Does it make sense for me to build a 300 blackout AR?

[Flymph]

DO NOT SHOOT 5.56 NATO IN A .223 CHAMBERED RIFLE.

You can shoot .223 in a 5.56 NATO chambered rifle, however. Generally they will shoot what they are designed to shoot better. You can load 38 special into a .357 magnum, but you definitely would not want to load a .357 into a 38 special handgun.

I think 5.56 has a little more powder and is designed slightly different. Hold the two next to eachother and if you have keen eye sight you'll see the minute difference.

 

[Boboclown]

On the AKs it looks like they went to "billet steel" and forged trunions, so it looks like they remedied that.

Just checked, they went back to billet steel for the front trunnion. Tbh, an import would still be better for the money.

Other then a PSA is there a general go to BCG that would be better for about the same price?

Not that I can think of, I'd spend extra $$ on the BCG as well.

I think 5.56 has a little more powder and is designed slightly different. Hold the two next to eachother and if you have keen eye sight you'll see the minute difference.

5.56 has thicker brass, so they use a faster burning powder to compensate.

 

[Pandaz3]

I have been collecting parts lately, but waiting to buy a lower receiver..... Hey I already have a lower receiver, LPK,, just need a buffer and stock. Now you got me scheming.

AR Pistol for a 300 BO?

 

[Will_White]

DO NOT SHOOT 5.56 NATO IN A .223 CHAMBERED RIFLE.

You can shoot .223 in a 5.56 NATO chambered rifle, however. Generally they will shoot what they are designed to shoot better. You can load 38 special into a .357 magnum, but you definitely would not want to load a .357 into a 38 special handgun.

I think 5.56 has a little more powder and is designed slightly different. Hold the two next to eachother and if you have keen eye sight you'll see the minute difference.

Not a standard .223 chamber a .223 wylde chamber, it was designed as a compromise between the 5.56 chamber and .223 chamber but I still see some people that say you not shoot 5.56 through it which seems like it defeats the purpose of the chamber? Just wanting to verify.

Not that I can think of, I'd spend extra $$ on the BCG as well.

Any one in particular that you'd recommend?

 

[Boboclown]

Any one in particular that you'd recommend?

I'd go for a BCM BCG if I get back into the AR game.

 

[Pandaz3]

Not a standard .223 chamber a .223 wylde chamber, it was designed as a compromise between the 5.56 chamber and .223 chamber but I still see some people that say you not shoot 5.56 through it which seems like it defeats the purpose of the chamber? Just wanting to verify.

Any one in particular that you'd recommend?

.223 Wylde will shoot both well, I have a couple Wyldes, and more in 5.56, just don't use 5.56 in a regular 223 chamber. What is marked on a receiver does not matter, what is marked on a barrel does. I have a commercial Colt that says on the receiver, .223 Remington, but the Colt barrel says 5.56. I can shoot it all.

 

[langsethnw]

I like my .300 AAC but I don't like to pay the high price for the ammo. 50 cents or more per round and up to $1 per round for sporting ammo. Stick with the 5.56 caliber.

 

[Pandaz3]

BCG's I have two spares right now a Aero Precision, Black Nitride that I got on sale last month, they usually sell a parkerized and Nib versions also (Nib are the shiny silver ones, black nitride are the shiny black ones, and parkerized has that matte rougher finish)
My other one is a LanTac (My third LanTac, a little glitzy, but I like them.) Aero Precision runs a sale on theirs frequently if you get on their mailing list

 

[Lazyfaire]

I like my .300 AAC but I don't like to pay the high price for the ammo. 50 cents or more per round and up to $1 per round for sporting ammo. Stick with the 5.56 caliber.

I have both a Barrett AR in 300BO and a Sig 400 in 556. The 556 is less expensive to shoot. I will tell you that I had an issue where a 300 shell ended up in my Sig 556 magazine. The bolt didn't close and the primer was struck exploding the powder. Lucky that it was minimal and black powder everywhere. The bullet did fly but the cartridge was all jammed up in the chamber.
I now mark my rifle, mags and storage boxes in a colored tape. the mag and rifle colors must match. Red for 300 and Yellow for 556. I now only take one rifle at a time to shoot. Could have been much worse. Not a scratch in the barrel, and it still shot true!
The bad things are supposed to happen at the other end of the barrel!

