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I was just looking at a group buy for a 9mm boolit mold. It is offered in BB or FB. Is there an advantage of one over the other? I was thinking a bevel base would be the ticket since it is easier to load but I see most are ordering it as a flat base mold.
BB are a little slicker to load, generally. That being said, I have found that flat bases interface better with brass that has been expanded with an M profile expander. Bullets sit straight when topped onto the case before seating. This is because the square heel of the boolit is setting into a squared off case mouth flair. They naturally want to sit straight. All my handgun expanders are M profiles. The BB profiles sort of want to roll more it seems.
I'm not a good enough marksman to know firsthand if one is more accurate than the other. I have both types. Both work.
I have both, but prefer the FB. For me they cast easier, looks better when dropping from the mold, and I have no problems loading them with my Dillon 550.
The flat base sizes with no problems in the "other than Star" lube/sizers (no lube built-up on the base). On the Star both lube & size with no problem. I like the BB as they're easier to seat: I lube/size on a Star.
Here is a link to a recent discussion on this site about that topic.
http://castboolits.gunloads.com/show...-or-bevel-base
Here is a link to search results on this site for that topic.
http://castboolits.gunloads.com/goog...128j2093434j10
I prefer a flat base. My very limited testing showed that my flat base bullet was slightly more accurate than the bevel base that I compared it to. The BB is a pain to size and lube in most sizers other than the Star.
Thanks tazman (he says as he hangs his head in shame), I should have used the search before I posted.Quote:
Originally Posted by tazman
Thanks to all who have posted, I appreciate it.
I still pan lube many of my cast bullets and a bevel base is a real PIA. I started with flat based bullets, mainly because those I chose just came in flat base (my second mold was a 429421) and it just happened most of my following molds are flat base. I did purchase some bevel based 357 bullets, but I was unable to tell any difference in accuracy compared to the same design with a flat base...