If it we’re a 356402 design sizing to .358” would not be an issue, but it’s a straight sided bullet and sizing even .002” just pushes up the length of the bullet. I’m really not in need of a light 38 bullet.
I guess the most frustrating thing is I questioned the size to the maker just after the order was placed, it took a follow up email to get confirmation they even received my concern.
Don't understand your meaning of a straight sided bullet. Almost all bullets are straight sided, except for a few specialty designs. Your picture shows a conventionally lube groove round nose...............not a bullet designed strictly for powder coating. Don't see where sizing is going to increase the length to a degree that is significant.
I've been casting and reloading for 9 mm, since the mid 70's. In fact, it was the second cartridge that I began with..........38/357 was the first. I currently own half dozen firearms, from six different manufactures, chambered for 9 mm............including a carbine. None have ever been slugged, nor have the barrels been throated. Everyone will take a bullet sized at .3585 diameter. My dies are set for a universal fit, depending on bullet style, for all the firearms.............I don't keep separate ammo for each one. I have at least, half a dozen different moulds. Ranging from 120 - 150 grains I don't get any significant leading in any of the barrels. The carbine will get some minimal leading, unless I use a gas checked bullet. Because, the same ammo I use in the pistols, will be 200-300 fps faster out of the carbine. I cast with an approximation of air cooled WW alloy. I never found where rocket science is necessary, to cast and reload 9 mm.
BTW, I use the 120 grain Lyman 9 mm TC bullet, occasionally in my 357 lever action carbine. Mainly as a small game load. I use a RCBS 38/357 taper crimp die, with outstanding results.............. therefore, crimp groves are not necessary.