 

[Flopsweat]

I have both a Barrett AR in 300BO and a Sig 400 in 556. The 556 is less expensive to shoot. I will tell you that I had an issue where a 300 shell ended up in my Sig 556 magazine. The bolt didn't close and the primer was struck exploding the powder. Lucky that it was minimal and black powder everywhere. The bullet did fly but the cartridge was all jammed up in the chamber.
I now mark my rifle, mags and storage boxes in a colored tape. the mag and rifle colors must match. Red for 300 and Yellow for 556. I now only take one rifle at a time to shoot. Could have been much worse. Not a scratch in the barrel, and it still shot true!
The bad things are supposed to happen at the other end of the barrel!

Glad to hear you're OK. I saw one blow up and destroy the upper. The owner sustained minor injuries. I have one 300BLK that goes on its own bench when we shoot. If there will be more than two people shooting it or there aren't enough benches it gets a tag. But I like your idea. Maybe I'll deck out the 300BLK rifle and mags in FDE.

 

[EPS]

DO NOT SHOOT 5.56 NATO IN A .223 CHAMBERED RIFLE.

You can shoot .223 in a 5.56 NATO chambered rifle, however. Generally they will shoot what they are designed to shoot better. You can load 38 special into a .357 magnum, but you definitely would not want to load a .357 into a 38 special handgun.

I think 5.56 has a little more powder and is designed slightly different. Hold the two next to eachother and if you have keen eye sight you'll see the minute difference.

The 5.56 is actually longer than 223 if you put them on I table primer down another words standing next to each other you will see 5.56 is longer it taller

 

[Camelfilter]

I have both a Barrett AR in 300BO and a Sig 400 in 556. The 556 is less expensive to shoot. I will tell you that I had an issue where a 300 shell ended up in my Sig 556 magazine. The bolt didn't close and the primer was struck exploding the powder. Lucky that it was minimal and black powder everywhere. The bullet did fly but the cartridge was all jammed up in the chamber.
I now mark my rifle, mags and storage boxes in a colored tape. the mag and rifle colors must match. Red for 300 and Yellow for 556. I now only take one rifle at a time to shoot. Could have been much worse. Not a scratch in the barrel, and it still shot true!
The bad things are supposed to happen at the other end of the barrel!

Glad no damage, yer freakin' lucky!

On top of different magazines (labeled painters tape), we "flag" our .300AC weapons out as well. Put labeled fluorescent yard trimmer line thru the action in a big hoop/loop. They're the only ones we flag the actions with in this way.

Since I charge (& empty as need be) our magazines, I'm very particular about keeping .300 completely separated. Labeled ammo cans, on separate shelves from .223/5.56.

Same with any charged .300AAC magazines ahead of time-although I don't normally keep them at the ready, but on occasion have charged some up for future range use. Canned, labeled, separate shelf from .223/5.56, normally next to the .300 ammo storage noted above.

 

[kod38]

For me it was simple. 5.56 nato , cheap to shoot , then build an AR pistol in 300blk to take advantage of all the dinged up 5.56 brass laying around.
You can even just have one lower and both uppers built.
They use the same bcg, charging handle , and mags.
Saving for a can now

 

[Lazyfaire]

Glad no damage, yer freakin' lucky!

On top of different magazines (labeled painters tape), we "flag" our .300AC weapons out as well. Put labeled fluorescent yard trimmer line thru the action in a big hoop/loop. They're the only ones we flag the actions with in this way.

Since I charge (& empty as need be) our magazines, I'm very particular about keeping .300 completely separated. Labeled ammo cans, on separate shelves from .223/5.56.

Same with any charged .300AAC magazines ahead of time-although I don't normally keep them at the ready, but on occasion have charged some up for future range use. Canned, labeled, separate shelf from .223/5.56, normally next to the .300 ammo storage noted above.

 

[Lazyfaire]

Since the bolt did not move all of the way forward there was an opening that allowed the back end of the cartridge to expand and split. No sign of where the primer went. I stopped and called the RO (who was an LEO and their armorer too) who could not get the bolt back either. Got a good deal on the Sig and then had to spend $125 to get it cleared! S**t

I had had a Ruger ranch rifle in 223/5.56 but traded it up for the Sig 400 in 5.56. At least I already had the ammo!

