bullet for 18"twist 40 cal

Thanks for that Ed .   I should have been more specific about my question as well as my goal.  My goal is to find the longest 40 caliber bullet that will stabilize  in the 18" twist of my barrel. I bought this rifle used and would prefer it had a 16" twist but it is what it is so I want to make the most of it for long range shooting which is normally out to 800 yards but occasionally farther. What I was hoping to find is a Postell type design at not over 1.25" and at close to 370 grain.

I have an old NEI mold for a bullet of that type but it is too long at 430 grain in the BHN-9 alloy I use. I am now wondering if there is a service that could convert this mold to a nose pour adjustable weight design.  If I could reduce the weight of this bullet to the target 370 grain the length should also be very close to the target 1.25"

That would be one possibility among others.  I have also started a search for the original Lyman mold for a 408" 370 grain round nose but that may be a rare gem.  I do have the vintage Ideal mold that was intended I believe for the 405 WCF which is a 300 grain round nose plain base .  It drops at about .412" but by nose first sizing can be sized down to a concentric .408"  I just wanted something with a little more weight that stays within the max 1.25" length to get the highest BC within my limits.