I came to a conclusion which I think has some logic. This is merely a recounting of an observation/deduction.
I do not expect micro groups from my semis compared with same cal in bolt - and one reason I think is the possibility - probability even, of bullet tip distortion, even if very slight.
What really brought this to mind was re a problem I used to have with my L1A1 - a Century ''less than perfect'' rifle! I did some work on the feed chamfer (I set up gas valve too BTW) and smoothed things up and now functionally it runs well but - think of the round stripping off mag - first from left - then from right and so on - it feeds by bullet sliding past chamber chamfer on one or other side.
This will apply to most semi's with double stacking. My FAL, Mini-14, AK, SKS etc ... I assume same too with AR family.
I noticed with L1 that even when a round had fed to full chambering, if I removed it and inspected the bullet, there was a visible slight marring of the nose - not much but IMO enough to affect absolute axial symmetry - and so flight stability potential.
Furthermore, inspection of the chamber mouth chamfer often shows a slight copper color as feed rubs bullet nose against this area - both left and right.
Most bolt feeds strip off a single stack mag but also - feed round in a more linear fashion and probably less aggressively too.
So - IMO comparison might be with, say, .308 - a 1/2 MOA performance from a good bolt, as against MOA plus from the semi.
Obviously barrel lengths and action effects also come into play but it strikes me this bullet distortion potential is a significant reason for many semi's never being able to outclass a bolt action.
There ya go - just P95 musings - again