The other day i pulled out the percussion for the first time in about 5 years, when i try to put on a no. 11 cap they wont seat fully, these are the same cap-nipple combination i used to use all the time. i have tried a new nipple, and a different tin of caps, no im not using a musket cap nipple and everything is squeeky clean. i even took the old nipple to the shop and polished it up but still the same.What happened with age? i will try some winchester caps as these were CCI but ive never had a problem with them before. ????? Thanks