AEA S45 shot string and a few questions

I’m looking to start tinkering on my S45 and ran it over a chronograph for the first time today. This is a cheapo Amazon chronograph, so I might be returning it for another eventually. Here’s the first run, from 4400psi to 4100psi shooting 170gr Mr Hollowpoints:
1. 797
2. 797
3. 795
4. 794
5. 790
6. 783
7. 781
8. 773
9. 773
10. 763
11. 762
12. 761

I haven’t had the gun for very long and the only change I’ve done so far was swapping out the front tank to a 1100cc tank, for a total of 1600cc of air. 1100cc front + 500cc rear.

So here’s where I have a few questions for the pros. I’m well aware my tuning options for this gun are limited, my only real goals would be to iron out the descending shot curve as much as possible while keeping a decent # of shots with the huge onboard air capacity I have. I’ve shot ~50 shots or so from the 4500psi max fill to the lowest recommended pressure of 3000psi! I bought this used off of here and when I received it, the gun was cocked. Who knows how long for, but would this have weakened the hammer spring enough to reduce the shot velocity? I always keep it decocked now. Would a stronger spring bump up velocity at the expense of shot count? I have seen a youtube video of a guy who really digs deep into the S45, to great results. If anyone has any tips or has experience or done work on this particular gun I’m all ears. Thanks.
 
There is no way around a descending shot curve on a big bore that is unregulated. Yours is absolutely fine. In fact if you got 12 shots on 300 psi of air that is literally amazing.
The massive air capacity is pretty nice, makes for one hefty gun but it’s honestly not too bad. Would it not be possible to tune for the classic arch/ upside down U curve of an unregulated small bore gun?
 
Not really safely. You would need to over fill the gun to a high enough pressure that when you start shooting the hammer isn’t opening the valve all the way. You could also put a lighter hammer spring but I think that would cut your max energy produced down. For a high power big bore 800 fps to 760 in 12 shots isn’t bad at all.
That makes sense, would the max power shot at the new arch peak be weaker than your max power first shot as-is? I only understand some of the concepts, the only tuning experience if you can really call it that that I have is with bumping up a Notos a few tens of fps. And that’s completely different since it’s regged. The other thing is I’ve seen others shoot the S45 in the 900-800 range with similar slug weights, which is why I suspect the hammer spring might have been weakened from being left cocked. I know no 2 guns will ever shoot the exact same, but could it be anything else?
 
That makes sense, would the max power shot at the new arch peak be weaker than your max power first shot as-is? I only understand some of the concepts, the only tuning experience if you can really call it that that I have is with bumping up a Notos a few tens of fps. And that’s completely different since it’s regged. The other thing is I’ve seen others shoot the S45 in the 900-800 range with similar slug weights, which is why I suspect the hammer spring might have been weakened from being left cocked. I know no 2 guns will ever shoot the exact same, but could it be anything else?
I suspect your energy probably would be lower at the peak. Not sure about the speed as I’m not super familiar with the s45’s power capabilities. Hopefully some others chime in.
 
After a fair bit of looking around I think I found the hammer spring dimensions:
IMG_6429.jpeg

The hammer spring is part #69. 1.7x14.8x146x34. Can anyone make sense of those dimensions?