Kroil
I went to the match in Palm Bay FL on 9 April, 2005; where I leaded the barrels on my Martini 30/30 bench gun and Maynard Model 16 in 32/35. At Burger King, while drowning my sorrows in a biggie-sized meal, I tried to figure out why my guns were leading. I have a set of rifles that work well without leading-or did. Along with the two mentioned above, there’s a M54 Winchester in 30/30 and a C. Sharps Model 1875 45/70 that have been very reliable until lately. Leading is caused by bullets that are too small; I believed this and tested this theorem for many years. The bullets for these rifles were of the correct sizes; something else had gone wrong. 
Munching my way along, I had just about decided that the alloy was at fault. Wheelweights, but I’ve been using wheelweights forever.   
Then, while stuffing fries in my pie hole, I thought about the Kroil. I’d seen Kroil advertised in old gun magazines, but never seen Kroil itself until recently. I bought a can about a year ago and liked it. It cleaned well, and later I found that a tight Kroiled patch, tight enough to squeak when it was pushed through the barrel, would remove lead slivers. I have been using this method to remove lead for months, and wondering why the lead? Cleaning every 2-3 sighters and 10 record shots was mandatory.
Sucking up my diet Pepsi (I do care what I look like) I thought that perhaps the Kroil was at fault.
At home I cleaned these four rifles with Marvel Mystery Oil-what I used to use for cleaning-and patched a little lithium grease into the barrels. 
Wednesday, April 13, 2005, I shot each rifle over 25 rounds each and then cleaned. There was no lead in any barrel. The 30/30’s, with bullets lubricated with NRA Alox lube, took the normal 8-10 patches to get a clean patch. The Sharps and Maynard showed clean patches after four-Darr lube has always worked like this in the past. Groups were fine in the strong wind, with a 45/70 group at 1.3”, some 30/30 groups under 1”, and 27 shots through the Maynard in 3.45” wide X 2.5” high. 
I’m convinced that it’s the Kroil, that the Kroil cleans the barrel TOO clean, causing the barrel to lead. Following the Kroil with Marvel Mystery Oil and lithium grease may solve the problem, but I’m back to MMO for all lead load cleaning and the Kroil’s going on the shelf.
Joe b.

I too fall in the category of "Kroil virgins."  I have a bottle of it but that bottle has never been opened.

On the other hand, I DO have rather strong opinions on too-clean barrels based on the dreaded "wild first shot" syndrome.  What I have begun to do is follow the rimfire shooter's dodge of running a couple of clean, dry patches through the bore to wipe out the fouling...if there are no fines of lead, I just leave it...if I am starting to get leading, then I will clean it thoroughly while assuming I need to break it in again before I fire another shot for record.  It works on my bench gun with a Douglas bbl using 25-1 alloy and the infamous Frog Guano lube, so that is the most rigorous testing I can do.   8)

Froggie

I too have used Kroil, and although I use it straight for lubrication of moving parts, I cut it with Hoppes #9 for cleaning and oiling the bore. It has worked well for me in a 50-50 mixture for bores.

Now listen everyone! What do u want your barrel prep with? Now thank about it a minute! OK give up? BULLET LUBE U ARE USING ON YOUR BULLETS! Yes thats right with your bullet lube it has everything in it to protect your barrel form rust and more! You will find your first shoot out of the barrel will come very close to point of aim! For sure if u blow some graphit down the bore!