well, don't feel bad ... it seems that you have a bad load under the load you put in.
* the advice about ditching the pellets is good ... I would also recommend that you ditch the pellets and get some real black powder ... 3 F will probably be your best bet ...
* you will probably have to do as Zonie recommends - replace the nipple with a zerk fitting and shove out the whole mess with grease. messy but effective ... once done, you will of course have to clean up everything ... have a good bit of something disposable under the muzzle to catch the grease ... i used a brown paper shopping bag when this happened to me & it worked OK ... do this outside .. (don't ask me how i know)
* again, don't feel too embarrassed ... there are three kinds of people who "dryball: those who have, those who have and won't admit it, and those who will soon ...
* it appears from the photos that you have a Thompson Center "Renegade" (if the barrel is one inch across the flats, yours is a Renegade, if it's not, it's most probably a "Hawken." These are well made rifles and, although they don't have much to do with the "Hawken" rifles of the Hawken brothers in St Louis, they will provide you a lifetime of good service if properly cared for.
* if it is in fact a T/C, it most probably has a "patent' breech. this design features a smaller channel between the flash channel and the bore ... make sure that (if your rifle has this feature) you have a smaller brush to clean out this smaller bit ... if not, stuff will clog up in it and you'll have crappy ignition, or no ignition ... the system works great when it works (which it will if kept scrupulously clean) but pretty badly if not...
*DO NOT try to remove the breech plug. if you do, and you manage to get it apart without damaging the whole deal, getting it back together without messing up will be either an incredible stroke of luck or will take more work than you care to put into the system... i did this once - i have the toolage for it, and i was able to get the flats to align, and the faces of the breech and the breechplug to align, but not exactly, so i had to re- file and refinish the whole deal ... doable, but a big pain in the bla bla bla ... don't go there - it's not necessary ...
* once you get the load(s) pulled (actually pushed), and the rifle cleaned up, you will have a perfectly good and serviceable gun, which will give you a great deal of pleasure for many years. do:
DON'T GIVE UP
* also, once you get the mess cleaned up, grab a copy of Dutch Schoultz' method. Here's a link:
Black powder rifle accuracy system -
* hope this helps, and,
make good smoke