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Any reason for 300BLK if I can't SBR or suppress it?

dang472

dang472

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    • Feb 3, 2012
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    Kingston, IL
    I've got a bunch of uppers and lowers to build some ARs and I hear everyone talking about the 300BLK. I plan on a 6.8 SPC II build, I already have a 458 Socom close to medium range carbine, and I can't suppress anything in Illinois. Is there anyone that can provide compelling reasons to build a 300BLK when I have everything else seemingly covered? I have plans for a long barrel 6.5 Grendel, an 18in SPR, and a 204 Ruger so I think I'll have more than I know what to do with.
     
    Far as I can see .300 Blackout is designed to be used as a Suppressed SBR. keeping overall length down while still maintaining terminal effectiveness at short to medium distances. If you cannot suppress it, I see no reason for you to get .300blk over 6.8 spc, which is a much better performer for a longer distance.
     
    That's pretty much my thinking as well. It is cheaper to make 300BLK brass from my piles of 223 brass though.
     
    Every time I come close to buying a 300BLK I just end up going, why? I don't SBR, I don't have any suppressors, and if the wait wasn't so long I'd get a few. So I just go, well my AR's are really good, my AK's are really good and why do I need yet another caliber?

    I think you have your bases covered really well with the 6.8spcII, that is a rifle I would be way more tempted to own than the 300BLK, but that is me.
     
    I shoot my 300blkout 16 inch barrel Ar unsuppressed and un SBR all the the way to 600yds very easily, the beauty of the blackout is that you can run subsonic and supersonic in it. I have a friend with a can and we put it on my BLKout and played with both super and subsonic ammo, he now has his own to play with.
    brass is super cheap to make and bullets for it are everywhere.
     
    Here is one. If you were to build a pistol the muzzle blast is one reason, 5.56 pistols are LOUD. The heavy 308 bullets don't slow down and also carry lot more energy to the target using using a subsonic load than you could ever get out of a 6.8 subsonic. I think of it as a pistol with 45 ACP muzzle energy at 300 yards and with today's optics bullet drop can be compensated for. You can form brass out of 223 cases and just about every .308 bullet imaginable can be chucked out of it. And lastly you likely have all the parts except the barrel. The chart below is figured at a Sierra 220g at below 1700 FPS BC of .609 and a 1040FPS muzzle velocity.

    RangeVelocityImpactDropToFEnergyDrift
    01040-0.5005280
    1001006017.090.34941.26
    200978-33.8668.530.64673.64
    300954-103.92156.180.914457.43

    <tbody>
    </tbody>

    <tbody>
    </tbody>
     
    What Oakland Tactical said. Fire milspec 5.56x45 in a confined space like a hallway then fire 220gr subs in the same space. The 5.56x45 will leave your ears ringing even with earplugs and the 220gr subs aren't bad at all. Hopefully you will never have to use a gun to defend your home, the 5.56 will do permanent hearing damage.
     
    Had a DPMS Sportical doing the safe queen thing for more than two years. Always shooting a couple other AR's.

    A simple barrel swap later I have what I consider just a light, modern 30-30 carbine. Not a thing wrong with that.
     
    g22rmr said:
    Far as I can see .300 Blackout is designed to be used as a Suppressed SBR. keeping overall length down while still maintaining terminal effectiveness at short to medium distances. If you cannot suppress it, I see no reason for you to get .300blk over 6.8 spc, which is a much better performer for a longer distance.
    Click to expand...

    Exactly, the 300 BLK was developed and pushed by AAC to sell a new line of suppressors for their kool aid drinkers, mainly for the guys that were tired of shooting 9mm and wanted something a bit more.

    If you do not reload that would be another reason to pass over on it as well, because ammo availability was bad enough before the rush, forget about it now.
     
    And yes while .300Blk is indeed very quiet suppressed indoors compared to an sbr 5.56. the time of flight on .300blk gets a tad on the stupid side. In a fast pace real world situation, leading targets past 200 yards accounting for wind and target speed vs bullet flight time is just another disadvantage one shouldn't have to concern themselves with.
     
    I have an 8" 300blk sbr with suppressor. If I couldn't suppress or sbr I would have no interest in the round I would have gone 6.8 spc. But since I can it was the obvious choice very versatile common components, full mag capacity and a blast to shoot. I have not had a chance to hunt with it yet but expect it to perform well.
     
    If a suppressor and SBR stamp wasn't in the cards the only reason I would look at a .300 blk is for hunting. If you're not hunting either then just go on shooting 5.56 or get a 5.45 upper and burn through somewhat still cheap surplus.
     
    I liked it. I jumped on the 300 blackout band wagon when the round came out because no one made a reliable 7.62x39 AR, or there was a million year wait to get one, so the easy alternative, and cheap since 90% of the gun is the same as a 223 gun and I just had to change the barrel. Like the guys said above, make the brass from 223 brass, and I bought H110 powder and military pulled 147 gr bullets to shoot. I never took it past 300 yards, but it was awesome to shoot at that distance, didnt have a ton of recoil, it was super accurate, and after getting your brass done it really isnt much more than 223 to reload.
    Best part is all your 223 mags work for it and if you ever decide you hate it, just toss a 223 barrel back on it and sell the .300 barrel.

