The 300 blackout sucks, or does it....

[in2anity]

Let's be honest, the 300aac/"blackout" is not really a sub-moa cartridge. You can scour the interwebs and find anectdotes about "my sub-moa 300blk group" but mostly people are squeezing out around 1.5 moa, at closeish distances. Really, they are designed for a heavy subsonic FMJ, out of an AR style platform. Not exactly the most valuable traits down-under...

Nevertheless, shooting only light supers, I like the blackout for two main reasons, 1] they are cheap to run (~18grs of slow pistol powder under any budget 125gr 308 pill) 2] I can reanimate my dead 223 comp brass to 300blk. There are other reasons also, but are moot points compared against other calibers.

I have a Ruger American Ranch rifle in 300blk which I've shot quite a bit. There are whole threads on here dedicated to that gun. Long and short of it; whilst it's great for what it is, I found that while it was almost sub-moa at 50m, it was not sub-moa at 100m and beyond. Furthermore it was not consistent under match-like conditions, and tended to drift when hot, which is becomes bleedingly obvious at moderate ranges. I had the hankering to get it to shoot better.

My theory of the shortcomings of the factory 300 blackout are as follows:

a) The tight 1:7" twist barrel was over-stabilising the light 125gr supersonics, meaning any "wobble" was exaggerated once the pill moved beyond 50m.
b) The long throat designed to handle up to a 220gr monster meant the 125gr pill was jumping well over 100thou to engage with the lands.
c) Tight neck tension seemed paramount in achieving consistency; an undersized collet-die mandrel and crimp was required for peak accuracy. Perhaps this is because of the long jump, i.e. point b).

Given those observations, I decided to reconfigure my blackout to suite specifically a 125gr supersonic load. Looking at the specs for the AK-47; it sports a 1:9.45" twist with 16" barrel shooting roughly a 122gr pill. I thought the Ruskies were probably on to something.

So I ordered a custom barrel from Lothar-Walther to match the existing contour, only with a slower 1:10" twist, and a custom short-throat reamer from Pacific Tool & Gauge to match the 125gr pill.

10 months later (thanks COVID), the project is now complete:

Retrofitted, 1:10" twist 30 cal barrel. Short throated for 2.1" COAL.

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I took it out on Saturday and I shot crimpless FLS handloads on the 100m mound, off the bags, with an INSANE 30-40km/h fishtailing tail-wind (the hardest kind of windage) and here's the result:

Typical 100m group, shot quickly to combat 30-40km/h fishtailing tail-wind

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Now that my friends, is a true sub-moa 300 blackout. This little girl will be accompanying me more often to the Telescopic matches, and is my go-to hunting rifle (at 3.7kg fully kitted including sling).

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[Blr243]

Initial test firing of my Remington 300 AAC sps tactical indicated the rifle was capable of very good accuracy ..so it should it cost me twice as much as the ruger ranch. .it has a short thick rigid barrell and prob a 1/7 twist...with very basic ammo and a s**ty rest in the bush I remember moa group s But sadly I misplaced the bolt Somehow on a hunting trip and now it has a very boring life in my safe

[in2anity]

Blr - expensive gun to lose the bolt! The Ranch with its factory barrel would sometimes 3-shot moa at 100m, but it was inconsistent. And it was quite inconsistent on the 200m+ mound, especially during a match. No doubt the Remi barrel would trump the Ruger, but you'd hope so, given the price.

[on_one_wheel]

I was really surprised when people started using 300 blackout in Australia.
I just couldn't understand why you would when it's so difficult to legally obtain a suppressor here.

Whenever I read about loading for subsonic I think hmmmm

All that said, congratulations on getting yours dialled in

[bladeracer]

I was really surprised when people started using 300 blackout in Australia.
I just couldn't understand why you would when it's so difficult to legally obtain a suppressor here.

Whenever I read about loading for subsonic I think hmmmm

All that said, congratulations on getting yours dialled in

If you're going to use a suppressor you don't need subsonic ammo, without a suppressor is where subsonic ammo really shines.

