In my use of longer hulls in short chambers if the load is same pressure as the gun was meant to use I haven't seen the hull feathering you show. Some of the guns I have used these loads in include an English Hepplestone, a French Ideal, a between the wars Sauer with 65mm chambers and a 20 ga LC Smith with original 2 1/2" chamber. I'm not saying it doesn't happen just that if the load is correct for what the gun was originally made for I haven't seen it happen with longer plastic hulls. ymmv