8" Aero upper (pre-assembled). Lower has a Law Tactical folder. BCM BCG and CH. Lancer 300blk mags. CGS Helios QD TI can. Ammo is AAC 110gr vmax and 220gr smk. With a carbine buffer the gun runs fine with both subs and supers, and also subs suppressed. It has very strong 4-5oclock ejection with supers. With subs it's the same angle, but slightly weaker. With subs suppressed it's actually the weakest looking ejection. Not awful, but like 3-4oclock. With supers suppressed it has extremely strong 4-5oclock ejection (like 15 feet) but every few rounds it will fail to pick up another round. The bolt with just miss the rim and mash into the top of the next round. I thought it was a magazine issue, but if I swap the buffer out for an H1 it cycles fine with supers suppressed (but no longer cycles subs unsuppressed). Ejection is always extremely strong 4-5oclock with supers suppressed. I also tried an H3 buffer just because I had one and it seems to work fine, although it's pushing the limits of subs suppressed because the last round lockback is on the carrier, not the bolt. Obviously no subs unsuppressed with H3. I wouldn't run the H3 anyway, because including the 2oz Law Tactical plug, that's a ton of buffer weight total.

4-5 o'clock is not strong, that is short stroking/under-gassed.

Check gas block alignment and gas port size

https://www.ar15.com/forums/ar-15/What-gas-port-size-for-8--300BLK-dedicated-suppressed-barrel-/121-783739/

Good. Glad to hear that you are just as confused as I am.
Just to recap:

with carbine buffer (total buffer weight between h2 and h3 including Law folder plug)

subs no suppressor- short 4-5oclock. Likely barely cycling, but did cycle every time and locked back on last round. This is the lowest gas pressure condition I am giving it.

subs with suppressor- weaker 3-4oclock. Looks like my other longer AR's when I put a can on them. Potentially a little overgassed in this condition, but 100% reliable. This is somewhere in the middle of gas pressure conditions I am giving it.

supers no suppressor- longish (8-10ft) 4-5oclock. This is also somewhere in the middle of gas pressure conditions. If this were where the test stopped I would assume these gas pressures are between subs not suppressed and suppressed. But it's not where the test stops.

supers with suppressor- very long (15ft+) 4-5oclock. This is certainly the highest gas pressure condition I am giving the gun. It runs maybe 4-5 rounds and then fails to feed. Heavier buffer (H1) fixes this problem but then makes subs unsuppressed not cycle.

Now, is it short cycling with supers suppressed? Possibly, but definitely not for lack of gas. It would not work any any of the other conditions if it didn't have enough gas.

It’s definitely overgassed. The fact that it can cycle subs with no suppressor with the additional weight from the law folder means that it has at least plenty of gas and potentially excessive gas. I’m just confused about why the ejection pattern doesn’t seem consistent with normal ejection patterns. And why does the extreme overgassed condition (supers suppressed) cause a failure to feed (failure to strip the next cartridge off the magazine).

I'm not confused. Maybe Google ejection patterns.

My 8" works perfect. I must have been lucky when I tuned it.

Good luck buddy. You have a funny way of acting for help.

I’ve done quite a bit of research already and am very familiar with ejection patterns. I’ve watched my other AR’s change their ejection pattern predictably based on the tuning/conditions I give them. This is the first one that has not behaved predictably. I came here hoping that someone would have some knowledge about what is causing this. I do want help, but it doesn’t seem like you have it. Look at my results and tell me how you would plot that on an ejection diagram. Are you really going to say that suppressed supers are short cycling for lack of gas? How would that even be possible given the results of the other conditions?

I agree that overgassing is the most likely condition. I don't have an explanation for the ejection pattern but if it cycles subs unsuppressed then it seems unlikely to be anything else. You might try removing the LAW folder and using a regular buffer tube just to reduce variables, and see what that does. Personally I would pick up a YHM suppressor gas block and some number drills and open the gas block until the rifle behaves correctly. Maybe start at 0.086" and work up. If memory serves the gas port size on the Aero 8" barrels is 0.110".

I think that’s a good idea to try another lower without the law folder. I’ll do that just to see the results. Also, that YHM gas block is very interesting. I didn’t know that existed. Aero shows mine listed at .109. Curious that YHM doesn’t list the size of that port, they just say it’s 50% smaller. I don’t really want to get an adjustable gas block, but I do like the idea of adjusting it permanently by drilling. I’m going to order that. Thanks for the ideas!

