Blah blah blah... 300 AAC. Blah blah blah 300 Blackout. Blah blah blah 300 Whisper. What is all this talk about this cartridge??? Well, I started to investigate this further and I like what I see.

History
The 300 Blackout (also known as the 300 AAC Blackout) was "redefined" by a silencer company called Advanced Armament Corp. The goal was to produce a larger caliber bullet that can be fired from a 5.56x45 AR15 platform. This is not new. Many have tried before. Some have just used the AK round (7.62x39) but failed because the ammo is so tapered that it required special magazines or a modified lower receiver to accept AK mags. Also, the bolt carrier needs to be replaced, as well as the buffer and buffer spring. Then there is the 6.8SPC. Same 5.56 magazine but still needed a heavier buffer and spring, new bolt, AND the recoil was MUCH more than the 5.56. In all three system (5.56, 7.62x39, and 6.8SPC) systems, if you choose to shoot subsonic and/or run a suppressor, you will need to change the gas system to be adjustable (or risk failures).

Advanced Armament took the standard 5.56 cartridge, cut it down, and renecked it to accept a 30cal bullet. The dimensions are 7.62x35. This way it uses the same magazine, same bolt, same buffer, and same spring. Basically, the only thing you need to change was the barrel. Great! This caliber also allows you to run subsonic ammo without changing anything!


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Since you are running a heavier bullet (110gr -> 220gr) the bullet drop is more, but the trade off is the amount of energy that is retained by the bullet. A better overview can be seen by watching this video


http://youtu.be/tgKjbySsAik

Ironically, this caliber "isn't" new. Advanced Armament really didn't invent something new. What they really did was convince a lot of people (and the military) to seriously look at this for combat effectiveness. Once proven, they spun a very well directed marketing campaign to make this bullet more visible to the world... They marketed it to tactical nuts like me.

The 300 AAC Blackout is pretty much the same as the 300 Whisper. It's wildcat cartridge that was not so popular because due to it's trademark issue. Since Advanced Armament isn't shy about the trademark of this caliber, they pretty much let any manufacturer use it. Because of this, several hundred manufactures have jumped on this bandwagon. From barrel MFGs, scope MFGs, to ammo MFGs, they have lined up to make "something" for this cartridge.

But why? Is it that much better? I'm starting to think so. It's not a long range gun. For the regular folks, it's a 300 yard gun. It can reach out 500+ yards, but its not practical after 500. Either way, it's a gun that packs a LOT more energy than a .223/5.56. When using a 110-125gr bullet, it can take out a deer. It's not intended for big game like elk. It's not really a hunting caliber... unless you are hunting bad guys. When running subsonic with a 220gr bullet it's energy is outstanding for under 100yd and is quieter than a 9mm (suppressed or not). When suppressed, its decibel rating is more like a exaggerated fart.

Cost for ammo is more (when you can find it). $13.00/20rnd of 115gr plinking stuff. $20.00/20rnd for 220gr subsonic. $29.00/20rnd for 110-125gr ballistic tip for hunting. That's pricy compared to $8.00 for 55gr FMJ in .223/5.56.

Finally I had a chance to shoot some 220gr Remington UMC subsonics from a 16" barrel AR. Oh my. The recoil was much less than a .223/5.56 and it knocked the heck out of my steel plate. I was sold. I spent months trying to find ammo. Besides the current ammo shortage, the demand for 300 Blackout ammo has been nuts. Remember the cost? Well, reloading will bring my cost of the 220gr subsonics to under $10.00. Ballistic tips to around $12.00. Now we're cooking with fire! Last month I invested $700 on reloading equipment. This week I built 10.5" 300 Blackout upper for under $400. Yesterday I spent $500 on reloading components.









