PNE - some guys have descent luck with plastic in their smoothbores, while others get plastic welded onto the interior, even with a couple hard cards between the plastic and the powder. Black powder burns hot enough to melt the plastic, which is then sprayed onto the bore - not a fun job to clean out. It's best to stay with normal wadding - and some experimentation will show what combinations to use. In most guns, varying the powder charge and shot column height and weight can get things in order. Some guys use only.y the thin "B" wads over the powder, several to get a seal, while others use the considerably more expensive 'woven' wads - yours to experiment with.
A slight jug-choke can help patterns and not disturb RB shooting as well. A mere .005" of jugging can help considerably, as it slows the wads and helps prevent them from punching into the shot column. The use of light wads seems to allow the wads to spin off away from the shot column at the muzzle and give similar results. I've never had a problem getting normal wad columns to shoot well from cylinder bores, buy am open to trying some of the other methods. It's all about experimentation and patterning the loads. Large sheets of paper or cardboard should be used as small 'target's won't show the holes that develop in patterns. Holes are what wound or cause misses on game and birds. Even patterns are what you are after. A 30" even pattern at 25 yards is the goal for a cylinder bore and should contain 70% of the shot load at that range. This will give a killing pattern to 30 yards. A slight centre concentration of the shot pattern might add a couple yards to that range. As a rule of thumb, heavy shot loads cause long shot strings (shot cloud very long and sparse at any one point) that give misrepresentation of the effectiveness of the pattern on paper - they look good, but on passing birds, hit with very few pellets - again, as a rule. Square loads, generally give the best killing patterns.
Good luck.
