I have thirty +, .30 cal. molds right now. Since my molds are made by Cramer, SAECO, RCBS, Lee, Lyman/ IDEAL, NOE, Accurate and others , the variations in drive band diameters , gas shank diameters, and nose diameters are " all over the place ".
Nose diameters of the molds described above vary from .299" - .304".
I have .30 cal. rifles that if you try to chamber a round with a .304" dia. nose, you won't ever get the bolt closed. In a hunting situation or self defense situation , If you did get the bolt closed , you could stick the bullet in the bore,, when you withdraw the case from the chamber, powder will fill the chamber and magazine box....a real mess. Basically rendering the weapon useless until you can get a cleaning rod to tap out the stuck bullet , disassemble the rifle , clean the magazine box and get everything back together. If you've loaded very many cast rifle bullets, you have probably already experienced what I describe above. If the nose is sized properly and you have the correct OAL for your loaded rounds, this will never happen. The beauty of a properly sized nose on your rifle bullets is IMPT ! for proper chambering and also an aid in the accuracy dept.
My .30 cal. rifles each like a different bullet dia. on the drive bands. However some of them have tight bores and won't tolerate a " fat nosed bullet." If the nose of the bullet gets much over .3015" there will be problems in chambering the round. I have a Springfield 1903 Sporter in .308 Win. that isn't very tolerant of cast bullets with a nose of over .301". I hope you are able to see why I ( and possibly you ) need the ability to control nose diameters.
I now have the ability to size a nose to .298", .300 ", .301 ", or .302".
I've always read about sizing the nose of a cast bullet, but considering the fact that RCBS, Lyman, etc . didn't sell the nose sizing dies , I just never got serious about the concept.
Several years ago, I had Buckshot make a .302 nose sizing die for me. It was solid steel that fit the Lyman 450 with the threaded ring that holds the sizer die in place. It has been useful, however I found that I
also needed a .300" and a .301" diameter nose sizing die.
I asked Rick Tunnel ( Buckshot ) about making me a cast bullet nose sizing die that would take the Redding bushings . Rick agreed to make the die, the die works flawlessly. This die takes the Redding sizing bushings that are available from MidWay, Graf's , etc.
Here are the bushings, I chose to buy the heat treated, hardened steel bushings since they are about 60% of the price of the Nitride ones. A thin film of lube on about every 3rd bullet going into the sizer ring is all this is needed with these steel bushings. They are polished " mirror smooth".
These 1st photos are of my 1st die that Buckshot made for me, the die body is solid with no lube holes and sizes to a perfectly round .302" diameter.
Here is the die body that Buckshot made me to hold the Redding busings :