    All that being said, when everything started to happen with shortages, I went back to just 223 and 308 for my rifle calibers since I really didnt need an intermediate round and reloading supplies became non existent. If you dont reload, this is a bad round to get into due to the cost of factory ammo and how hard it is to find it... but if you want something with greater effectiveness inside 200-300 yards than 223, its a neat round that can be reloaded cheap.
     
    Last edited:
    I'm planning a 300 blk build once everything calms down. If I wasn't going to SBR and suppress it I would go with another caliber in the 15 platform.
     
    I'm a whole hearted blackout fan so this is biased that way. I I have a suppressor but no SBR. Even without the can I still would have ride it out. The best things about it are the ease of changing over, getting to use regular bolts and magazines (has to be a pita with the 6.8), and the "mild/moderate" nature of the round. It really is like a reliable 7.62x39 AR15, no superstar performance but sometimes that's okay (damn I must be getting old too)
     
    With the big bullets (180+), I believe it's the only sub sonic round that CYCLES THE BOLT on an AR platform. Yes, that makes it even better with a can, but it's a really low recoil sweet shooter in either super or sub sonic version. With subsonic ammo and no can, it can be shot outdoors with no ear protection (like a .22 short, with WAY more knockdown).
     
    If you were a handgun hunter and already set up to reload Whisper then it would be a short and easy step to a Blackout upper for your AR.
     
    I shot a hog at 200 yards with my 300 blk supersonic 110 vmax load and if you saw what it did you would realize that you do not have to have it sbr or supressed
     
    I love shooting my 300 blackout over my 5.56 on my SBR. Even without the can it is significantly quieter and more comfortable. Now with the suppressor and sub sonics, it's sooooo much fun! I honestly almost never use my 7.5 inch upper in 5.56 any more.
    Now, if I were not using it in an SBR with a suppressor, I would use 6.8 for game up to whitetail size out to 150 yards. Past that my AR10 comes out :)
    I also enjoy making my ammo from 5.56 casings....kind of therapeutic.
     
    g22rmr said:
    the time of flight on .300blk gets a tad on the stupid side. In a fast pace real world situation, leading targets past 200 yards accounting for wind and target speed vs bullet flight time is just another disadvantage one shouldn't have to concern themselves with.
    Click to expand...

    That is equivalent to criticizing the .338LM for its shortcomings as a CQB round, the BLK was not intended for long range work. Does your 3/4" socket suck because it wont turn a 7/16" nut? Right tool for the right job.
     
    One nice thing about the 300 BLK I didn't see here is the low cost of entry into the caliber:

    The only component of the rifle that is not a standard 5.56 component is the barrel. All other variants that run different calibers on the AR platform require different hardware of some sort (bolt, mags, etc) and thus additional investment. So if you want to experiment and have a standard AR-15 it's an ideal option.

    Also the BLK offers almost as much versatility as the .308 if you want to try different load recipes and projectiles. You can run subsonic or supersonic without fooling with gas block adjustments - a mag change is all you have to do

    Last thing to consider: if you are interested in any sort of barrel shorter than 16" (pistol or SBR if you live in a Free state) for the AR platform the BLK is superior - DirtyD mentioned concussion and noise but there is also the stability problem of a 5.56 projectile from a shorter barrel- they are prone to tumbling very quickly whereas the BLK is extremely stable out of shorter barrels all the way down to 7-9" .

    Yep-- I'm a fan
     
    No SBR or no can? Go another route as you just gave up the two reasons the 300blk is good for.
     
    Ill never understand the argument for 300blk that its cheap to change to it. Nothing we do is cheap in the workd of modifying firearms. Hell a quality handguard, a chunk of sliced and diced aluminum is well over 200 bucks. Is the argument FOR 300blk really a basis around not having to spend the additional 150 for a bcg and 20 bucks a pop for mags? I dont see that as some huge benefit as some of the fans call it. I dont think theres any reason to go with a 300blk if you're not going to suppress it. 6.8 does everything better in the supersonic spectrum.

    With that said I own two 300blk rifles and 0 6.8s. Ive got a can and once I get off my ass and make another $200 donation to the guberment I'll install an 8" noveske barrel. I bought this cartridge because I want to shoot subs to kill hogs off my feeder and swap mags to some 110 blacktips or 125 noslers to shoot whitetail all within 200yds. 110 vmaxs are fun on varmints or for a spine shot on whitetail.

    Every cartridge has its place but if you're not atleast going to take advantage of subs with a can there better options. 300blk for subs, 6.8 for intermediate range, 6.5 if you want to stretch the ar platform. Of course there are a ton of wildcats that do the jobs better but theyre pretty much a full custom deal.
     
    IMO not really. They're fun and all, but other than having a more accurate 7.62x39/.30-30 for longer ranges with better bullet choices supersonic you'd be missing out on my primary reason for wanting one. I shoot both supersonic and subs, but always suppressed.

    Again just my opinion, your criteria for the rifle might be different than mine.
     
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