300Blackout For Deer Hunting

I think ammo selection is ultra critical for it.

Personally, I think .223 with the right ammo is a better option if zero recoil or an AR is the reasoning. The much higher velocity should give more consistent terminal performance and the ammo options are better.

Read the thread ".223 for bear, elk and moose" on rokslide.com

Don't burden the kid with a off-brand caliber just because you think it is cool.
Stick with something widely available that he can readily purchase in various loadings and utilize throughout his life.

I like the 6.5 Grendel better than 300 blackout, but it is also going to be dependent on proper bullet selection.

I haven’t been able to do much testing yet but I’m happy with the performance of the nosler ABLR on the one deer I’ve killed with it.

Do it. That way when he out grows it, you can throw a thermal and suppressor on it.

I have one for my son. He is 8, but he has been shooting it for a few years.

Killed 2 last year with 110gr Barnes. Dead within 20 yds, no blood trail.

I've killed a couple dozen deer over the last several years with subsonic 300blk.

im sure i could reload some.

Works fine.
As someone pointed out, similar ballistics to a 30-30.
I have one set up in a contender w an 8 inch barrel. Another in an AR platform.
My kids used the AR quite a bit when they were younger and I used the pistol several times too.
All told, prob 13 or 14 deer w it.
All shots within 100 yards. All kills. All dead in the spot or short run.
Bullet choice is important, but with the popularity of the cartridge, I think a good choice for kids.

I've had good results on pigs w/ the fiocchi 125gr sst in 300bo - usually isn't too expensive for these rds. Makes a large hole in them. I've used Barnes w/ great results as well.