pricedo wrote:How many lube grooves does the bullet have now? ........... & it's a safe assumption that you're using gas checks?
There are three grooves on the "330" and four on the "350". It is more than just "how many" as far as lube grooves and their volume goes. It takes a detail analysis of the lube area and volume against a number of factors, more on this in a bit.
Yes, the mold is gas checked. I don't shoot plain base bullets from my rifle as I am looking for jacket bullet performance.
If you're not getting any gas leakage, lead fouling or other indications that another lube groove is needed .........why bother?
The answer is yes, there is fouling above 48.0 KPSI but the answer is not that simple as the pressures this cartridge operates takes special considerations. A tougher bullets is needed to explorer the performance offered. BHN isn't everything either, different alloys at the same BHN respond to pressures applied to them differently. All this must be worked through to get this cartridge up near its max but that is what makes it fun.
A 330 grain cast bullet is about optimum for the 454 Casull in a 92.
Yes, I agree based on terminal projections of bullets from 280-grain through 360-grains. 330 is optimum of any performance criteria.
How fast are you moving those 330 grain bullets past the muzzle?
I believe that they will be pushed out the barrel at 2000 FPS for approximately 2925 FPE. This should make it quite a pumpkin to chuck!
Maybe the case capacity would better be used to add more powder/velocity rather than a redundant lube groove?
If it ain't broke...
Exactly, heavier bullets start to rob the case of powder capacity as the OAL is fixed so the additional length of the bullet (the result of the weight increase) must be pushed somewhere.[hr][/hr]
When comparing the bullets I've designed of a like volume (cc) this bullet is at the average of any of number of factors effecting it's lube performance. This would include ratios of Bullet cc to Groove CC, Bullet CC to Lube Weight (grains), Bearing Length to Groove CC, and Bearing Length to Lube Weight. When compared to an index of bullets with a cc volume of 1.900 through 2.100, the TLC452-330-RF sits at a tenth above the average so it is good to go. The group of bullets in this comparison include some of my most successful designs such as my 444 Marlin and 45-70 Govt bullets. I have no doubt this morning that the 330-grain bullet will be a winner.
So that said, I've got to get the drawing to Lee. I'm also casting alloys this morning to testing at the higher pressures needed with the cartridge. More on that later.
I've quietly gone through all of this with every one of the 39+ bullets I've designed. Bring a design up to completion can be costly and getting it wrong even more so. It is something I enjoy doing.