I'm not sure WHAT book you bought but in my experience reloading shortened 10ga hulls there is no difference in hull life between the 10 and 12ga shells. Maybe the regular length shells are hotter and the ends go bad. In the Alliant handbook there's some loads for 3 1/2" 10ga that are in the 8 to 9000psi range. I wouldn't think they'd be so hot as to ruin the ends too quickly. I have a Parker, Lefever, and Remington SxSs in 10ga. I just use them for fun shooting at SCs, so loads are light - 1oz. I don't shoot them a lot, but the shells seem to holding up just fine. Because I load at lower pressures - 7 to 9000psi - I don't mind subing in different components IF I think it won't make a difference. With that said, I've found all 10ga shells are straight walled, so I feel they can be interchanged. Looking in my Alliant handbook the Win, Rem, and Fed shells all have close to the same pressures with the same components no matter what hull is used. Cheddites are just a cheap foreign straight walled shell. I found the biggest problem is the shell wall thickness seems to be a bit thinner than other gauge shells. They will wrinkle a lot easier in the plastic wad cushion area if the total load stack height isn't right. The Federal hulls also do it. If you're just gonna use up some old fiber wads trim the hulls down to a shorter length so less wads are needed. I had a Parker lifter 10ga that had stepped chambers at 2 5/8. So I cut all my hulls to 2 5/8 to make life easier. They work just fine in the longer chambers and use less material when reloading. You could cut a couple down and see how they do. I know 10ga empty hulls are expensive. I use to order 50 Rem hulls from BPI or Precision Reloading. Then a friend who hung around a local DNR range would pick up empty 10ga hulls and give them to me - Fed, Rem, and Win. I'd treat them all the same - just use some mild 12ga data, sub in the 10ga wads [ if plastic, Rem SP-10, then use a 16ga fiber wad in the plastic wad for filler ] and load and shoot. If you're going to shoot heaver loads the Alliant handbook has 1 1/4oz loads using Green Dot, and Unique. The Blue Dot loads are for 1 7/8oz of shot. Hope this helped.