[duncan61]

Great work.It is good when a plan comes together.I am in a very happy quandry myself as I have the following problems to solve.
.I have started attending a club that shoots early Saturday mornings up in the hills from 100-600 yards
.I have tried using my HOWA .243 But it is a 22 inch steel barrel on a plastic stock and the ammo we made a while ago is just field grade and the scope is one of them light up bushnells and The cross hairs are very thick.It is not grouping well at all so I have made some good ammo with Nosler 80gn that I had in stock and will try it one more time at 200 yards and if It does not group I will retire it for walking and hunting
.I have a .222 RUGER that I have put over 5000 through in my pro days that I could get a target barrel fitted to in .223 and lob 80gn pills that should be good for the 100 yards to 600 yards that the club range is.
I have a 7mm Rem Mag Sendero that I purchased for range work that has a sweet leupold scope and I have used it to 900 yards before and it is very capable however I need 2213sc powder which we can not get at the moment to use the 162 and 168 target bullets that Grandadbushy sent me.I have plenty of 2208 and could develop a load up to 130gn but will have to purchase the projectiles.The good bit is at 60 I am becoming recoil sensitive and the lighter pills would probably be a good thing.Bottom line all my gear is a mess but how much fun will it be tuning it all up again

[JimTom]

I use a 300 AAC and although know it is designed primarily for the US market in maybe an AR platform for hogs I use it here for closer range pigs. In saying that I have taken them at further distances.
Attached is a 5 round group at 100m hand loaded with 125gn SST and AR2205. Rifle is a Ruger American shot off the bench with a bipod and a rear bag. Believe it not.

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[JimTom]

Of course I can’t do that every single time however that is what the rifle is capable of. Not bad for a sub $800 rifle that included a scope.

[in2anity]

Of course I can’t do that every single time however that is what the rifle is capable of. Not bad for a sub $800 rifle that included a scope.

Yeah JT I was getting similar result to that, sometimes. They are not a target rifle though (not what they were made for) - that's just what I've essentially turned mine into. Consistency is king.

[JimTom]

Indeed mate. You have done exceptionally well. Nice little project with great results. Well done mate.

[Blr243]

Very nice group JT. That’s a 200 metre fox gun for sure

[JimTom]

Very nice group JT. That’s a 200 metre fox gun for sure

Yeah it’s possible mate however I think I’ll bring out the .223 on that occasion.
I’ll keep the 300AAC for off the Ute and in the close country.

[wanneroo]

I found this to be a very informative video that shows some data on barrel lengths and bullet weights:

https://www.youtube.com/watch?v=4VNl7QXykUY

After this video I bought some 110g Nosler Varmageddon bullets. It looks like 110g bullets might be the way to go.

The other thing I learned on another forum from someone doing extensive testing is that using purpose made 300 Blackout brass, not cut down 223 brass can provide better accuracy and a velocity jump of up to 100 FPS. As I have found with cut down reformed brass there is often an issue with thin necks and shoulders, where Starline Brass for instance has slightly thicker necks and shoulders and are consistent in their measurement. So I have bought some Starline 300 Blackout brass. If Starline Brass works well I plan on using Starline for my serious loads and all of the cut down 223 brass for my plinkers with cheaper bullets.

300 Blackout is a pretty good cartridge and I find now compared to five years ago, much more is known about it, many more specific products are available for it and people are figuring out ways to get the most out of it.

I am looking at getting either a CVA single shot 300 Blackout rifle or a bolt gun at some point to compliment the AR-15s in 300 Blackout.

[in2anity]

Thanks for sharing wanneroo, you are lucky that you get to play with modern semis. When it comes to forming your own brass from 223, I've found you really have to take it on a per/brand basis. For example I've found quality 223 brass such as Lapua is thicker than purpose made 300blk, while 223 brass like cheap Federal is thinner. Indeed the differing wall thicknesses can be problematic when forming (other threads cover this).

Case life and stretch is excellent on the blackout, miles better than other cartridges. I'm still on my original batch of Jagemann brass and there is no sign of it dying. Like pistol calibers, turning blackout loads around is a cinch, another reason I like regularly using the blackout.

The https://bergerbullets.com/twist-rate-calculator/ is a good start. You will see for a 125gr supersonic load, a slower than 1:7" is better. Still works O-K, but you start to see problems with consistency at say 300m, over a large sample size of groups.

