For years air rifles were designed around the lead pellet, if that changes then manufactures will do the same with Pb free ammo, new barrels that have a slow or high twist to match velocities and made harder to deal with the hardness of the Pb free pellet. Manufacture will not commit fully until its definite, if say we have new faces in politics and a ban doesn't take place then the manufactures would have wasted invested money, they wont shoot themselves in the foot and push out their customers, they want new blood to the sport, new shooters more money for them, early days yet, only you giving up will close them down and put up prices.
Pb free pellets just like anything new will cost more to start then hopefully drop in price you can be sure of that, as the Chinese will step in and kill European pellet market for being too greedy, they don't want that to happen, I don't see why zinc or monkey metal mazak should be dearer than lead it should be cheaper, much more and as for swaging machining of the new Pb free pellets its just another machine set up just like lead, no different, just different material.. Given more investment and demand the current run of Pb free pellets will either get bigger to match weight of original standard lead designs, so a 21 grain .22 pellet or slug in lead which is heavy for 12 ftlb air rifles now changed to Pb free will be the new standard Eley wasp weight at 14 grains, bigger in volume but lighter in weight ( not sure what the ratio of lead and Pb free lead is). The standard type .22 Eley wasp in lead at 14 grains will be the new light weight Hobby pellet, the Hobby will be extra light etc. May be we will see more slug type or spitzer or boat tailed shapes in future, pellets that will match old airgun barrel twists and velocities which is the key to accuracy especially in the fire arms world, i know i used to reload my own pistol and rifle rounds years ago.
As for pellet hardness by adding something to Pb free lead or using another material to make it softer on the barrel and target, may be a sintered type material will come, rather than expensive tin use monkey metal mazak with incorporated plastic skirt, to match traditional weights to perform in older guns with tradional rifling twists the projectile will have to be a bit larger in length, may giving more stability over a pellet shape or match it. This time in airgun history there is going to be change, we are in a transitional period, that will work out for the best, a lead ban may not happen on a political scale, remember it was all doom and gloom when the shotgun community had to go through the same thing. If we all have to use Pb free in the end and the ammo is not up to standard and expensive then make your feelings known, you can do it now, get the airgun magazines to voice our concerns to the manufacture because each one now will be competing for the best performing brand as i write, if you dont tell them and spread the word their new pellets are crap then they wont know. Do give up and roll over to political zealots, i wont give up lobbing projectiles ether from air rifles archery catapults or throwing stones, they will have to cut my arms of to stop me..