Talk me out of a .300 BLK

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Gaerek

New member
So, I'm mostly a pistol guy. I only have one rifle, and it's a .22LR. Though recently my father-in-law and I have been talking about doing AR builds. It looks like it's something we're both going to do together. I have yet to purchase anything for it, but I do have some ideas. My big issue right now is caliber.

You see, everything I seem to read about the .300 AAC Blackout says it's superior in almost every conceivable way to the 5.56. The only real drawback I've read about the .300 BLK is it has a shorter effective range than the 5.56. Since I'm not looking for a gun that's accurate out to more than 200-300 yards, it didn't seem like a drawback.

But something is nagging me. There's something in my gut that tells me I'll regret going .300 BLK. And maybe you guys will be able to help me with it. Let me explain what I'm thinking about this build.

1. I don't know if I want to suppress it or not. Though if I went .300 BLK, I'd almost certainly get a suppressor for it in the future.
2. I began thinking that if I did suppress it, that it made the most sense to build this as an SBR to keep the overall length down (and since past about 10" there's little advantage to additional barrel length in the .300 BLK).
3. I don't really have a good reason to have a suppressor except that I think they're cool and the idea of being able to shoot it without ear protection is enticing.
4. I have the ability to reload, and I would be confident in my ability to make .300 brass out of 5.56/.223 if I needed to, so ammo cost is only a small consideration.

If you need more info to help me out, please ask. Chances are, I'll probably eventually make 2 uppers anyway, so this is really just to answer what I'll build first. Going the SBR/suppressed route essentially adds over $1000 to the cost and that might be enough for me to just go 5.56 off the bat. Anyway, thanks for all the help.
 
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madmo44mag

New member
Great thread Gaerek.
I'm kinda in the same boat as to build a 300.
I wait to see the comments myself.

I like the round just because of it's size and the reloading challenge.
Do I need it - NO
Do I have a Used for it - NO
Should I build one anyway ???????????????:confused:
 
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MarkCO

New member
I had one customer go .300BLK for his first AR...sold it a few months later. It is good for a 2nd or 3rd if you have a need or want for it, but I still would not put it in 1st place.

First, ammo is more expensive, second, they can be a little more tricky to get running, third, if looking short barrel, there is a bit more to hitting out at 300 yards than the .223.

I say build yourself a good mid-range .223 carbine and shoot the snot out of it for a few months. Acquire the parts for the .300 and build the upper once you have that down. If you reload, save some brass and you can send it off to Hoser Brass to get it made into .300BLK for about .10 each.

I have a 16" BO and a 10.5" BO. I went the path of the pistol with a SIG cuff for the 10.5. All the benefits of an SBR, but no $200 tax.
 
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Gaerek

New member
Yeah, in the process of writing my OP, I practically talked myself out of it. My plan is to build the complete lower first, before worrying about the upper. I have some uppers I can borrow, so it makes sense to do that first. I wouldn't say that budget is a primary concern, but I do know if I went .300 BLK, I would go all out with the SBR and suppressor. Basically, it would make the upper go from a maybe 4-5 months (spreading purchases out over time) to over a year to build (due to the same constraints plus the bureaucratic red tape). If I just go with the 5.56 upper, I can get the ball rolling on the SBR and suppressor and be shooting the gun while I wait. Either way, I'm terribly excited about this build. :D
 
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shooterfpga

New member
You can get a 300blk for under $700. If you decide to build one, even better because you can throw in whatever parts you would for a 5.56 build and if you dont like the 300blk just buy a 5.56 barrel and sell the 300blk. Also, theres a video on youtube of 300blk making 1000yd hits.

Off the top of my head if i remember correctly 300blk is only 5% better at 500yds.
 
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MarkCO

New member
SIG Cuff on a .300 BO pistol.

300BOP1_zps0d06a081.jpg


Here it is on the SIG website: http://www.sigsauer.com/SigStore/sb15-pistol-stabilizing-brace-552.aspx

The ATF says it is an accessory, and not a stock, but there is nothing that says you can not fire it from the shoulder. Depending on what pistol buffer tube you use, it can rotate or slip off. I use the ACE pistol tube and the adapter has a threaded hole on each side. I put a rail on one side and QD sling pocket on the other. One wrap of hockey stick grip tape, and it is nice and stable, but I can still pull it off if requested.
 
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sailskidrive

New member
4. I have the ability to reload, and I would be confident in my ability to make .300 brass out of 5.56/.223 if I needed to, so ammo cost is only a small consideration.
Click to expand...

I think the 300AAC is a great second or third upper; but the ammo availability really sucks. Granted you said that you don't mind forming your own brass, but having to do so simply because you can't easily find any factory ammo is a PITA and not exactly what I would consider "general availability".
 
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Ibmikey

New member
Commercial ammo is available from many sources for 300 BO from ok to terrible in price. I bought 500 converted cases and dug 1500 pulled 147 gr bullets off the shelf that I bought 10 years ago and now I am rolling out plinkers to fit my shooting needs and back up ammo to go on the shelf. The Blackout is a lot of fun and cost me nothing more than an additional Rainier barrel as I was building another 5.56 when the midstream change occurred. I only shoot supersonic and am very cautious that all Blackout ammo is visually marked so it does not end up in a .223.
So obviously I like the 300 BO but it would not be my only AR, and is not. Also one cannot have enough firearms without M1 Garands, Carbines, 1903 Springfield's, 1917, Krag and a trapdoor carbine......it just ain't American! (Better add a few 1911's also).
 
