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300 Blackout Question

For what? Accuracy? Hunting? Terminal ballistics? Fun?

Ton of fun and the most versatile AR-15 cartridge in my opinion if you reload and have a suppressor. With a quality barrel it’s easy to reload MOA or better. Good for hunting medium game in the shorter New England hunting distances, similar to 7.62x39 for home defense/zombi apocalypse.

Did I mention it’s my favorite caliber to reload lol? You can do something with just about any 30 caliber bullet. Which can make it very economical for plinking. But they also make some bullets that are very high performing for a relatively underpowered rifle cartridge, such as the 110 gr. Barnes tac tx and the Hornady 110 gr vmax.

You also can have a lot of fun with it without a suppressor. The supersonic loads generally are easier on the ears and have less muzzle blast than the 5.56 I’m my experience. And if you load subsonic they’re very pleasant to shoot even without a suppressor.

That said, for the non-handloaders I’d probably stick to 5.56. I don’t see any real advantage from what is commonly available off the shelf.
 
I have both a 10-1/2" (might be 10") barreled upper and a 16" upper in 300 Blackout. Both are solid shooters. It really comes down to WHAT you want to do with it, the bullet weights you want to use, and the twist rate of the barrel. Get a good twist rate and you can shoot pretty much all the ammo made (or you make).

I know another NES member with a shorter barrel for 300Blk (8.5" I believe). With 147-150gr projectiles loading above 50% of the recipe charge starts producing a nice fireball. Closer to the top and it's even 'better'. ;)

Personally, I've been using 147gr ammo in both. Just haven't gotten around to trying out any subsonics for it (or making any).

BTW, Barnes VorTex (110gr) are "DRT" rounds (dead right there). There's videos out there showing the impact the different ammo makes on things (like melons). The 110gr pretty much vaporize them. 200gr+ react more like a pistol round (9mm/45ACP) in that they don't destroy that much. I have a mag loaded with the 110gr for "home defense".
 
Fun and plinking to start off.

My son heard that it is optimized for shorter barrels and questions using it in a 16".
 
Fun and plinking to start off.

My son heard that it is optimized for shorter barrels and questions using it in a 16".

Generally, what people mean when they say this is that most of the powder burn occurs within the first 9" or so for most loads. That is true. However, Optimal means different things to different people. Is that the optimal length for a hunting set up? I would say no. You still gain, in my experience, at least 20 fps per inch thereafter. So a 16" barrel is likely to generate around 140 fps or more than its 9" counterpart. In a relatively low velocity cartridge like the 300 AAC Blackout, this makes a difference in hunting applications and for those who want to extend their maximum point blank range. I tend to believe that the term "optimal" in regard to a SBR in 300 became popular because the 300 loses less energy between 16" and 9" than its 5.56 counterpart, which does not have a full powder burn in SBR lengths. But that doesn't mean that the 300 in shorter lengths is optimal compared to the 300 in longer lengths. That depends on your application.

My next question would be will it be supressed? If not, then yes the 16" barrel is going to be far better on the ears, and far better to plink with all day long without feeling punch drunk. Even though the bulk of the powder burns within 9 inches or so, there is a signifficant reduction in recoil blast in a 16" vs. a 9" or shorter. Even supressed, if you are looking for as quiet as possible, the longer the barrel the better. And the 16" will be much quieter than the shorter barrels.

In my opinion, where the shorter barrels shine is when they are suppressed. And not because they are quieter or suppress better at all. They don't. Its just that a 9" barrel with a suppressor is going to handle a lot better than a 16" barrel with another 4-8" hanging off the end of it. When you shorten the barrel you are losing velocity, and gaining muzzle blast. Even with that suppressor on the end of it. But you are gaining is that it is much more handy at shorter lengths with a suppressor than the longer 16" barrel.

For me, Optimal hunting length would be 16-18. Optimal for quiet and least amount of muzzle blast would be 16-18 suppressed. Optimal for home defense would be 16" with supers unsuppressed. Optimal for tacticool fun plinking would be somewhere around 10.5 suppressed with subs.

The best part is, in an AR15 platform you can have all of those with the change of an upper.
 
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A 16” 300 BLK with supers is fine. You’ll get a bit of velocity bump from the SBRs and have slightly flatter trajectory and range. It would make a fine non-NFA deer/hog/home defense rifle when loaded with 110gr tipped expanding solids like Barnes TTSX.

What you need to remember, though, is that it uses pistol powder or very fast burning rifle powder. It performs well in short barrels due to the faster burning powder. So you get diminishing velocity returns on barrel length with supers and a longer barrel isn’t getting you any benefit with subs. This is dependent on powder used, of course.

If the NFA weren’t a thing, almost all 300blk barrels would probably be 12” or less.
 
Since they tend to use a pistol length gas system regardless of barrel length, you can cut it down to whatever you want later on.
 
Boring nothing-burger shooting supersonic 300BO. Its a fat and slow . 223/556 plain and simple. Now if you handload subsonic and have a supressor, now you opened up a whole new steel gong smacking niche shooting enjoyment with 300BO.
 
I know everyone on the internet says there is no use for a 16" 300blk because they read on the internet that it is designed to work out of short barrels, but I pretend to hunt deer with one every fall. I have chrono'd 110grn Barns black tips at ~2350fps and it shoots that ammo .75-1 moa with ease while being one of my lightest rifle setups even with the can. My long shot around here is 100-150 yards because of the thick woods, it is more then capable in my area. I like it so much, I stopped by Green Mountain Rifle Co and bought their 9" version of the same barrel for my daughter to build a hunting upper of her own.

IMG_20191126_170913723~2.jpg

I don't shoot it for fun because 300blk ammo is retarded these days, but I would if I were rich.
 
Since they tend to use a pistol length gas system regardless of barrel length, you can cut it down to whatever you want later on.
May need to open up the gas port when doing so, but yeah.

Boring nothing-burger shooting supersonic 300BO. Its a fat and slow . 223/556 plain and simple. Now if you handload subsonic and have a supressor, now you opened up a whole new steel gong smacking niche shooting enjoyment with 300BO.

Supersonic 300blk has its advantages. It is better at immobilizing hogs with more effective hits on their tough shoulders. It is also much better at barrier penetration than 5.56 against things like auto glass or doors. And I say this as a 5.56 fanboy.


I know everyone on the internet says there is no use for a 16" 300blk because they read on the internet that it is designed to work out of short barrels, but I pretend to hunt deer with one every fall. I have chrono'd 110grn Barns black tips at ~2350fps and it shoots that ammo .75-1 moa with ease while being one of my lightest rifle setups even with the can. My long shot around here is 100-150 yards because of the thick woods, it is more then capable in my area. I like it so much, I stopped by Green Mountain Rifle Co and bought their 9" version of the same barrel for my daughter to build a hunting upper of her own.

View attachment 648626

I don't shoot it for fun because 300blk ammo is retarded these days, but I would if I were rich.
Very nice.

A 9” will easily get you effective terminal performance from a 110 TTSX in east coast hunting distances.

That said, my 9” chronos Barnes Tac-Tx at 2142. Barnes loads are a little soft, but still your 16” gets an extra 100 yards of effective terminal performance from that bullet. Nothing to sneeze at, doubling the (admittedly short) effective range. Great option for hunting medium game.
 
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