Will a 45 ACP sizer/de-capper work for 45 Colt?

[varmint243]

I would check that up in my lathe, face it off, and drill it so an RCBS replacement pin fits in with a little Loctite.
Other than that I suggest using a separate decapping die

 

[Green Frog]

Buy an RCBS carbide sizer die and a package of replacement decapping pins. Life will be good forever after. Think "Standard Parts" and "Inventory in Stock"

I have two Lyman die sets and they are two nightmares. Maybe that is why they were the only dies in stock in .25-06 and .45-70 .

My RCBS die set that I used the most was for 32 Revolvers. With both 32 S&W L and 327 Fed Mag I had a constant problem with the decapping pins backing out and being left in the (admittedly tight) flash holes, especially with the FM. No such problem yet with the Lyman Carbide sizing die and its decapper, but I haven't used it that much. The heads on Lyman's classic replaceable decapping pins keep them from backing out. Not much experience with the new one piece stems, but I would either stock a spare or two or retrofit the old style stems. Just my 2¢!

Froggie

 

[Wireman02]

broke pin

I would get a new die set with a replaceable decapping pin and tell Lyman where they could stick there one piece decapper.