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Gaerek

New member
I think I've pretty much decided to just go with a standard 5.56 upper for my first build. I'll do a full 300 BLK upper later. My reasons are cost and time.

I know the extra cost for the build can be essentially negligible, but I'm the kind of person that wants to do things the right way the first time. That means I'd be doing a suppressed SBR if I went .300 BLK. That'll add around $1000 (low balling I think) to the build and about a year (due to increased cost and red tape). It'd be nice to just have something I can shoot sooner, then work on my upper later. Plus, since I can reload .223 also, I can have cheap plinking ammo even when I have the .300 upper done. Thanks for the input everyone. Once I start and when it's finished, I'll be sure to post. Though I probably won't be starting until May or so I think.
 
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trg42wraglefragle

New member
The second post had it spot on really.
5.56 will be cheaper to feed, as well as a heap of bullet weights to choose from for different purposes, and effective range is a lot better.

Unless I was going to suppress it, I wouldn't bother with 300BLK.
It may have more energy up close but usually in the ranges 5.56 is still more than effective. And after that range 5.56 will carry energy a lot better, with less drop. BUT 300BLK works well suppressed.
 
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tahunua001

New member
You see, everything I seem to read about the .300 AAC Blackout says it's superior in almost every conceivable way to the 5.56. The only real drawback I've read about the .300 BLK is it has a shorter effective range than the 5.56. Since I'm not looking for a gun that's accurate out to more than 200-300 yards, it didn't seem like a drawback.
Click to expand...
there is also the consideration of more wind drift with a fatter slower round like the 300 blk. you may not have an overly critical difference in bullet drop to 300 yards but adding wind drift will also make it more difficult to score a hit when you have to factor in more windage and holdover.

the here's the deal that I see. 223 from an AR is loud as hell, that is the first suppressor I would get if I wanted one. 300 may have been designed with suppression factoring into the thinking process but that also means that the audible report to begin with is lower than 223, if you hunt with it or forget hearing protection in the mean time before your paperwork goes through(2 weeks ago I was told that people's paperwork is taking 6-9 months to be processed by a local suppressor dealer) the 30 is going to be a lot less detrimental to your hearing than 223. hmm... I originally intended that to be an argument in favor of 223, but it seems to cut both ways.

lastly, a suppressor adds about 6 inches of length. a standard carbine length rifle with a suppressor is still shorter in orverall length and less front heavy than a heavy barreled target AR. this is just my opinion but making an SBR because you MAY eventually want to suppress it is like neutering your rifle's long range capability and accuracy while spending lots of extra dollars in the mean time. in the end you still have to spend a good $500-700 for a decent supressor and fees before you end back up with a normal length rifle that is quiet to shoot.
 
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jmr40

New member
The 300 seems like a step backwards to me. The only conceivable advantage I can see is as a suppressed weapon.
 
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Gaerek

New member
As I said, I'm going with the 5.56. My main reasons for thinking about a .300 BLK are they can use the same mags, bolt, etc, I can make ammo using .223 brass, and I'd like to suppress it.

But being my first AR, I think the best thing is to just build it the way it was intended, at first anyway. Once that's built, I can decide if I want to go .300 BLK or not. I still think it's a cool round. Definitely not as versatile as the 5.56, but certainly fills an interesting niche.
 
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doofus47

New member
Jmr40
The 300 seems like a step backwards to me. The only conceivable advantage I can see is as a suppressed weapon.
Click to expand...

I'm with Jmr40.
I have a 7.62x39 upper and it works fine enough.
The advantages that I see of 300AAC over 7.62AK are:
1. 300AAC feeds more reliably out of the box. I've dialed in my 7.62AK by adding feed ramps, so... that's a wash for me.
2. Can buy "surpressor-specific" box ammo for 300AAC. This is good as I don't reload. But I don't have a surpressor either.
3. Better ballistics in 300AAC, but both .300 rounds are inferior to 6.5Grendel or 6.8 SPC. Either .300 round will kill a deer within 150 yards which is what I'm looking for.

If you want to go short barrel/surpressor, I'd buy a 6.8. Not that I have anything against 6.5G, but for a build with those specs, but I'd go 6.8.

My 2c.
 
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Bartholomew Roberts

Moderator
I own a .300 SBR and a few 5.56 ARs. If you are going to build a 16" rifle, the .300 loses a lot of its attraction. It still has a role if you are looking for a semi-auto brush gun and not comfortable with .223; but .300 really shines as an SBR/pistol.

Someone else mentioned 6.8 as an SBR; but 6.8 will be harder on short barrels and suppressors due to its genesis and you'll need a different barrel, bolt, and magazine to approach .300 reliability - and you won't have the easy suppressed subsonic option that .300 provides.

If you have to have a 16" barrel, then you might as well take advantage of it, and .300 isn't the best suited for that.
 
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Justice06RR

New member
Looks like you made up your mind. I agree you need a 5.56 AR first before you go with a 300BLK. A 300BLK upper will be easy and cheap enough to build after you have a complete 5.56 rifle.

The 300 seems like a step backwards to me. The only conceivable advantage I can see is as a suppressed weapon.
Click to expand...

People really need to understand that 300BLK is not meant to replace or supercede the 5.56NATO.

300BLK serves a different purpose; CQB and Suppressed use.
Consequently it still works good unsuppressed and in rifle(carbine) form. The added advantage is using 5.56 parts except the barrel.
 
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