[JimTom]

I converted a lot of .222 brass for the 300AAC, I used old Winchester and PMC brass and it worked well. Available somewhere on the net is a list of 223 brass brands that converts easily to 300AAC, as some brands were to thick from memory and caused issues around the neck.
I didn’t find any noticeable difference in accuracy between the formed up cases from .222 brass compared to brand spanking ADI 300AAC brass.
This is the link to the thread talking about the brass conversion for those whom are interested.
viewtopic.php?f=3&t=12157

[in2anity]

Annealing, and annealing uniformly seems important. I'm using the Kaseannealr machine and it's doing a way better more consistent job than I used to do.

[JimTom]

Yes mate, my process of annealing involved using a gas torch which I guess can be a bit hit and miss, so far as uniformity goes. I might do a bit of research into this fangdangled machine you’re using if you reckon it works well.

[in2anity]

Different techniques will yield different results. I have no doubt some people can anneal well, manually. Lots of different techniques. It's just I was doing the whole "lazy-susan-shallow-water-bath" technique and I just wasn't that consistent, for me.

[Die Judicii]

Hey there in2anity,,

Please don't take this the wrong way,,,, I'm NOT having a shot at you,, but from what I ascertain;

To start with you've described it (300 Blackout) for what it is, what it was designed for, and what it does.
Then moved on to describe all the intricate work and mods you've done to it, to make it do/perform what it wasn't designed for.

I believe all of us have at some stage played around with and modified various things to make them do something different, but I can't get my
head around it.

Why not just buy a "rifle" that was designed to shoot the projectiles that you want to use, with the accuracy you want,, in the first place ?

Or is it just a "Challenge" type of thing ??

Cheers Mate,,

[in2anity]

Why not just buy a "rifle" that was designed to shoot the projectiles that you want to use, with the accuracy you want,, in the first place ?

Or is it just a "Challenge" type of thing ??

Cheers Mate,,

For me DJ, it's largely the journey more than the destination I have fancy comp guns that bughole already. That and I like match barrels for matches, because they hold a better group.

[wanneroo]

Thanks for sharing wanneroo, you are lucky that you get to play with modern semis. When it comes to forming your own brass from 223, I've found you really have to take it on a per/brand basis. For example I've found quality 223 brass such as Lapua is thicker than purpose made 300blk, while 223 brass like cheap Federal is thinner. Indeed the differing wall thicknesses can be problematic when forming (other threads cover this).

Case life and stretch is excellent on the blackout, miles better than other cartridges. I'm still on my original batch of Jagemann brass and there is no sign of it dying. Like pistol calibers, turning blackout loads around is a cinch, another reason I like regularly using the blackout.

The https://bergerbullets.com/twist-rate-calculator/ is a good start. You will see for a 125gr supersonic load, a slower than 1:7" is better. Still works O-K, but you start to see problems with consistency at say 300m, over a large sample size of groups.

Well in my case what happened was back around 2014, products for 300 Blackout were not as common or more pricey plus we had a year and a half of panic buying post Sandy Hook, so I got a good deal from a company that took 5.56 or 223 brass and cut it down and reformed it and managed to get a couple of thousand pieces at a pretty decent price. And mostly it has worked pretty well but it's all sorts of brands of brass and the consistency is clearly not there. I'll use it until it wears out and I think it will be fine for plinkers on the range. My favorite load for that is bulk bought 150g Hornady FMJ with just over 16 grains of Lil Gun and it will ping a steel gong at 100 dead center with a red dot.

I'm excited about using 110g bullets to see what I can get with that.

[in2anity]

I got a good deal from a company that took 5.56 or 223 brass and cut it down and reformed it and managed to get a couple of thousand pieces at a pretty decent price. And mostly it has worked pretty well but it's all sorts of brands of brass and the consistency is clearly not there.

I did that as well, picked up a bag of mixed hs 223 range brass, only I did the cutting and forming work myself. And I sorted it all by hs. That taught me about how brand matters (in this context). Maybe you could sort yours?

[JimTom]

I'm excited about using 110g bullets to see what I can get with that.

Interesting and informative vid mate. Thanks for posting.

