ain't never needed the taper crimp yet, in all those years & when I was on the door kick squad, we shot 300 rds a week thru our sidearms alone..........on the tumblers........ Maury said to try the new stainless steel pin media instead of corncob or walnut hulls, with water, a lil Dawn detergent & said that all his brass comes out super clean , including primer pockets in 1 hour or so, MidwayUSA's site supports this in the old style Thumblers tumbler......... the media is re-washable & lasts forever with no damage to the brass.