As said, check the vent liner to make sure its clear. I always fire just a primer through my gun before I load it to go hunting (I'm sure my neighbors love hearing that snap out the back door at 4am) to make sure its clear. I also don't leave mine loaded for an extended period of time. I'll load up for a weekend hunt and if I don't shoot a deer during the couple days, ill discharge it in the field and reload the following weekend. The longest I've gone this year with the same charge in the gun was 4 days over thanksgiving weekend.