.223/5.56 vs 300 blackout on an Ar-15

Discussion in 'Caliber Zone' started by Jed, Dec 29, 2014.

  1. Not looking for a caliber can of worms but.....

    I am building a home built AR-15 platform. Look to mostly do some target shooting with it and maybe a little hunting (deer and feral hogs). I am looking at two possible uppers, either a 5.56 or a 300 blackout. Looks like the price on the uppers is comparable and the ammo runs about .50 per for 5.56 and about $1 per for the 300 blackout.

    So which way would YOU go? And Why?
  2. Fracman

    Fracman Member

    I bought both. I have found that my 300blkout likes the hornady custom ammo I have not played with it much. I have suppressed both of them. Will play with them more this summer

  3. FlashBang

    FlashBang I Stand With Talon Lifetime Supporter

    If you can swing it, go with both. It is just as cheap to buy an upper anymore as it is to build it from parts. I roll my own handloads so the cost is not much different for .223 vs .300 BLK.
    The .300 BLK will suppress much better then the .223 will.

    I buy uppers from the below folks, shipping is fast and free. I have an 8.5" and 16" .300 BLK upper from them and they are very good uppers. ( I am not affiliated with them in anyway )

  4. I am in CA, a suppressor is really not an option. Would be fun for the foxes going after my chickens, I would not have to wake the neighbors at dawn but in CA.....

    Having both would be nice but at the moment only one new riffle project is in the cards.
  5. Think1st

    Think1st Supporting Member

    Some people shoot feral hogs with 5.56, but it takes some really careful shot placement. .30-cal rounds tend to be the most consistently effective. With that in mind, you may want to go with a 300 Blackout upper.

    If you are going to be doing only a little hunting and a lot of plinking, the 5.56 upper is probably the better way to go. You'll get the most utility out of it. You can then get a 300 Blackout upper, later on, in preparation for hunting.
  6. I'm looking at building a AR also, I spent some time debating this with my self but in the end I choice to go with the 5.56.

    I like the 300 black out it seems to out preform the 5.56 in most areas but the reason didn't pick the 300 is I would always fear a family member would mix up the rounds and put the wrong one in the wrong gun. I'm 99.999% sure I wouldn't but its a risk I won't take with my family. Now I have thought about switching everything over to the 300 and that might happen.
  7. If you reload I'd say the 300 blackout otherwise just get the 50 Beowulf :)

    Tho your definitely gonna want to reload and probably cast for that, but it will be glorious!
    Last edited: Dec 29, 2014
  8. FlashBang

    FlashBang I Stand With Talon Lifetime Supporter

    A 300 blackout round won't chamber in a 5.56 unless the bullet is pushed back in the case due to not being properly crimped, or the COL is to short, and will keep the bolt from going into battery. If you are loading your own you need to be very careful and inspect every round you produce.

  9. greg_r

    greg_r Lifetime Supporter

    I have both. If I had to choose it would be 300 blk. That said, you need to ask yourself a few questions. First, do you reload? If you don't, and are going to target shoot a lot, 223/5.56. The 223 is actually a pretty good hog gun if you place your shot well. Hogs seem to me to succumb to 223 quicker than most animals. Use a premium bullet though, now you are up to the cost of 300 blk if you don't handload.

    The 300 blk is more accurate, it will do one MOA all day long, my 223 is about 1 1/2 MOA. At least in my rifle.

    My 300 blk has never fired a factory round. I generally buy bulk 223 then form 300 blk from some of them when I reload.

    The 300 blk is also a fine hog round, if you go supersonic. I use Nosler 125 gr. I use the Hornady 208 gr for subsonic, but you have to remember that they are a bit less than 1/2 as fast as the 125's
  10. bscar

    bscar Supporting Member

    Simple solution, buy more AR15 mags and label them with white out or some kind of marking that says they're .300blk or 5.56. This way you'll keep your loaded mags separate. Do the same with the uppers and you should be good to go
  11. Back2School

    Back2School Member

    I got some black and some Dark Earth. I keep .223 in one 5.56 in the other. I know I dont need to, but it helps me keep them separate like i want them to be.
  12. bscar

    bscar Supporting Member

    Since AR mags are dirt cheap, it shouldn't be a problem buying more. I've seen some on sale for like $5 each
  13. wganz

    wganz Supporting Member

    Use the 30 round magazines for 5.56.
    Use the 10 or 20 round magazines for .300.
  14. VinnieD

    VinnieD Member

    I'm considering putting together an alternate .300 upper myself. Although you can get away with only changing the barrel, it's enough of a PITA to do that it's probably worth it to pick up an extra stripped upper and assorted small parts to build a separate upper for quicker swapping. You could re-use the bolt carrier group and charging handle though.

    Personally I'm thinking of a 10" barrel, and a permanently affixed 6" muzzle brake to avoid having to do NFA paperwork for it.

  15. That is good to know. I had someone tell me they would chamber and that scared me.

    Thanks for that info everyone. I just bought 2 lowers last night might have to look into building 300
  16. USMC_VET

    USMC_VET Supporting Member

    How about going with a 6.8 spc upper ??
  17. Johnny_B_Goode

    Johnny_B_Goode Member

    People say a 5.56/223 is good hog round. The 223/5.56 struggles with a 200lb deer that is very light skinned. We run into 300lb hogs pretty often. A friend that has a good pack of dogs took a guy hunting with a 223. The dogs bayed a big hog. He could hear the 223 pop, pop, pop. He could hear his dogs in distress so he ran through the woods to get there. He found the hog covered in blood slinging his dogs around like a Frisbee. He shot the hog once in the head with a 308 and the hog dropped. If he had not bought flak jackets for his dogs he would have lost the whole pack. The hog weighed close to 300lb. He didn't weigh the hog. He wasn't in the mood to celebrate the hunt.

    Right now if someone wants to hunt with anything smaller than a 12ga 3" slug they are not hunting with him.

    We have a couple guys who deer hunt with an AR15. He is ready to boot them out of the club. He said not to collect dues from those boys until they get a real deer rifle. He is the president of the club. He owns/leases the majority of the land we hunt on. He oversees the care of our deer beagles. He is very concerned that they are going to wound a deer with a 223 and get some of the beagles injured. We have a lot of money in those beagles. I have bought 5 male dogs myself. I have $4,000 in those 5 dogs. (no I didn't buy the dogs all at once) But we have wonderful puppies every season. Our beagles are so well bred that we trade puppies with people who have field trial beagles. (yes our beagles walk like a field trial dog when they run a deer)

    GLUGLUG Supporting Member

    This is exactly what I've been working on. Have the complete rifle in 5.56 and just need the barrel and gas system for the 300 upper. I am going for a 10.5 bbl and a 5.5 FH. Finding a local smith who will pin and weld has been a different matter though....
  19. greg_r

    greg_r Lifetime Supporter

    Wonder what bullets they are using? I have killed numerous hogs with the 223 and found it to do a fine job. Put the bullet where it needs to be and don't use a bullet that comes apart on contact. I like partitions or all copper. Hogs have a gristle plate that can wreck havoc on soft lead like shotgun slugs.

    I like plott hounds for hogs. They are tough and can hold their own with a hog.. Like the long legged beagles for deer, and Bassett hounds for rabbits.
    Last edited: Jan 2, 2015
  20. USMC_VET

    USMC_VET Supporting Member

    Like mentioned previously how about a 6.5 grendell or 6.8 spc upper ??