Ideal/Lyman 225415

Ever since I bought my first Lyman S.C. 225415..the lighter 48-49gr. original version in 1972 I have been intrigued by this little bullet.  Over the years I have accumulated 1/2 dozen of these S.C. moulds...However, nearly all have the same problem..casting undersized and egg shaped.  The dia.'s are usually .225 on one side,but rotating bullet reveals dia.'s from .223-.224” on the three driving bands.  I have hand lapped some to bring as cast dia. up to .225” to .226” all around..but lube grooves are probably still uneven.  I even spent some serious money on Corbin reloading-press type sizing dies to bump to a uniform .226” dia.  This last effort really paid off in accuracy as the gas-check is swaged flat and absolutely square to bullet base.  In the past few weeks I purchased a couple of Ideals...One at first glance appears to be an early unvented block type..but looking closer the block faces appear to have been face-milled at high surface feed rate leaving distinctive machining marks across their surface.  The mould was advertised as an early vent Ideal, and I believe it is just that..I have never seen another Ideal in any caliber with such venting.    The sprue cutter has the circular shaped cutout for the stop pin..preventing mould from opening until plate is swung open.  Now here is where thing get  interesting.  Using an alloy of Steriotype diluted with pure lead..about like the original Lyman #2...bullets drop from mould with a base band of .227", middle band .226” and top band of .225” dia.  Bullets are very nearly perfectly round.   The other Ideal is a later one with the std. straight vent lines and the straight surface that bears against the plate stop pin.  This one is stamped  U225415..and I was sure it would be another undersized disappointment.  This one however, drops with all three bands a few tenths of a thou. over .225” dia. and is also very near perfectly round.  This one had another hidden surprise..Every Ideal/Lyman 225415 mould I ever had or seen has always had shallow radiused lube grooves.  This one has deep flat bottomed grooves with a 60deg. angle to their sides..like a V belt pully..it is in fact quite modern looking.  Wonder why Lyman never adopted this style?  So finally after all these years of searching for a proper dimensioned 225415 I now have two.  These little variations in Ideal/Lyman mould manufacturing sure are interesting! Now to see how well they shoot!