300 Blk vs 308 AR question

[osteodoc08]

I have a few 223/556 ARs and a 308 AR on the way. I have the opportunity to buy an AR in 300 Blk from a friend that just never shoots it. I really don't see it doing anythingy current 223/308 set up does, but I'm not that familiar with it. Does it stand on its own merit and is it worthy of the brass/die investment or a passing fad?

[5Shot]

Only if you have a can and shoot subsonic

[Springfield]

Or live in California and can't buy any more large cap mags, and currently own a few. Or want something larger than a .223 but don't need full .308 capability. And you can make brass out of .223 brass, which is easy to get.

[Quiettime]

It's very similar to having a 7.62x39 AR 15, not quite as powerful at the muzzle, but with a lot more bullet choices and more versatility as it is made to shoot sub-sonic. I.E. true cast boolit AR. That's why I built one, to shoot cast out of the AR.

That said it can be a real PITA to get the thing to cycle sub loads reliably. You have to enjoy tinkering with the gun and the loads.

If you intend on shooting mostly factory ammo, I would not really recommend buying a .300 BLK. Factory ammo is way overpriced IMHO

[Jbiker]

the ballistics' are close to the good ole .30-.30, great for pig hunting ,there are a lot of load's / data starting to appear. brass is makeable out of 223 cases, and the m80 /147 gr nato pull's are pretty cheap for plinking. powder wise yer sort of limited 1680,lil'gun ,H110 , 4227, N110,and a few others. the Lee 230 cast bullet is a great sub bullet and can be run up to 1400-1600 fps. the upper will fit just about any ar lower you got, just another fun caliber to work with . my 2 cents.

[Quiettime]

brass is makeable out of 223 cases.

That's the other reason I built one. I have a lot of .223 cases and the conversion process is, I think, kind of fun. You can also use blanks or cases with the mouth cracked or damaged.

Be advised however that some .223 brass works and some does not because of varying thicknesses. I've had good luck with most American commercial brass and Lake City 5.56 brass, although I find the LC to often have oversize rims, but I came up with a solution to that too.

[popper]

Lee die set is low $. Hard to download the 308 & still cycle. Bigger hole than 223, 15 gr. of powder.

[osteodoc08]

I have 308, 5.56, and 300BO. The 308s are in bolt platform, and the 5.56 and 300BOs are AR15. Since I shoot cast exclusively these days, the 300BO loads and 308 loads are very similar velocity with the same boolits. My pet 308 load is 19gr 2400, but in the 300BO I'll use 15.8gr H110. The boolit is the Lee C312-155-2R sized .311" and averages 1875fps from the 308, and 1920fps from the 300BO.

Does it cycle your AR?

[ipijohn]

the ballistics' are close to the good ole .30-.30, great for pig hunting ,there are a lot of load's / data starting to appear. brass is makeable out of 223 cases, and the m80 /147 gr nato pull's are pretty cheap for plinking. powder wise yer sort of limited 1680,lil'gun ,H110 , 4227, N110,and a few others. the Lee 230 cast bullet is a great sub bullet and can be run up to 1400-1600 fps. the upper will fit just about any ar lower you got, just another fun caliber to work with . my 2 cents.

I got one to go with my 5.56 so I will have a semi auto that is easy to load with lead and will shoot in 30 cal the next time reloading/ammo supplies get short. I know I may be predicting doom, but it has happened more than once in my lifetime. All of my other center fire rifles are bolt, lever, or break open.

[andremajic]

Love the 300 BLK. The things I look for in a caliber is availability of components.

First of all, you will always be able to find used 5.56 nato brass or .223 brass, and you can use the whole range of commercially available .308 projectiles, not to mention cast.
Uses small rifle primers, and is super stingy on the powder. Because the case capacity is smaller than, say a .308 you don't need to worry about a lot of empty space for your subsonic loads.
A pound of powder lasts you a lot longer, and this caliber is even better than most, because most of the loads use fast burning pistol powder, like red dot, H110, trail boss, etc, which brings a lot more versatility and options to your table. Since you can buy red dot in 8lb jugs, it's not hard to get a decent supply on hand.

.300 BLK isn't really what you'd call a "fad", because it's been around since the 1960's when it was known as the 300 whisper.
I haven't owned a .223/5.56 Ar-15 in over 10 years, and I don't miss it either.

Oh yeah, and having a 30 round AR-15 magazine loaded with 30 rounds of 30 caliber ammo is a big bonus too.

my .02

[5Shot]

I would agree with all the above, but one would have to think long and hard as to whether it was worth the investment if you were already set up for 308 like the OP.

[ipijohn]

I would agree with all the above, but one would have to think long and hard as to whether it was worth the investment if you were already set up for 308 like the OP.

I have 308, 30-06 and 30-30. I got one since I already had everything I needed to reload except powder and dies. And like I stated previosly my other 30 cals are bolts or levers. It is also good to have 30 round mags for something 30 cal.

[osteodoc08]

Y'all are really making me like this cartridge. I had another buddy of mine trying to sell me on the 6.8 SPC. I can do more with my Sig 716, but the 300 BLK really seems to "bridge the gap" more effectively perhaps? May have to pick this one up.

[dragon813gt]

I think the 300 BO is better suited for a bolt gun for suppressed shooting. No action noise but of course it's not a semi. Ruger is releasing their American Ranch rifle soon. I will be picking one of them up. I also have an AR lower on the way that will be registered as a pistol. Just wish the short uppers weren't so much money. For me I would only want a 300 BO AR if it was a short barrel and suppressed.

[xacex]

Only if you have a can and shoot subsonic

Really? Do tell me your experience with the round. Maybe I am missing something shooting supersonic out of the three I have here. The deer I got last year with a supersonic round out of 8.5" pistol sure couldn't tell the difference from the 300 Blackout, 30-30, or 308. I could sure tell the difference in the cost of making the ammo.

[Quiettime]

Just wish the short uppers weren't so much money..

Yeah no kidding, and the factory ammo is more expensive than the 5.56 it is cut down from. Kinda like when they had to "take the lead out of the gas" making it more expensive :groner:

I lucked out and traded a 5.56 barrel to a guy for a Noveske 8.2" with gas block and tube, one of the few times I really feel like I got the better end of the trade!

The damn Sig Brace is way over priced too but it's a lot better than just a tube sticking out there

[Quiettime]

Oh and the American Ranch is on my Christmas wish list too, hope they show up soon. Stock is butt ugly though, maybe Boyd's will come out with one for it...