Several things could be going on. If the patches were lubed some time ago, they may have deteriorated. I've had that happen with some lubes. Ballistol has been reported as one that does that on another bp board. After a couple years the force of the short starter can tear them on loading. Had some homemade tallow and beeswax lubed patches that did that. Lube at the range for each shot. Try a couple different lubes, including Crisco and/or straight olive oil before going out and buying something expensive. I have used Wonderlube slathered on the bottom of the patch and could shoot all day without cleaning. You have to experiment to see what works best for your rifle. Your unlubed cloth is probably still good to use. I use bear grease mostly now, but still use Wonderlube on a couple guns. It all depends on the rifle. Mutton tallow with a bit of sweet oil seems to work well, but still needs a bit of proving before I give up the Wonderlube. Lots of things work, just don't leave a greased patch around for more than a few months before using it.
I prefer patching material bought at a fabric store to that that bought at wallyworld. The weave seems tighter to me.
If you have fewer than 200 rounds through the gun, you might be tearing patches on some rough sections of rifling. Shoot more or wrap some 4ought steel wool around a jag, add some oil, and give the barrel 100-200 full length passes to help remove burrs. I have a CVA Mt. Rifle and shoot 70g 3F or 80g 2F and it gives sub-2" 5 shot groups at 50 with my 71yo eyes. Your powder charge is a bit stout from my experience, but each rifle has its favorite load.
If fresh patches and lube continue to tear, you might try some very fine emery cloth and your thumb on the muzzle to remove any fine burrs. Only need to make a few rotations. Again, shooting the gun more will eventually remove these. Let us know if/when you get it to perform as you want. HTH.