As most of you know, the muzzle crown has a big effect of accuracy.
With the Mini, you must clean the barrel from the muzzel end.
Take a good look at the muzzle on you mini. Any damage will hurt accuracy. Not to mention that factory crowns are not always the best.
If you are looking for the best accuracy, I suggest you have a good gunsmith re cut the muzzle.
Depending on how much damage has been done to the muzzle from cleaning rods, nicking it etc, you can and will see better groups.
There is only one correct way to clean a barrel on any weapon that does not have cleaning rod access from the breach end. It is to put the rod through the muzzle, attach the brush or jag to the end of the rod at the breach end and then pull the brush from the breach end to the muzzle end.
Do not push the brush in from the muzzle end or scrub the barrel or you will damage it.
Just one improper cleaning can hurt the accuracy of a barrel. When you push a brush into the barrel from the muzzle end, you are pushing metal and dirt into the metal voids in the barrel.
Just picture the bullet as it goes down the barrel. It pushes any small metal rough spots towards the muzzle. When you push the brush from the muzzle, you are putting the jacket metal and dirt under the metal that is pointed towards the muzzle by the action of the bullet. It may seem like a minor thing, but it really does make a difference.
To protect the rifling and muzzle, I took the plastic end from a Dillon priming tube and lightly filed around it until it fit into the muzzle. I put the plastic piece into the muzzle and then put a coated cleaning rod through the barrel to the breach end where I attach the brush or jag.
I then hold the plastic piece into the muzzle as the rod goes in, and when it is pulled out and let the brush pull the plastic piece out when the brush exits the barrel.
The plastic piece keeps the rod from rubbing on the rifling and protects against nicking the crown.
The brush or jag is then taken off the rod, the rod pushed back through the barrel to the breach end and the brush or jag are re attached at the breach end and the process starts over again.
This protects the muzzle from damage. Also wipe the rod every time it come out of the barrel before putting in back in.
Yes, it takes more time to do it correctly, but it is worth it.
There are commercial muzzle protectors available, but mine cost me nothing as I had a bunch of priming tube ends.
Another subject is bore cleaners. The one's with a lot of amonia will etch a barrel if left in too long. Best to use a cleaner without Amonia if possible, but sometimes it's the only thing that will get copper fouling out.
Hoppes # 9 has less amonia than a lot of others.
Amonia is deadly to stainless steel barrels, really etches them, so be extra careful with a S/S barrel.
I sometimes think it's best to really clean well with a bore cleaner without amonia, the use some JB Bore shine to get the copper fouling out, just go easy with the bore shine, it has a very, very fine abrasive in it, about the finest of any bore cleaner, good stuff.
The other method I really like and have been using lately is the Otis or Remington system with the plastic covered flexable pull wire.
It's really easy to attach the jag or brush in the breach area and the cable can be guided out of the muzzle, not letting it hit the muzzle using your fingers to guide it. It's a great bore cleaning system and easily goes to the range with you, no cleaning rods needed.