I agree with the above folks who suggest making the ramrod a bit thinner. After filing the taper to match the tip Jim supplies with the kit, I typically sand the rod down with 80 grit paper until it slides all the way into position in the hole in the stock with very little resistance. Once I get to that point, I then sand it with 180 and 220 grit to smooth it out. If you are worried about it being too thin, keep in mind it will swell somewhat when you add stain and finish.
You will likely find that most, but not all, of the initial sanding is only needed along the first 1/3 to 2/3 of the length of the ramrod, as the rod will generally pass through the thimbles easily before it will seat all the way down inside the hole in the stock, which tends to be more snug of a fit than the thimbles themselves. I generally don’t worry about a slight bend in the rod because, once sanded to fit, the bend gives it some spring tension that will help hold it in place under recoil and/or, when you are holding the rifle with the muzzle pointed down.
Good luck.
Jay