We use jags that allow 2 patches being used. A single patch on a larger jag won't get to the bottom of the deeper grooved guns - not well, at least. Using a soft material for cleaning, like flanelett works well.
Never had difficulty with tight combinations pushing anything down causing problems. I want the patch the push everything down and out the vent as flushing in waterin and out is the only way I clean my guns- with tight fitting patches.