Reloading ?

[Mortblanc]

If barrel length was the issue then no lead pistol bullet would ever stabilize. The lead bullet engages the rifling in the throat and if the bullet strips it will not "recover" as it goes down a long barrel. It has been reduced to a sub-caliber projectile at the point of stripping.

I cast for both rifle and pistol and black powder muzzle loaders in every mid-range caliber, bullet weight, barrel length and at about every velocity between 500fps and 2000fps.

I cast for 30 caliber in weights ranging from 90 grains up to 200 grains. 30-30/30-06/.308/.303/7.62x54 are all included with charges and bullet weights suitable for game from rabbits and squirrels to deer, American elk and large cattle if necessary.

Some of those calibers do better with heavy bullets than light, with only the 30-30 and 30-06 doing well with all bullet weights in my particular rifles. I have a couple of bullet molds that cast a bullet that rivals jacketed bullet accuracy at 100 yards.

I have found that the depth of rifling is the greatest influence. Our modern rifles usually have rifling only .003-.005 depth, which is fine for jacketed bullets but not ideal for cast lead. I avoid certain brands of firearms due to their shallow grove rifling. If you look back at the target rifles of the 1800s, when all they had was lead or lead with paper patch, you will find deep rifling and extremely long heavy bullets dominated the target ranges with the Whitworth rifle eliminating stripping problems by using a hexagonal bore/bullet with no rifling as we know it.

The longer bullet gives a longer surface area for the rifling to grasp, so the deep grove barrels give some extremely good results with heavy cast lead bullets if the twist is not greater than 1/12.

One of the features of using cast bullets is the uniform top velocity of around 2000fps which is a restriction of the properties of lead. Since one is restricted in velocity, bullet weight/alloy hardness is the only way left to improve bullet performance. When using a 30 caliber cast bullet one will achieve the same ballistic performance from a 30-30 that one can achieve from a .300 Winchester magnum due to the limitations of the projectile.

I can get a shallow grove fast twist barrel to shoot, but only at very low velocities. Fortunately, most light/short bullets will stabilize in whatever one has at very low velocities, and those loads are usually intended for small game at close range. A 90 grain 30 caliber bullet at 500-600fps is completely adequate for bunnies and such within its 25-50 yard limits.

If one desires an in depth study of these properties the Lyman Company has done extensive research over the past 150 years and have most of their findings in print, specifically in the Lyman Cast Bullet Handbook, in which the first 200 pages are reference material and the last section load data.