AR15 Caliber Change for Deer Hunting

[OSOK]

Just want to pick everyone's brain a bit. I have a standard .223 AR and I want to switch barrels to a better deer hunting caliber. I was just wondering which caliber everyone thinks would be best? 6.8, .30 AR, .300 AAC, etc...

[OldSchoolRanger]

I would have to go with the 6.8SPC II.  Don't have any experience with the other calibers, and have yet to actually see a Rem AR.30, as a matter of fact, the question begs to be asked, is this caliber still in production?

[Dee]

I would check on ammo availability for all, and the cost of that ammo. On the other hand, the 223 will do the job.

[Lloyd Smale]

ass said the 223 can get it done if your careful about bullet selection. Next step up are the 6.8, 30rem and 762x39. All three are close enough in power to make it about a non issue. I went with the 762x39 because cheap plinking ammo is available, brass is easy to find to handload with and i can go out to camp occasionaly with some steal cased ammo and blast away and not have to worry about digging the brass out of the deep grass

[Dezynco]

Any of those will work, and the 223 you already have will work in a pinch.
You didn't mention some of the others that are available,  6.5 Grendel, 450 Bushmaster, 50 Beowulf, 460 Rowland, 338 Specter, 300 Olympic, etc

I would go for availability of ammo if I were not a reloader, the 6.8 SPC, and 300 Blackout are pretty easy to come by these days. 450 bushmaster and 6.5 Grendel are pretty easy to get also. The "wildcats" would be for me only because I load my own ammo.

[Lloyd Smale]

Ive got a beo too and its accounted for a couple pigs and a water buffalo but wouldnt be my first choise for deer hunting if the range gets much over a 100 yards. Sure puts the smack on things up close though.

[Cemo]

I have a .223 and although I never shot a deer with it, my young Nephew shot four deer using the .223 Federal Partitions and they never went far. I decided to start using the AR for deer hunting this year. Most of my hunting is in woods stands where you can't see much over 100 yards, but I do have a few small fields where a 200 yard shot could present itself. My initial selections were the 7.62X39, 300Blk and the 6.8. I had a Mini-30 and have a CZ carbine in the 7.62X39 and know it to be an excellent round for the woods. The 300Blk has similar balistics to the 7.62X39 and is a better choice for the ARs, or so they say. I found a site on the net, 68forums.com, where people were discussing their experiences with the 6.8 Rem. The 6.8 offers a litte more range over the 7.62 and 300 so I elected to go with it, just incase my hunting opportunties changed. Meanwhile my buddy bought an AR in 300Blk. for deer hunting. I am very satisfied with my 6.8, but after shooting it and the 300Blk side by side, I think I would really be happy with either.
For an AR conversion, the 300Blk only requires a barrel. The 6.8 requires a barrel, bolt and mags.

[Dixie Dude]

From what I have read the 6.5 Grendel is better downrange than the 6.8.  Problem is Alexander Arms kept it priority and wouldn't let anyone copy if for several years.  They recently released it.  If anything other than .223 or 7.62x39, ammo is not so easy to find, and is more expensive.  You can still buy cheap .223 and 7.62x39 in bulk.  If you need more than 100 yards, the 6.8 or 6.5 is the way to go.  Under that a .223 with a good Partitian or Barns TSX will get you more penetration on bone.  That being said, I have a friend who shot a 9 pointer with a 44 mag Ruger carbine at measured length 192 yards.  His dad saw him do it and couldn't believe he did it.  My friend aimed about a foot high to hit him.  He was a teenager at the time, and now he says he wouldn't take a shot like that for fear of wounding him and not finding him. 

[Larry L]

Assuming that you reload, take a look at the 6x45. It's a real simple cartridge and cheap to load for. All you have to do is run 223 brass thru a sizing die and load it. It's the 223 case necked up to 6mm. No expensive extra clips to buy, no clip capacity lost, no expensive brass, no tricky bolt face to buy, and accuracy is near benchrest. The military used this cartridge for a short time for snipers. The advantages are sending a heavier bullet down range than a 223. Here's the data:
http://buckammo.com/Images/6x45_loaddata_1_2.pdf


There's also a .25x 45 which is the 223 necked up to 25 caliber. It's also well documented as being extremely accurate. FWIW, my 6x 45 shoots the 70gr TNTs at 3100'ps which makes it a great varmint load. For deer size animals I'm using the 80gr Remington that comes out of mine at just under 3000'ps which is not all that much slower than a 243. I'm using a common Stoner stainless barrel from Midway 20" 1:8" twist and have shot numerous 1 hole groups at 100 yds with it. If you know how to swap AR barrels, the barrel is all you have to buy-$219.99. If you don't know how, takes about 15 minutes and a caveman can do it.

[Dixie Dude]

6mm is about 243 caliber, actually .236, so you might could use 243 bullets.  Haven't heard of this, but is interesting.  Can buy an upper without changing the bolt or magazines.  Smaller case if using the 223 case, but loaded a little hot, would be better for deer than 223. 

[Lloyd Smale]

If i had to choose a deer hunting ar15 and thats all it would be used for id probably go with the 25wsm. It easily gives 257 roberts power level and with some loads 2506 level performace out of an ar.

[SharonAnne]

the 6.5 Grendel is no longer a proprietary round. It is now a SAAMI round and Hornady is loading ammunition and making brass available.