If it’s cycling subs unsuppressed, you’re overgassed when you get to the opposite end of the pressure spectrum (supers suppressed), so you’re correct there.  I don’t strictly rely on ejection direction because it seems some variables between extractor/spring and ejector/spring can cause differences in how fired casings exit the upper receiver and whether or not they fully impact the brass deflector.  This can cause variations in direction of ejection, in some limited cases, IME.  

As for why you may be having the problems you’re seeing, it’s fairly common with severely overgassed guns to see bolt speeds outrun the ability of the magazine to fully present another round in the correction orientation for it to be picked up by the bolt and fed/chambered.  I’d imagine this is what you’re seeing here as the evidence seems to point towards it.

I’m a little bit confused about what you’re wanting here, though.  It seems the H1 fixes the issue, so why not run it?  Is the goal for the gun to cycle everything suppressed and unsuppressed?  If so, you may be chasing a ghost.  That’s a very wide operating envelope that will likely be less than ideal and sacrifice reliability at one end of the spectrum or the other.  I’d suggest you really examine the need or utility in being able to shoot subs unsuppressed, because frankly, it’s kinda pointless.

Just my $0.02.

At the outset my goal was to make it run everything suppressed or not. At this point though, I'm feeling like even if it's possible it might be undesirable. As you said, subs with no can is pretty pointless, so I'd like to compromise at that end of the spectrum, but currently my gun seems happier running subs unsuppressed than supers suppressed. I know the H1 "fixes" the issue, but I'm afraid that I'm going to cause excessive wear with that solution. If I count the plug from the Law folder (I think I'm supposed to) then I'm around 5.8oz total buffer weight, which seems like a lot. I'm still excessively overgassed, just slowing the action with buffer weight which I think is going to increase wear on my bolt. An adjustable gas block is the obvious solution, but I don't want one on this build. I'm going to try out that YHM gas block and manually adjust it by drilling.

And thanks for the confirmation about ejection pattern. I do have the O-ring in the ejector because it was having trouble ejecting without it. Maybe that is effecting the ejection pattern.

You could also take a look at a BRT EZTUNE gas tube.  All it’ll require is swapping out the gas tube.

I've seen those and they look pretty neat. I'd probably want to call them up in order to explain exactly what I was looking for rather than just using the drop down order menu on their website. For now I'm going to start with the YHM suppressor gas block (I already ordered one from PSA for $16). It's much cheaper than the BRT gas tube and gives me some ability to adjust it with a drill bit. If the BRT isn't ordered right the first time, I'd have to order it again which could get expensive fast. This is meant to be a budget build, so I'm trying not to let my ocd drive the cost up.

Just wanted to follow up on this with a little update. I bought the YHM suppressed gas block and before ever shooting it drilled it out to .09375". I figured this would be a little under gassed but I wanted to start there instead of drilling out too much and having no way back (without buying another gas block). As expected, it was under gassed. It cycled supers with or without the suppressor just fine, but would not cycle subs either way. So I went back and drilled out the gas block to .1015". Now it does not have enough gas to run subs unsuppressed at all, which is fine. And it doesn't have enough gas to run subs reliably with a suppressor, but it's close. I was able to get it to cycle about 9 out of 10 times and even lock back on last round, albeit a weak lock back (it would catch on the carrier, not the bolt). At this point I figured I would take it home and drill it out slightly bigger, but I still wanted to test supers. Supers unsuppressed worked fine, no issues at all. Now here's the weird part though, it appears to be excessively over gassed on supers suppressed just as bad as before I added the restrictive gas block. about 1 out of 10 cycle too fast to pick up the next round. Somehow I have a narrower range of operation than I did before.

I have an A5 buffer system on the way with an H0 buffer. I'm thinking this might help with the excessive cycle speed since it has a little more travel length. I'm going to leave the gas block as is until I install the A5 and give it a test. I may just go back to the factory gas block at that point, but we'll see. I know an adjustable gas block would make this whole process simpler, but I really don't want one on this build. I just want a reasonable range of operation without having to adjust anything.

PS, I also tested the gun on a standard lower with no Law folder and it performed exactly the same. It seems like the extension plug doesn't make much of a difference, despite the fact that it adds almost 2 ounces to the bcg/buffer.