good to hear!
I dont what it is about mag length and the Lott -- maybe if you load rounds with the bullet out that little bit more or different styles of bullets you would be fine.

as to the roughness - I would take a little polish paste and put it along the bolt shaft - keep it out of the lug area and the bbl etc, and work it back and forth while watching tv - I used to do that as a young man with grease and polishing paste on all my rifles - to just take the edge off of some of the high spots

The one other thing that I saw on my .416 550 was that the edges of the feed lip are scraper knife sharp and I just touched them up a very slight bit with very very fine emery cloth to lessen the scoring of brass as they come through the mag well. It happens with age as well - but I just speed it up a bit

be very careful with any kind of polish or metal removal tho --- you cant put it back

keep working with that rifle and soon you will know if it will do anything wonky

also - maybe try it with .458 win mag rounds to see if it acts different as you may need to use them in a pinch in Africa or somewhere

check to see if any cracking is starting in the stock. Again, I relieve 1/8 inch right behind the tang just to stop the slam of that tang that acts as a wedge.

now the 505 ......... please keep me advised as to how this one comes out as I am looking at one ...

good luck