I don't use anything presently Bill. I just clean the barrel frequently and then a good barrel seems to only take two or three shots to settle after cleaning in my experience.
But I have used
Finishline Krytech wax lubricant which we can buy here in cycle shops in OZ. It has been popular for many years. It seems not to pick up dirt like oils will and keeps bike chains lubricated well, but doesn't get the chain filthy in use. A couple or three drops in a sandwich bag, squash the bag to spread the wax, put 50 or so pellets in, close the bag and roll them around by manipulating the bag back and forth is the accepted application system. Take them out into a tin and put in some more etc. Less wax is better than lots. The main difference I saw was that the barrels remained clean longer.
I have used Inox the Aussie lubricant from Auto stores. Comes in a spray can, doesn't attack anything, is food grade around kitchen machinery, won't wash of with water and is cheap. A little sprayed on a lint free cloth and the pellets rolled in the cloth works. Again less is best. You don't want any liquid rolling up in a ring in the bore ahead of a high velocity pellet. I don't know that such would gall an air rifle barrel but can't think of anything good coming from it. Again the only thing I have noticed is that the barrels remain clean longer.
However until I am mixing it with our best in the 25 metre game Bill, I would be loathe to actually recommend any particular products as pellet lubricants.
Perhaps the top shooters here like Todd, Dan and Co might better advise you on pellet lubrication Bill.
My really high powered rifles, 50 fpe .25 and 40 + fpe .22, do need frequent barrel cleaning, especially the first few inches, and the last few inches where the choke is, and these lubricants do prolong serious cleaning intervals in those. ....... Best regards, Harry.