I’m planning to deer hunt some with my AR. I wanted .300 Blackout but “settled” on a .223 Wylde when I couldn’t find the .300 upper I wanted. I may be overthinking this. I know .223 ammo is better than ever. Should I sell the .223 upper and get a .300?

life is too short to only have one or the other, you need both.

Don't over look the 7.62x39. This has quickly become my favorite AR I have. It's a toss up between it and the Grendel.

I don’t understand the question. Why would you sell the 5.56 upper to buy a 300blk, or other upper? If you don’t have another $300 you can’t afford to shoot either one. Seriously, keep the 5.56 for varmints and plinking. Get a 300 upper(16” if you are putting it on a carbine/rifle lower) over the summer as funds allow.

7.62x39...

Prolly the right answer. Ain’t like I’m hunting next week...

Both

^^^^all that^^^^

And go ahead and get the .300bo with a 9" barrel and suppressor, and slap it on a pistol lower with a "brace" (wink wink)

keep the .223 upper and buy a 300

That pistol barrel on a 300 aint the greatest for deer (imo). Keep it at 16” and its better. For hunting, can still run the can fine. Imma kill one next year with mine. And maybe my 556...

Yeah. I’m not playing pistol. I like 16 & 18 inch barrels.

You can certainly build whatever you prefer, but simply in terms of accuracy, a 300bo gets its maximum power burn in 9-10" of barrel. There's no real advantage of a longer barrel than that. So take a 9" barrel and slap a suppressor on it, and your overall length is still in the 16" range, WITH the suppressor. Slap a 12-15" handguard on there and you're ready to rock and roll. The only downside is you are still technically shooting a pistol, so it has to have a pistol lower, with a "brace", but hell now they got "braces" that are 6-position just like a regular stock. That whole thing is a joke.

this.

There’s nothing wrong with a pistol length barrel for 300blk. In fact it is preferred by most to wring what “benefits” there are in that particular cartridge out of a weapon. But the idea that barrel length effects accuracy is a myth. It does not. There are 9” barrels that will shoot 3/4” groups and others that will shoot 3” groups with the same ammo. Sight radius may come into play if the user is relying on iron sights but that can be mitigated with a reflexed handguard (assuming you are only running it with a can). Of course that can is going to add another $600 or so and a years wait to your build. It is true that, in general, all of the powder is burned in the first 9-10” but you’ll gain about 25fps velocity per inch of barrel out to about 18” and then 5-10fps out to around 30” if I recall correctly.
If you intend to hunt with subs and a can, a 7-9” pistol is all you’ll ever need. If you plan to use supers most of the time then 9” is also fine but going out to 16” will extend your effective range with premium bullets. The difference between 150 yards and 250 yards is moot if, like many, you are looking at the 300blk for very short range hunting. Until you’ve found yourself with an opportunity at 225 and you just don’t have as much ‘ooomph’ as you need with what you are carrying.

i love my 300b0 with 10.5" barrel. I can ring a 6"steel out to 300 yards. I love my 55.6 for the cheap ammo. So my suggestion is keep the 556 for a main battle rifle that could still be used for hunting. If you want a BO, i would suggest the 10'5 with sba3 brace. It reduces weight and the size makes it easier to handle, to me the supersedes the small gain from longer barrel, considering most of my shots will be 175 yards or less. If i need to shoot deer at a longer range, I would go with a different caliber the bo or 556.

The only problem with the 7.5 inch and 9 inch barrels is you are only going to get one twist and that can affect bullet stability. For short range that isn’t a problem. But, the longer the range, the more it come into affect.

This is what i was thinking. Friends son shot a doe at less that 50yds with subsonic 300bo pistol and got terrible results even with good accuracy. Was shooting premium ammo too.

Hunting with subs is bow hunting with a firearm.

With a field tip, no less.

Makers and Lehigh open up like expandable broadheads. They are also close to $3/ea for the bullets alone.