Elric
Well-Known Member
Aw, shucks, Ma'am, it ain't nothin'... 
Handloader’s Manual by Earl Naramore
Small Arms Technical Publishing Company, Plantersville, South Carolina, Sept 1937
Page 189-190
The fit of the dowel pins on one block into the holes in the other block governs the alignment of the two halves of the cavity. When used properly there is very little wear on the holes or the pins but if the mould is yanked open and slammed shut, the holes will become burred at the edges and enlarged, which will throw the two halves of the block out of alignment and make it impossible to get perfect bullets from the mould. This looseness in the two halves of the block is known as “shuck” and can usually only be eliminated by returning the mould to the factory, having the holes reamed out larger and new dowel pins fitted.
Page 202
Unfortunately, the improper use of a mould not only results in setting up burrs around the dowel pin holes but it enlarges the holes, causing a condition known as “shuck”, or an angular alignment of the halves of the block. There is no remedy for shuck except to return the mould to the factory. The pins must be removed, all the holes lined up and reamed out larger, and new and larger dowels fitted and this is no job for a novice without special equipment
Handloader’s Manual by Earl Naramore
Small Arms Technical Publishing Company, Plantersville, South Carolina, Sept 1937
Page 189-190
The fit of the dowel pins on one block into the holes in the other block governs the alignment of the two halves of the cavity. When used properly there is very little wear on the holes or the pins but if the mould is yanked open and slammed shut, the holes will become burred at the edges and enlarged, which will throw the two halves of the block out of alignment and make it impossible to get perfect bullets from the mould. This looseness in the two halves of the block is known as “shuck” and can usually only be eliminated by returning the mould to the factory, having the holes reamed out larger and new dowel pins fitted.
Page 202
Unfortunately, the improper use of a mould not only results in setting up burrs around the dowel pin holes but it enlarges the holes, causing a condition known as “shuck”, or an angular alignment of the halves of the block. There is no remedy for shuck except to return the mould to the factory. The pins must be removed, all the holes lined up and reamed out larger, and new and larger dowels fitted and this is no job for a novice without special equipment