So I'm looking for information on buffer springs for a few of my AR pistols each were built from a stripped lower and have right now carbine buffer in them.

First I have a 7.5 inch barrel 300blk and the second I have a 10.5 223.

With the 300 BLK I'm running 110 gr and with the 223 I'm going to mostly run for now since heavy 223 is not easy to find and I don't have the time or money to bulk up. I mostly own 55gr and 62gr. I'm wanting to run heavy 75,77 and 80gr.

So wanting to know what buffer and spring would work best? Do I need to change it from what I have please school me I don't know anything about this thanks!

IMO, the standard 3 oz. carbine buffer is too light. I use 6.5 oz. buffers in my 16" carbine. In my 10.5" .223 pistol, I seem to have found a sweet spot for my overgassed pistol with a 6.4 oz buffer and a 4.0 oz BCG weight. At the moment I am not terribly interested in getting a 10 oz. buffer, so I will probably keep it the way it is.
Don't have any experience with the .300 BLK, but I tend to think heavier is better. Heavy enough to produce a pattern to ejected cases at 4:00 but still lock back on the last shot.

I think I ran an H1 in my 300blk, but I probably could have gotten by with a carbine originally.  I know it has a carbine in it now, but it also has a LAW folder which adds mass.

I think I had an H2 in my original 10.5" 5.56.  I can't remember if it still has an H2 or an H1 in it...but the barrel is now 12.5".