It is worth a look up the barrel of a Model 17 Remington or a Model 37 Ithaca if you suspect mud or snow blockage. It is a bit more difficult than on other guns, but, if the sun is out, you can see light if you hold the gun up to the light. You can always drop a rock through from the muzzle, if it is a clean rock. Anything is preferable to a blown barrel.