I'm anticipating your next thread titled, help I've got a brush stuck in the barrel.
I have oak and hickory, I use oak and hickory. I have a oak dowel in my .32cal now, and have been using it almost daily. Weather it’s a factory hickory ram rod or a home made oak dowel, you can get bad ones. As mention earlier, pay attention to the grain. Dowel rods can and will be ok to use. I prefer to build my own and just carve a cleaning jag in the end, works for me!Do not use dowels. Dowels have grain run out. Oak is not as strong as hickory. When it breaks there is a good chance you will spear you hand.
Stick with hickory rods, hopefully split. When you buy hickory ram rod blanks inspect them to be sure they do not have grain runout.