.300 Blackout

[Mecanik]

I'm wanting to put together an AR-15 in .300 Blackout. Has anyone got information on the do's and don't of that caliber. Has anyone actually done it here. I've done some reading and it seems like the caliber I've been looking for.
1. Deer capable
2. Medium size case that will feed from a standard AR magazine.
3. Easily obtainable brass that can be made from .223 brass.
4. Standard .30 cal bullets. Seems like the perfect caliber to me.

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[Will_Power]

I bet Googling through ar15.com for info on it and the .300 Whisper would give you a ton of info.

 

[zerooption]

I bet Googling through ar15.com for info on it and the .300 Whisper would give you a ton of info.

AR15.com and M4 Carbine has a lot of information. Google will also provide a lot. Yep you are correct in points 1 to 4, I got the dies, the shells, and everything to start my build just need to get the barrel

 

[nubus]

I hope to have more barrels next week.
I have opted for the Olympic Arms barrels because they are stainless and use a pistol length gas system.
This cartridge has similar pressure and case volume as a 7.62x39, it may not function reliably with a carbine gas system on a 16" bbl.
If used with a suppressor it will cycle just fine, but of course that depends on your load and your wallet!
Most people pursuing this load are doing it for it's awesome suppressed abilities.
The full power 123gr loads are quite impressive though, no 6.8 for me!
And yes, I have built several in Whisper and Blackout.

 

[civilian75]

I hope to have more barrels next week. I have opted for the Olympic Arms barrels because they are stainless and use a pistol length gas system.

What's the twist rate on those AO barrels?

 

[nubus]

The Olympic 300BLK barrels are a 1 in 10 twist.
My hand loaded 240gr SMKs stabilize just fine.
They sound amazing through an AAC 7.62SD.
The Remington 220gr stabilized fine as well.

 

[civilian75]

What is the best known 300 BKO hot load emulating 7.62x39 ballistics? I ran up some numbers and it appears 21.0gr of IMR 4227 or AA5744 under a 123gr FMJ are good candidates.

 

[nubus]

Sierra has published Whisper data.
I like using AA1680.

 

[Mecanik]

I have no interest in suppression loads. My intention is to make an actual deer capable rifle that is equivalent to the 30-30 but with much better accuracy. I handload everything I shoot and .223 brass is as common as dirt so it seems natural to me. I got lots of powder and bullets too so all I need is the barrel and lower receiver parts.

 

[Dan-Dee Sales Inc]

This is from the Noveske's website.
The Noveske 300 AAC BLACKOUT is designed to run optimally firing both subsonic suppressed and supersonic unsuppressed, while keeping supersonic suppressed reliable. It may not reliably cycle the action under adverse conditions with subsonic ammunition unless a silencer is attached. We recommend supersonic ammunition for Military, Law Enforcement, and Self Defense use without a silencer.

Website on that caliber. <broken link removed>

 

[rsilvers]

There are gel tests on that site and Remington AccuTip is coming out this year.

300 AAC BLACKOUT High Speed Video 20% gel - YouTube

Also there is info at 300BlkTalk

You can do a 130 T-TSX load, as Bill Wilson used to hunt with.

 

[rsilvers]

I hope to have more barrels next week.
I have opted for the Olympic Arms barrels because they are stainless and use a pistol length gas system.

16 inch with carbine gas is perfectly able to cycle within M4 specs (more than 700 rpm) with subsonic ammo and no can - even with an H2 buffer.

While there is nothing wrong with a 16 inch barrel with a pistol-length gas system, it would not be my first choice for the same reason why I prefer mid-length 5.56mm over carbine length.... Less gas port erosion, and bolt unlocking when the pressure is lower in the chamber. When Blackout came out, Noveske changed from a pistol to a carbine gas for the 16 inch barrel, and AAC's - who has the most development time, have always been carbine length.

But again - pistol is fine also, as long as the gas port is the right size.

There are no 123 grain loads anymore. It is 125 for the Match and AccuTip ammo, and 115 for the UMC. The website will be updated pretty soon.

 

[PinkhamR]

Both my .300 AAC Carbine (16") and Pistol (10") seem to cycle fine with the carbine gas system. Did have to relieve the gas port on the pistol just a tad. Just waiting on the 'CAN' paperwork to be processed ....

 

[G1GRANDEUR]

I believe it's illegal to put AFG / any kind of fore grips on AR pistol?

 

[PinkhamR]

I believe it's illegal to put AFG / any kind of fore grips on AR pistol?

ATF has published an updated decision. While a VFG is not allowed the AFG is now legal.

Thanx ........ Randy

 

[MilesTeg]

The only thing I disagree about with your statements is the conversion of .223 brass. From what I have been researching it seems a lot of labor would be involved in the sizing and trimming. The 300 shoulder starts below the current 223 shoulder etc. Not as easy to convert as say if you were doing 7mm TCU. However, new 300 brass is fairly inexpensive and that is what I will be doing myself. Unless you have a power trimmer and a lot of time - I would skip the .223 route.

 

[mjbskwim]

I just found a guy who does brass.Gets it ready for priming and loading.
And he does 300blackout
$100 per 1000
So $200 would get you a few years of brass,if you didn't compete with the blackout.

 

[MilesTeg]

Robert,

Welcome to NWFA! Like the idea of the TSX loads in the 300Blk. Will you be publishing loads on the AAC site for reloaders?

There are gel tests on that site and Remington AccuTip is coming out this year.

300 AAC BLACKOUT High Speed Video 20% gel - YouTube

Also there is info at 300BlkTalk

You can do a 130 T-TSX load, as Bill Wilson used to hunt with.

 

[Onajoyride]

I built a 300 blk it's the most fun gun to shoot and take out blasting. I would do a 1:8 twist barrel so you have the stability on the larger projectiles. If you have a dillon you can process brass all day long faster than anything. I would avoid AR15 there is a LOT of misinformation on that site mostly from people pushing the 6.8 go to 300blktalk.com for accurate info. I also use the 130 ttsx it's a nice projectile very accurate. If your looking for a great company to buy an upper, whole gun, or just a barrel google Delta Company Arms. They have amazing customer service and very competitive prices. Rsilvers that posted above is the guru that works for Remington that is heading up the development of the round he knows his stuff. Here is the gun I put together. I went with the Lar Grizzly OPS-4 side charger to eliminate the gas in my face. If you have ever shot a 223 suppressed then you know how much fun it is to get blasted in the face by hot oil and cordite.

 

[Page.k]

I hope to have more barrels next week.
I have opted for the Olympic Arms barrels because they are stainless and use a pistol length gas system.
This cartridge has similar pressure and case volume as a 7.62x39, it may not function reliably with a carbine gas system on a 16" bbl.

So have you tried this setup with a "CAN" on it? And if so did it over drive the bolt or made the bolt to bounce? What condition are the bolt locking lugs in now?
I can say that the 7.62x39 case taper makes it so it can be ejected from the barrel easy while still under pressure. Second that round in an AR is a pain to find good mags for over 10 rounds that will work with your gun.