Antique colt 1877 thunderer

Antique colt 1877 thunderer. 41 long colt, 5 inch barrel, 6 shot. Gun is fireable, but when you do you need to remove the cylinder and use a hammer and punch to unload it. I have tried 4 powders and a dozen different loads and always get the same results.

I am a gunsmith and have polished the chambers and it changes nothing. Trigger return spring is also weak.

I bought this 2 weeks ago and saw a video of it being fired, so that being said I thought it should be ok. 

So if someone wants one for an addition to a collection or for a nice piece of history here is your chance. I paid $3000.00 for it and will take a bath. $2250.00 shipped.

I am looking for one that works. I have lots of stuff to trade, custom hunting rifle etc.