half.
Thanks
 
Are you planning on suppressing your 300 BO? If using your current suppressor, please make sure it is compatible with a 308 bore. Unless someone has direct experience with the same model suppressor, again suggest asking the manufacturer directly

As others mentioned, if you go below 16 inch barrel length, you will need a proper Federal/State authorization.

BTHP likely means a boat tail hollow point.

Hornady makes expanding sub sonic 300 BO rounds
 
Later down the road I do plan on running a suppressor, and I found out that I can not use my current one. That is why I'm really hoping that this light spring for my AR will work with the cycling.
 
Have never experienced a 300 bo from 16 in barrel. However a suppressed full power 223 is likely quieter than an unsuppressed full power 300 bo. Am also guessing that a suppressed full power 223 is quieter than an unsuppressed sub sonic 300 bo.

The suppressed full power 223 will have more umph than a sub sonic 300 bo, and shoot flatter.
 
I can only tell you that a supressed 223 sub sonic the only thing you hear is it heading the plywood on my backstop like a bing, and that is what I'm looking for in the 300. Question: After you put 300 you put bo, what does the bo stand for?
 
zeke; you have been around suppressed full power 5.56 ? or have you ?

they are not quiet. the supersonic crack of the projectile is about 80% of the sound. the unsuppressed exhaust gas is maybe 18~19% and the mechanical noise is the remainder.

just saying.
 
BO is short for “Black Out” also known as 300AAC.
In a 16” barrel with no suppressor, 300bo is noticeably more quiet than .223 and subsonic 300bo is even more quiet than .223.
All of the magazines that I use for 300bo has stickers and duct tape to identify them. I still look at bullets before using any of my ARs.

I would also choose the first upper on the link, as others have mentioned.

If you are only shooting targets, then FMJ (full metal jacket), OTM (open tip match) will work for you. If you intend to use the firearm on meat-based life forms, you’re going to want something designed for hunting that intentionally expands on impact.
 
georgehwbush said:
zeke; you have been around suppressed full power 5.56 ? or have you ?

they are not quiet. the supersonic crack of the projectile is about 80% of the sound. the unsuppressed exhaust gas is maybe 18~19% and the mechanical noise is the remainder.

just saying.
Click to expand...
Yes i have been around suppressed 223 in 16 in, 10 in and 11.5 in. And never said they were quiet.

What i did say was "However a suppressed full power 223 is likely quieter than an unsuppressed full power 300 bo"

just saying
 
Zeke - In your last post to me, you put 300 BO. I had asked, but I guess you didn't see it, what does the BO stand for?
 
BO=Blackout = 300 aac = 300 ac blackout = 300 whisper (mostly)

rickyrick stepped in answered above. And he's got a lot more experience in it than i.
 
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To RickyRick - From your post "BO is short for “Black Out” also known as 300AAC.
In a 16” barrel with no suppressor, 300bo is noticeably more quiet than .223 and subsonic 300bo is even more quiet than .223.
All of the magazines that I use for 300bo has stickers and duct tape to identify them. I still look at bullets before using any of my ARs.

I would also choose the first upper on the link, as others have mentioned.

If you are only shooting targets, then FMJ (full metal jacket), OTM (open tip match) will work for you. If you intend to use the firearm on meat-based life forms, you’re going to want something designed for hunting that intentionally expands on impact."
I thank you for what BO means and etc. If I go this route, trust me when I tell you that EVERYTHING will be mark with the appropriate type. The most I will be using the BO for is target practice hitting plywoodl, but alot of it. My mag will be loaded with something for the 300 to take down a coyote if one comes around my place, but I would like a silent kill, not a noise to wake up the dead. Then if I get a chance to go out one night and shot coyote, then "YES" FMJ. Got any ammo in mind being quite without a suppressor?
Thanks
 
@RickyRick - Need a suggestion about the ammo for the 300 BO as far as it being quite without a suppressor. Got any in mind?
Thanks
 
What, specifically, are you using the rifle for? Is this just something that you target shoot with or are you using it for more "serious" purposes where a low sound signature is required/desirable? The point, as I understand it, of .300 Blackout is to have a subsonic, and thus easily and effectively suppressed, cartridge that gives up as little ballistically to supersonic cartridges like .223/5.56. There are really only two ways to make a bullet more powerful: you can increase the velocity or you can increase the mass of the bullet. Because the speed of sound is approximately 1100 fps, the only way to make a more powerful subsonic cartridge is to load it with a heavier bullet. As such, subsonic .300 BO ammunition is usually loaded with bullets of 200 gr or more at 1000-1100 fps as opposed to the much lighter 55-77 gr bullets at nearly triple that velocity typically loaded in .223/5.56.

If you're just target shooting and aren't really concerned with the terminal ballistics of the bullet because, after all, it doesn't really matter if you're just punching holes in paper, an easier and more cost-effective option might be a .22 LR conversion kit for your AR-15 such as this one from CMMG:

https://cmmg.com/22lr-ar-conversion-kit-bravo-w-3-magazines-blk

A .22 LR is commonly available in subsonic loadings which, even unsuppressed aren't very loud (many people shoot unsupressed .22 LR without even bothering with hearing protection though I don't necessarily recommend this). Also, because .22LR uses nearly the same diameter bullet as .223/5.56, you would likely be able to use the suppressor you already have which should be at least as quiet as the subsonic .223 ammunition but wouldn't require you to manually cycle the action for every shot.
 
@Webleymkv Your suggestion/recommendations are for good. What am I using the rifle (AR15) for. Okay, in the end after the sights are zero, there are two things I'm going to do with it. The first thing is to payback 7 coyote's for taking my cats away from us that we dearly loved. The second thing is to protected this property from anything that might come up the driveway. Being ex-Army I'm use to the M16. I can clean, clear the M16 in anyway shape or form. So it's natural to get an AR15. When the second comes, I'm taking off the silencer and shooting it as I don't care who hears the rounds. But between that time and now, I would like all rounds that I shot quite. Because the AR15 doesn't re support subsonic, I would like to get he 300BO.
As for the .22LR, got one, but honestly, I hate cleaning that darn thing.

I hope this answer your questions
 
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