Yep, with a .490 ball, .010 patches are too thin and will blow to pieces.
Assuming that the grooves are .010 deep, that thin patch will barely get into the bottom of the grooves and won't seal well.
I suggest a .015 patch, to start with, and go from there.
In addition, I suggest that you scrub the factory bore preservative out of the bore with brake cleaner, then oil it well and scrub the bore with a 1 1/2-2" square of green scotch brite pad on a 45 cal jag to remove any offending burrs on that new barrel. Oil the bore well, and scrub about 50 strokes, counting one cycle of in and out as one stroke.
You can use two .010 patches, but it's gonna be harder to load than you might think, not to mention that you will learn to appreciate a "mallet" and short starter rather quickly. Again, I suggest beginning with .015 and try .018" patches as you work up a load.
Either way, you will need to smack that short starter right smartly with your hand to get that patched ball into the bore.
God bless