Sorry for the long post, but anyone who will actually hunts or wants to hunt ducks with a Pedersoli shotgun will find this very helpful.
I contacted Pedersoli and they were hesitant to recommend steel for a 10 ga with screw in chokes. Their American contact said it would be fine if care was taken using appropriate shot cups, Mylar wraps and load development. Pedersoli will offer no warranty since some nut will use steel without a shotcup (or spilled outside a shotcup, or use shotcups that are only good for lead, or use harder steel BB’s from Wal-Mart for BB guns, use paper for a shotcup for hevi shot) and score the barrel and come back after them. There are posts with each of these examples on the web plus one guy who took a duck on the wing! I believe Pedersoli has the appropriate policy.
Steel Load recommendations 10 gauge Pedersoli with screw in Mod and Improved Cylinder Chokes.:
3 3/4 dram Allient sub powder (a lot less fouling than Goex so less blow by and no melting of wads) - thick green wad Precision Products in 12 ga 3 1/2 fits down my 10 gauge without a titanic struggles (these wads had the highest melting point) tried three wad types from Ballistic Products, Turkey Ranger Plus was the best but only 1 1/4 oz steel capacity. TPS and MM wads worked once I was using enough wadding, all need a Mylar wrap so no shot can escape the shotcup and enough wadding to prevent any blow by that melts wads) - 1 ½ oz number 1 steel kills ducks dead to 40 yards +. IXT is nice for faster reloading early in morning just using a couple over shot cards over the shot for wadding. For steel use two/three overshot cards (or a nitro card, but for hunting keep overshot cards in one front pocket and thick fiber wads in the other) and 1 + 1/2 thick fiber wads with some lube, no melting or blow by or plastic fouling. Tested and patterned steel 3's through T's + duplexes for ducks and geese, +hevi shot, + IXT loads... Adding 1/2 oz # 6 hevi to 1 oz steel made noticeably better hunting loads, but steel alone worked well with the right load.
Best loads for steel used a parachute wad, drill a hole in the bottom of a shot cup, tape up the petals so it can not open (remember I am using a 12 gauge wad in a 10 gauge so this is safe), run a string through the hole in the bottom tie it to a plug, and tie on 1 big cotton ball about four inches down the string to make a "parachute wad" same principal as a “new” federal flight stopper wad. Use at least a steel 1’s or larger on the bottom of the 3 1/2 inch shot column (they leave the shotcup much quicker than smaller shot, physics with s and p wave principal, and if you want a denser pattern duplex with 3's or 2's on top the steel 1's great patterns to fifty yards good to 60 yards (go test this with pure steel 3's leaving the shotcup at forty yards (big downside) you have a sixty yard + load, that said you have a slug at 35 yards). I found I did not need the parachute wads since tend to not take shots that far. Easiest load is IXT and not as expensive as it seems vs. all the time, money effort for developing steel loads. Added a good quality slip on recoil pad is highly recommended. I have had no barrel damage, scratching or wear but used care so steel never touches barrel, all loads had a Mylar wrap inside the shotcup, and used cylinder and mod chokes. Added buffer and seemed to help tighten patterns with larger shot, but became concerned about barrel pressure with buffers, so I have dropped all loads to 3 3/4 drams powder, easier on the shoulder (below max of four drams). Finally wrapped some loads in a paper post it note and that seemed to help tighten patterns esp. with smaller shot, had three patterns slug with this so do not want to use anywhere near other hunters. With a little practice I got the feel of how tight and how much paper will work best.
Ballistic Product wad Ranger Plus with duplex load steel 3's and 2's 1 1/8th oz load good to 35 yards for ducks over decoys and getting 90% shot in 30 in circle at 35 - 40yards, much easier on the shoulder. Heavier loads were significantly better than 3 inch modern loads shot from my Benelli, but loading time assured ducks will fly by while loading esp. adding extra wadding/steps for steel. The loading time was the biggest disadvantage with steel not performance. There was and is so much mis information regarding muzzle loading shotguns on the web (people who never or rarely hunt ducks, people who don't even own a ML shotgun giving advice) I went out and spent the time and money to pattern over a hundred loads of steel plus a lot of lead patterning, steel works fine in a Pedersoli 10 gauge (use larger loads I really like 1 1/2 oz steel 1's for ducks significantly out performs 3 inch steel 3’s and 2’s 1400 and 1550 modern shells, adding some hevi shot for a properly weighted duplexes made this load even better 1/3 to 1/2 oz of hevi weight 4's over BBB’s T’s for geese (not field tested yet) and hevi weight 6's over 1’s and B’s for ducks noticeable better killing range and power, copied hevi Metal loads but stopped adding flax seeds because it really hurt patterns. IXT is great and the costs are not so bad since fewer shots are taken with ML. IMO unless someone hunts ducks a bit (25 - 35 plus ducks a year) just use IXT as a straight substitute for lead (actually patterns tighter) works great and almost no load development, shotcups, Mylar wraps, or buffer is needed. You will save money because you have to test steel loads extensively or buy additional components. Have many pictures but can’t get them posted.
PS. if you do not have shotgun ballistic software this post was very helpful. http://www.duckhuntingchat.com/forum/vi
... 4&t=110030 for steel shot de-acceleration information.
PPS. The above info is for a Pedersoli 10 ga with chrome lined barrels and screw in chokes, my 12 ga Pedersoli is light, fast with thin barrels and no choke tubes, it is not built for steel shot but is great with IXT or lead. Randy W., Brown Bear, Jugchokes and others have shown incredible patience regarding BP Shotguns questions here and on various websites, I wanted to thank them and make it clear that they are not the ones who have been posting mis information.