I'm well vested in this project. Soon, this may be replacing my dedicated 5.56. Next year (when I replenish my toy fund) I'm definitely going to put a suppressor this one and probably use it as a home defense rifle and pig gun. I will also be filing my Form1 with ATF and registering two more AR lowers to be SBR (short barrel rifle) receivers. This way I can have a shorty 300 Blackout, 9mm, and my original 5.56.

For those of you that are still on the fence with your AR build. You can buy a 5.56 upper for $270 from DS Arms. This is NOT a bad choice. It's a proven choice for many years. If you are considering the 300 blackout, check out Model 1 Sales. They offer a 300 Blackout upper for $385, minus the bolt carrier and charging handle. If all you have is a stripped lower, you can buy a kit for $550.

One of the guys from my gym built one and let me shoot it. After I shot it I wasnt sure I liked it. Like you said it wasnt loud and it didnt kick. I didnt know that going into it so I felt like I was shooting a .22 and I was thinking it was going to be more like an reg AR. After I got over that and was able to hit the steel with no problems, I was sold.
That should make a great pig gun.

why the IMR 4227? most people use H110, A1650 or Lil Gun for 300blk. I also reload for 300blk and am saving my pennies for a can because shooting subsonic without one is just silly. Im working up a hunting round now with 125gr ballistic tips.

one thing to look into is the COL of your rounds. There is a rib inside of the AR mags that wants to press on the bigger bullet and can knock it off center. I reload shorter then mag length to avoid that rib. Some people file it down so its a non issue but i'd rather leave everything stock so i can use any mag i pick up and not a 300blk specific one.

ShmUDE wrote:why the IMR 4227? most people use H110, A1650 or Lil Gun for 300blk. I also reload for 300blk and am saving my pennies for a can because shooting subsonic without one is just silly. Im working up a hunting round now with 125gr ballistic tips.

As much as I like H110 or Win 296, and Lil' Gun, they are hard to find. Ibwas lucky to find tjis IMR 4227. It works for both super and subsonic.

The YHM suppressor is the best value I can find. I will use it on both the 300 blackout and my .308 win Armalite AR10 SuperSASS.

ShmUDE wrote:one thing to look into is the COL of your rounds. There is a rib inside of the AR mags that wants to press on the bigger bullet and can knock it off center. I reload shorter then mag length to avoid that rib. Some people file it down so its a non issue but i'd rather leave everything stock so i can use any mag i pick up and not a 300blk specific one.

What is your COL? I did read anout this, too. Are you in AZ? I would love to see your load process and setup.

fatbob309 wrote:One of the guys from my gym built one and let me shoot it. After I shot it I wasnt sure I liked it. Like you said it wasnt loud and it didnt kick. I didnt know that going into it so I felt like I was shooting a .22 and I was thinking it was going to be more like an reg AR. After I got over that and was able to hit the steel with no problems, I was sold.
That should make a great pig gun.

Build it, Bob. Build it!

2ndchance wrote:What is your COL? I did read anout this, too. Are you in AZ? I would love to see your load process and setup.

yeah, im local. North Mesa area. My reloading setup is pretty miniscule compared to some. Im using a Lee turret press, lee 300blk dies with crip, Digital scale from cabela's, lyman tumbler, home made case lube, CCI primers, 208gr hornady match bullets and 125gr ballistic tip for a hunting round.

My COL is 2.060 if i remember right off the top of my head with the 125gr supersonic. I went mag length on the subs i was shooting with a buddies can 2.260 i think.

Nice and simple! I've been loading straight wall stuff since 1994. Bottlebeck stuff is new to me.

I'm running a Dillon RL550 with 5 quick change heads. Reciently I bought a RCBS single stage.

Are you using the lanolin/alcohol mix for your lube? That's my next thing. I have to find a source for pure lanolin. Safeway has the alcohol.

2ndchance wrote:Nice and simple! I've been loading straight wall stuff since 1994. Bottlebeck stuff is new to me.

I'm running a Dillon RL550 with 5 quick change heads. Reciently I bought a RCBS single stage.

