Hi all. Thanks for the very helpful info. I agree that I should sort the problem out before introducing new variables like molly coating.
I have been back on the range!!!
I have great news! The fouled barrel solved the problem. I shot two rounds through the rifle on Friday.
On Saturday morning, I shot 5 rounds out approximately 1 minute apart. the first two shots were within 1/2" group, making a figure 8 shape, as they overlapped. Unfortunately, I pulled the third shot to the left by 3/4". The forth and fifth were in the first 1/2" group. I waited an hour and just did a pull through with my snake. (No oils/abrasives at all - new snake) , and then shot 5 rounds again. Again, first three shots spot on around the bull. All overlapped. My forth I again pulled left, but 5th spot o again.! I then went hunting some KOLGAANSE (Large Geese) with a a neighbor. We took shots ranging between 100 to 900 yards. My friend shoots a 300 Win Mag. Savage. I had minimal success on the 812 yard shots, but they were only off slightly (3 to 4 Inches left or right) due to my poor wind estimates. We never had a wind meter, and it was quite breezy. At 350 yards, spot on. The various shots were taken long breaks, whilst driving around looking for the geese. So always a cold shot, and I was very happy with the height placement, according to my chart. Height was mostly 100%, but just my windage adjustments that were not the best.
So, it seems my problem was a clean perhaps oily barrel. Now I am very confident that the problem is solved.
Thanks again to all the contributed.