All set up to load 300 blackout will be using my 10.5 upper with silencerco specwar, I'm a little hesitant as I don't want to mess up and have a baffle strike.

Right now i'm doing all single stage as i'm just learning.

Any suggestions or am I just over thinking this?

Felt the same way shooting my 16" Blackout with a new Yankee Hill Phantom Ti. Did do some inspection making sure the can was in line. Only one shooting session and about 10 rounds and haven't been able to go again. Only issue I think I may have is getting the 208 Amax to go subsonic and cycle my bolt. Don't think subsonic load data and 208 Amax with 1680 powder is going to cycle without going supersonic ?? Reloading isn't going to cause a baffle strike just a loose suppressor or misaligned one.

I always fire a few rounds at 25-50 yards to check for tumbling before I put the can on.  You should also visually check alignment first too.

Shot my rifle a couple weeks ago, I understand the misalignment, first time I put my can on I broke it down and noticed is was significantly off, had I not checked it wouldn't have be good.

Guess I'll just need to double check all my specs.

Still deciding on the 208 gr Amax or 220 gr Sierra match king.

This.

What bullet/load?

If your barrel isn't from a reputable manufacturer, you might want to have a smith check the concentricity of the threads to the bore, if you're concerned about it. What twist is your barrel? As others have said, if you're worried about stability, put some through paper  without the can on, and if they're tumbling, you'll see them going through the paper off-center (the holes won't be round). If you have pistol length gas, AA1680 and IMR 4227 do just fine at cycling the bolt with the can on while shooting subs. Loading subs is a little different than you're used to - you start with a known safe load and work your way down until you get reliably subsonic and reliable cycling. Carbine length gas makes things a little more iffy, but I don't seem to have problems with either powder with the can on either. Supers will always cycle the bolt.

ETA:208 Amax generally works just fine. As you go below 200 grain bullet weight, it becomes more difficult to get cycling at subsonic velocities/pressures without a lot of adjusting. I use Palmetto Projectiles' 203 grain powder coated lead rounds (which requires flaring the case mouth like a pistol round to prevent shaving lead) for practice on steel. They work very well, and are very low cost.

AA1680 and 208AMAX are a great combination.  It's going to be 10.5-11.0gr seated at mag length.  Start at say 12.0 and load down in .2gr increments until the supersonic crack goes away.

What barrel length, gas system length and twist rate do you have?

I ask because I have a 16", 1:7 with a carbine gas system and I struggle to get it to work with anything less than 220gr pills in subsonic. It shoots 220's like dream of silent death though.

I tried to use the Palmetto projectiles 203gr coated bullets and I just couldn't get them to cycle subsonic reliably even with A1680. I am going to religate them to my break action/Bolt gun team.

I would suggest buying an array of bullets and trying them in small batches to find what your gun likes. but try everything from 190's up to 240's.

I use AMax 208s with 10.7 to 11 grains of Hodgkins 1680.

Stays subsonic.

CMMG 8.5 inch barrel, pistol length gas, YHM suppressor

Whoosh, thud

I just bought an 8.5 pistol gas and I am really looking forward to having many more options open to me.

Thanks NoHarmNoFal. May have to try some 220 grain bullets as I don't think my 16" carbine is going to go subsonic and cycle.