I've been doing some digging on .257 bullet molds and figured we could compile some information here in this thread.
Since my platform is the AF Condor I've been doing a lot of reading on Doug Noble's work as well as Cedric's. Doug is the creator of the dyotat AF valve and produces some very impressive numbers and accuracy with his guns. Cedric has a youtube channel where you can see what some of the AF platform is capable of with one of Doug's valves and some other customization:
https://www.youtube.com/user/tofazfou
Some light reading can be found here:
http://talonairgun.com/forum/viewtopic.php?t=26906
I currently have the 85gr 257388 on order from:
http://arsenalmolds.com/products
Very fast turnaround and priced well IMO.
Good sizers and addtional molds can be found here:
http://noebulletmolds.com/
Dave sent me a great general sizing and shape guide located here:
http://ps-2.kev009.com/ohlandl/Cast_...r_257_Diameter
The current common .257 equation involves a .257 TJ liner in 1-14 twist. In varying lengths these barrels seem to perform well up to about 100gr according to what I've read. This will have to be tested once I have a .257 platform here.