Although I am already achieving great results with the 125gn SST I may also give the 110gn a go just for sh1ts and giggles. Be interesting to see if I can anywhere near the accuracy that I do out of the 125gn.

Be sure to let us know how you go. I really enjoy my 300AAC and its good to be able to have a yarn about it on here. It is normally just poo pooed by the haters.

[marksman]

this is one of the most interesting informative threads l have seen

thanks for posting

[wanneroo]

I got a good deal from a company that took 5.56 or 223 brass and cut it down and reformed it and managed to get a couple of thousand pieces at a pretty decent price. And mostly it has worked pretty well but it's all sorts of brands of brass and the consistency is clearly not there.

I did that as well, picked up a bag of mixed hs 223 range brass, only I did the cutting and forming work myself. And I sorted it all by hs. That taught me about how brand matters (in this context). Maybe you could sort yours?

I could potentially do that but I'll just use it up for plinkers in the AR 15s. But now that I have Starline Brass I'll do the more serious loads in that and eventually over time if I am happy with Starline, I'll buy 500 to 1000 piece lots of it and eventually replace all the odds and ends as it wears out.

I do have some ADI brass from ammo I shot and maybe I will separate that out of the pile and do something separate with that. They sold ADI 300 Blackout here at Cabelas for a while for a reasonable price, wish I had bought more, as they don't carry it anymore. That brass seems pretty good.

I might look at Nosler brass as well as sometimes that comes up for sale at a reasonable price.

Just got the new Lee APP press bolted to the bench, so once I do some 9mm I am going to set that up for 300 Blackout sizing. I have close to 2000 cases to size.

Bullets I'll be using this year, 110g Nosler, 125g Hornady SST, 125g Hornady FMJ(cheaper target bullet Hornady is making for 300 BO now), 150g Hornady FMJ.

[wanneroo]

Interesting and informative vid mate. Thanks for posting.

Although I am already achieving great results with the 125gn SST I may also give the 110gn a go just for sh1ts and giggles. Be interesting to see if I can anywhere near the accuracy that I do out of the 125gn.

Be sure to let us know how you go. I really enjoy my 300AAC and its good to be able to have a yarn about it on here. It is normally just poo pooed by the haters.

The 125g SST is a very good accurate bullet at a reasonable price. I think it's pretty good but after seeing the math in that video and that the 110g has more velocity and foot pounds of energy delivered on target, it's worth giving it a try.

[JimTom]

Yep I agree mate. Will give them a try. Let us know how you go.

[in2anity]

Unsure of the math behind it, but if you punch the 110gr into https://bergerbullets.com/twist-rate-calculator/ (for a factory 1:7" twist barrel) it yields a better number than the 125gr. You want to be close but not under 1.5

[duncan61]

I am loving all the wild cats coming out based on the AR platform.How full on is the Beowolf and 450 bushmaster.I feel the 308 case may be sorted with all the options now we have the .358 Winchester

[wanneroo]

I am loving all the wild cats coming out based on the AR platform.How full on is the Beowolf and 450 bushmaster.I feel the 308 case may be sorted with all the options now we have the .358 Winchester

I have a bunch of lower AR receivers on the shelf I can build on and have contemplated building a 50 Beowulf or 450 Bushmaster rifle. I've shot 50 Beowulf full auto and it is quite the experience. Here in the USA in most states, the AR lower receiver is the controlled part which can be purchased for anywhere from $40 to $120 at the gun store with a background check and then you can build it into a "pistol" or "rifle" or "short barreled rifle"(with a $200 tax stamp from the Feds). You can buy whatever parts you want online or in person and build what you want, so that probably accounts for all the wildcatting and development of new cartridges as the possibilities are extensive if you are willing to build your own rifles and AR-15s go together like Legos for the most part.

Even the 300 Blackout got itself wildcatted with the 300 HAM'R.

Problem is that with all of these cartridges that come to market is typically they are "hot" for one year before the next big thing comes along, so in the end some of these will not make it in the market. 6mm ARC is the new hot cartridge for 2020 as a US military unit adopted it.

300 Blackout is here to stay, here in the USA I'd say it's the 2nd or 3rd most popular AR chambering and a popular bolt gun loading as well so it is very well accepted.