What do y'all recommend? Shots about 70 yards or less. Running a suppressor is completely new to me, so are AR platforms. Do I need to change the recoil spring to use subs?

This is the one I’m going to use with an omega 300

With 220 gr your good (50 zero) to 50, then 6" drop @ 75. I shoot 110 to 150gr in my BO 10" pistol, not subs. You are not restricted to subsonic with a can. 180gr cast are fun @ 1400 fps and decent acuracy. UMC or Hornday makes decent BO ammo.

I keep some expanding subs loaded for home defense. But for hunting, I switch to 125gr SST's. IMO, 125gr SST'S are the perfect 300BLK bullet. If you don't handload, Fiocchi loads them.

Dallas Reloads with a Maker Rex bullet is the best I have found and I’ve killed a bunch of pigs with it.

I have used a 300 blk out for many years hunting in AR's and in bolt guns. The best bullets I have found for the blk out is the 125 grain hunting bullets. The 125 SST (favorite), 125 grain TNT, and 125 grain Ballistic Tip have all performed very well. The 110 V-max would do ok in the shorter barrels also.

For subs, the heavier the better. I have the 200 grain Maker expanding sub that is a really good one. The 190 SUB-X bullet is ok, and you will get "some" expansion. For the lower cost, the 208 A-Max is hard to beat (I also have it on a reduced price). I have a 280 grain expanding sub I still need to load for. That would be awesome!

What Chad said. I use 125 Nosler ballistic and 208 A max in my 10.5” SBR and Silencerco Omega. Took me awhile to get both to run well with an adjustable gas block but found the sweet spot.

Thos 125 SSTs are rare as hens teeth.

Loaded ammo or components. Easy to find online. I just bought 500 bullets a few weeks ago. ammoseek.com

We killed 4 pigs this weekend with my 10.5" blk out with 125 SST. Dropped em all!

I have THOUSANDS of the 125 SST in stock for the blk out (and 308 Win).

I got about 50 SST left, 200 vmax and 100 ftx loaded. Winfield outfit has them at 50$/100 plus shipping. Not sure I really need them. They do work good.

Our load for the 300blk is some bullets from Midway those were rejects that they had on sale, picked up
208 and 212grn bullets, Run AA 1680 10.8 grns little more then your getting into non sub sounds! im not
using ear muffs on head, pretty quite out of blind! fair groups, b ut im not shooting 200yds either.
Tagged a big sow back in May, hit her right almost ontop of her head, pretty close to the ear, she dropped
like a rock, couldnt find the bullet but i was impressed with the low velocity.

My tip is shot placement is paramount,

Also, tried with or without suppressor, the group didnt vary much, so im happy!...
Aero lower, PSA 16" upper, works for me....

All good comments, but if the main reason you want to use subs is to prevent scattering of the sounder at the shot, this usually does not work. The hogs scatter with the sound of bullet impact on an animal (or object) in most cases.

This has been my experience. And even using supersonics, they scatter, but they don't necessarily run directly away from the loud noise. I've even had some that were running directly away from me headed from the field to a woodline, I shooting at them, when they suddenly turn around and come running back into the field. I assume it's because the bullets hitting the trees in front of them sends them back around.

Agree.
I've been using a 300BLK on hogs for over ten years now. Originally I thought I'd use subsonics and pick them off without them knowing what was going on. That never worked. Even suppressed, the sound of the rifle shot is pretty loud, and the THUD of a round hitting a hog (or the hog squealing if the bullet doesn't penetrate both lungs) quickly alerts the others. I switched long ago to Hornady 110 grain SP bullets. I've used the 110 grain VMAX when the SP bullets weren't available but didn't really see a noticeable difference on the hogs.

OK, this was silly. Sitting on my ATV, 5 hogs at the feeder (50 yds), Rattler IR on BO pistol. Sorry NO vid (to avoid getting laughed off this site), 6-7 shots, 110 vmax ~2100 fps., no 'muffler'. Missed ALL! Hogs kinda turned around, looked my way and wandered off into the brush after I gave up shooting. After a SW upload that fixed retical boresight problem, shot at 2 small hogs 100yds - missed by an inch. Yes, saw the bullet skidmark in the dirt. Unless you MUST be 'silent', use supers. I have shot 170PB abd 185GC out of this rig but about 1400 fps. But it was just cheap plinking.
So, MrWood is going to pay for 2 Fed 'tags'. How about a true pistol vs SBR and no muffler?

I've heard that it happens. Never happened to me though. I am a MUCH better shot than that. I've never missed before...

Out of the box the Rattler needed to be zero'd for each retical - I inadvetantly changed reticals. SW update fixed that. Actually that update fixed the retical thing but locked up the scope. Next U.D. all OK. But it was weird, I'm blasting away at hogs from 50 yds and they didn't seem worried at all. Or laughing at me? I was ticked!

Lehigh Defense 198gr Controlled Fracture kills them FAST !!!