Are you using the lanolin/alcohol mix for your lube? That's my next thing. I have to find a source for pure lanolin. Safeway has the alcohol.

yep, i called around and found the lanolin at health food stores. I have a sprouts right down the road from me and they had it. It separates pretty bad when it sits so you just have to remember to shake it up before you spray your brass. I sized 50rds just to see how it worked and it was perfect. Tumbled after to clean them and they were nice and shiny.

After some disappointing attempts to load this round, I think I finally cooked up the correct subsonic load for my barrel lengths.

Sierra SMK HPBT 220 grain
IMR 4227 powder; 10.5 grain
.223rem brass cut and formed, sized and trimmed to 1.358"
Overall length seated to 2.190", with a light taper crimp.

I'm pulling an average velocity of 1007-FPS with a 16" barrel. 887-FPS with a 10.5" barrel. Obviously, this is a Subsonic load. Not good for general hunting as the Sierra SMK bullet may not expand very well. Although it's a hollow point, it's really designed for target shooting.

I had some problems with failure to feed with some of my loads I did to test velocities. Turns out that I had some crappy PMP South African brass mixed in with my Federal, Remington, PMC, and Fioochi brass. It tooks some time to filter out those crappy PMP rounds, as I had prepped over 1,200 rounds of brass.

Although the original load data had the overall length at 2.600", it had issues feeding from my Magpul Pmags. I think this length was originally set for Thompson Contender barrels and the lengths were originally for the 300 Whisper. The recent data I found has the case length at 2.190" so it does feed better.

Now that my subsonic load is finished, I need to work a load for hunting. I am considering the Hornady A-Max 110 grain and Speer TNT JHP 125 grain. Both are the most price conscience (under .25cent per projectile), and readily available in most stores. Any thoughts on this?

i haven't been able to find the 110 Amax so i went with the 125gr ballistic tip. It is what PNW arms uses in their 300blk hunting round so i figured i would copy that. http://store.pnwarms.com/rifle-ammo/300-aac-blackout/300-blk-hunting-125gr-ballistic-tip-box-of-20.html

where were you seeing the 110gr amax? im using 125 ballistic tips because thats what PNW arms uses for their hunting rounds and its reasonably priced at 17 bucks per 50 rounds.

I have not found any 110gr Vmax. I just saw the load data so I thought I would try to find them. No luck. I did buy 200rnds of 125 ballistic tip and will work with that. My Hornady case prep center took a dump on me. It's going to get shipped back tomorrow for some new gears. In 2 weeks I will start up again.

does your subsonic load lock back the bolt after the last round?

It does lock back. However I am finding that I'm getting a lot of blowback. I'm getting sandblasted by debris coming out of the ejection port. It may be unburned powder. I'm debating if I want to risk dropping the powder charge from the min of 10.5 to maybe 9.5.

i'd try it. Worst case you have to pound out a squib stuck in the barrel. Not THAT big of a deal.

shot my supersonic (hunting) load yesterday. At 50yds my best group was probably 3 inches so it definitely needs some tweaking. I might make the OAL longer and add a crimp to it and see if that helps. Here are pictures of the target and a closeup of the best group.

I was flipping around www.300BlkTalk.com and found several postings of guys using their 9mm suppressor to run subsonic 300 blackout rounds. This was interesting to me as I was about to spend $600 for a 30cal suppressor and $200 for the federal tax stamp. Instead, I was able to order a thread adaptor to convert the 5/8-24 threads on my barrel, to 1/2-28 to match my AAC Evo9 suppressor. A steal of a deal at $40 for the adaptor, and I picked it up from DSK Armory. The one that have looks like this, but is matte black finish.

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I was still skeptical about this, so I called AAC (advanced armament) and they verified that I can shoot subsonic 300 Blackout rounds out of the 9mm suppressor, so long as it's not full auto or crazy pressures.

Good news!

Thats awesome! Do you need a stamp for each suppressor?