As eldequello said, if you're shooting Triple Se7en pellets you are probably experiencing a hard crud build up and you need to swab that out. If the spit patches do not work, use a bore brush on the end of your ramrod. Wrap a patch around that an put some bore cleaner on that patch then push that down there and scrub the crud ring off.

Some things you could do to avoid that is change powders or primers. A cooler primer will sometimes cause less of a crud buildup to occur. Switching to pyrodex will still have fowling but it is usually much easier to remove. Then there is Pinnacle, APP, and Black Mag3 which produce little or no fowling (I've never had a chance to test Black Mag3 but the people who recommend it I respect highly).

I think your deer got lucky on a mis loadeded rifle. Be careful with crud rings. You can sometimes short load the rifle because the crud ring will give you a false sense of hitting the powder charge when you actually have not. If it were bad enough you have a barrel obstruction.

Good luck in the future.