JeffinNZ
08-08-2008, 04:32 AM
Team.
I real hate the "one size fits all" approach to the pour holes in sprue plates by the major manufacturers of moulds. Proportionally the sprue plate pour holes in .22 moulds are enormous when compared to a .30cal mould or worse, a .45cal. Basically the 4mm hole ex factory is 70% the diameter of the final bullet! That equates to a .32cal pouring hole on a .45cal bullet mould which is just not the case and would be considered over sized.
So I made my own sprue plate with holes more suited to the .22 bullets my 225462 casts. I drilled 2mm holes and today ran the mould for test and it worked perfectly and produced the most perfect looking bases to date.
http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/225462.jpg
The plate is aluminium as supplied by a friend in the aeronautics industry. Though not particularly hard metal it has come through unscathed. I applied a liberal amount of soft lead pencil to the underside of the sprue plate and it ran perfectly without binding on the steel mould.
Here are bullet comparisons. Left to right.
New 2mm hole, original 4mm hole, original 4mm hole offset to minimise.
http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/22base2.jpg
The original 4mm holes are 3.7 times greater in area than the new 2mm holes!!!
Of course now I have to shoot and compare. Just my luck after all this work the results will be not better.................[smilie=1::-D
I real hate the "one size fits all" approach to the pour holes in sprue plates by the major manufacturers of moulds. Proportionally the sprue plate pour holes in .22 moulds are enormous when compared to a .30cal mould or worse, a .45cal. Basically the 4mm hole ex factory is 70% the diameter of the final bullet! That equates to a .32cal pouring hole on a .45cal bullet mould which is just not the case and would be considered over sized.
So I made my own sprue plate with holes more suited to the .22 bullets my 225462 casts. I drilled 2mm holes and today ran the mould for test and it worked perfectly and produced the most perfect looking bases to date.
http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/225462.jpg
The plate is aluminium as supplied by a friend in the aeronautics industry. Though not particularly hard metal it has come through unscathed. I applied a liberal amount of soft lead pencil to the underside of the sprue plate and it ran perfectly without binding on the steel mould.
Here are bullet comparisons. Left to right.
New 2mm hole, original 4mm hole, original 4mm hole offset to minimise.
http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/22base2.jpg
The original 4mm holes are 3.7 times greater in area than the new 2mm holes!!!
Of course now I have to shoot and compare. Just my luck after all this work the results will be not better.................[smilie=1::-D