8mms brand cases I am messing with range from 160 grains to 188 grains
I tested WW2 30-06 brass extensively and the stuff nearly had the weight spread of your 8mm brass. My test groups got rounder and smaller when I weight sorted the 30-06 and divided it up by weight.
However, I was shooting the stuff in a Wilson match barrel.
In my 223 match rifles, I regularly shoot mixed brass out to 300 yards and I shot HM scores sitting and rapid fire prone. I have never seen 223 brass with as high a weight variation as your 8mm brass.
I have 3 different brands of 8mm Mauser Brass, S&B, PPU, And Winchester. Would it make much of a difference in accuracy if I loaded the same load in these cases in my M24/47?
Here is the thing, unless you have changed the barrel, removed all the military hardware and bedded the thing in a good aftermarket stock, your rifle is a military rifle. It is not a target rifle, the barrel is not that high of quality. I have several of these Yugo rebuilds and the Communists were not into quality control. Nor were they into building precision rifles, these things were assembled to go bang. So, I really doubt you are going to see much of any accuracy issues with mixed cases.
If you are going to keep it in full military condition, bed the action in the military stock, adjust the trigger for a clean release, and install a new mainspring. Then, and only then, go play around with different bullets and cases.