Let me give a few pointers I have found out over the years. Some by being told. Some by beating my head against the wall. The odd one you may not like, that does not negate it’s truth or importance. If You have questions fire away but for now I’ll list a few things which for the most part address what You are into at present.
- When we think of accuracy we tend to think of small to medium being accurate with large being acceptable at best. Opposite with cast (Contact area). We have a saying among those I shoot with. If You wanted someone to catch onto cast bang on first time what would You do? I’d hand him a Marlin in 45/70 and a wnfp GC mold exactly .458 with a good strong ogive. Virtually any person that draws a breath could get good groups out of that. With large diameters perfection in casting/sizing is less critical because obturation will pretty much solve any sealing issues. As much as I don’t care for lee products that is why their heavy 45 cal stuff is all 457,,,,,,,Obturation
- Something I didn’t point out to You before because I just caught myself doing it while I was out casting/sizing today. I mentioned sizing front wards instead of backwards. We’ll talk on that later. There is a key bigger than that. Try to aquire molds that drop as close to the size of Your throat as possible. When I run them through to put checks on I just want to barely see witness marks where the die touched but really didn’t remove, more like just polished.
- Actual removal of metal post casting is a great way to shift the mass of the BULLET off it’s center axis. Even as little as 1-2 ten thousands of an inch is detrimental. If You combine that with doing it backwards and God only knows where you are.
- So to go back to one of Your questions. Your bore don’t matter. It’s Your throat You want things sized to. Above 375 cal You can have a thou clearance in throat. Personally in the 30 cal range I would want as close as possible.
- Remember another thing to. That small cal will not exactly have a slow “Made for cast” twist IOW those bullets will want to be water dropped
- Lastly. Cast can NOT suffer a jump to the lands unless You’re just talking a couple thou.
- If You go to the Mountain molds sight Dan used to have a place You could click and it would show a diagram of how things should look in a chamber loaded with a cast bullet. The visual helps
Anything more drop me a note