 

[langsethnw]

I have both a Barrett AR in 300BO and a Sig 400 in 556. The 556 is less expensive to shoot. I will tell you that I had an issue where a 300 shell ended up in my Sig 556 magazine. The bolt didn't close and the primer was struck exploding the powder. Lucky that it was minimal and black powder everywhere. The bullet did fly but the cartridge was all jammed up in the chamber.
I now mark my rifle, mags and storage boxes in a colored tape. the mag and rifle colors must match. Red for 300 and Yellow for 556. I now only take one rifle at a time to shoot. Could have been much worse. Not a scratch in the barrel, and it still shot true!
The bad things are supposed to happen at the other end of the barrel!

Oh boy, I have heard stories like that and I to made the same mistake, but never fired the wrong cartridge. Put a magazine full of 5.56 ammo in my 300 AAC and just before I pulled the trigger, double checked and found my error. Then another time I put a mag full of 300 AAC ammo in my 5.56 AR and chambered a round, again double checking and found my error. Know I use different color magazines and label the .300 AAC magazines. I also have port dust cover plates engraved on the .300 AAC on both sides.

 

[Lazyfaire]

Oh boy, I have heard stories like that and I to made the same mistake, but never fired the wrong cartridge. Put a magazine full of 5.56 ammo in my 300 AAC and just before I pulled the trigger, double checked and found my error. Then another time I put a mag full of 300 AAC ammo in my 5.56 AR and chambered a round, again double checking and found my error. Know I use different color magazines and label the .300 AAC magazines. I also have port dust cover plates engraved on the .300 AAC on both sides.

I color coded everything in line (storage bins, mags and mag well (left side). I use electrical marking tape. They are in bright colors. They don't match, I stop. The cartridges look alike and my eyes are not always able to easily read the imprinted on the base of them. Too expensive and too dangerous to make an error. Hope my mistakes prevent someone else from a worse fate.

 

[Flopsweat]

The 5.56 is actually longer than 223 if you put them on I table primer down another words standing next to each other you will see 5.56 is longer it taller

A buddy of mine stuck a 5.56 boresight in a .223 rifle and we had a heck of a time getting it back out.

 

[CLT65]

Here's a really good article on the actual difference between .223 and 5.56: 5.56 vs .223 - What You Know May Be Wrong - LuckyGunner.com Labs

I thought it was pretty interesting, learned something new. The cartridge case dimensions between the two are essentially identical. Any difference in brass can be attributed to manufacturing tolerances. The real difference apparently is in the looser chamber and freebore of the 5.56, and ammo typically loaded a little hotter for that slightly larger chamber. The article confirmed what I'd heard long ago; that the real world differences between the two are not that big of a deal, and shooting a few rounds of 5.56 in a .223 is not really that big of a deal either.

That said, I sure wouldn't make a regular practice of it, myself. While it won't blow up your gun, it sure seems to me that a steady diet would accelerate wear.

Added: I hadn't given thought to the potential to mix up .300 Blackout and 5.56mm. I didn't realize that it could chamber and make a mess. I'll be sure to be real cautious about that, and not get them mixed up. Thanks for that heads-up guys.

 

[langsethnw]

A buddy of mine stuck a 5.56 boresight in a .223 rifle and we had a heck of a time getting it back out.

Maybe someone has already pointed it out but the external dimensions of the 5.56mm and the .223 Rem are exactly the same. The 5.56 has higher pressure then the .223 from larger powder charge and 5.56 military brass is thicker. The reason your friends 5.56 bore sight got stuck in the .223 chamber is the throat (leade) is shorter in a .223 chamber then the 5.56. That's one of the reasons for advising not to shoot 5.56 ammo in .223 rifles because of dangerous chamber pressures because of the necks being slightly longer and more power charge. Shooting .223 ammo in 5.56 rifle is OK. I have a .223 Wilde chambered AR 15 Match rifle from White Oak Armament that you can cover 5 rounds with a dime at 100 yards.