I'm running some tests on a 720 grain LFNGC .458 cast bullet. It's designed for the .458 Win Mag and Lott. I asked for volunters from a forum to asisst with load development and testing.Here is the initial load development. These loads are NOT for reloading at this point. They are only safe in the test rifle and may not be safe in other firearms.

"Today I fired three each of the three loads I wanted to try. Below, I report the raw data, the averages, and the extrapolated muzzle velocities. Speeds were recorded at 15 feet. The MV estimates were done with the Sierra Bullets “Infinity†ballistics program using the Hornady 500 gr RN bullet as a surrogate. The recorded speeds are remarkably consistent.

IMR-3031 51.0 gr
Shot 1 1676
Shot 2 1657
Shot 3 1661
Avg 1665
MV 1680

H4198
Shot 1 1754 51.0 gr
Shot 2 1741
Shot 3 1759
Avg 1751
MV 1765

IMR-4895 51.0 gr
Shot 1 1566
Shot 2 1558
Shot 3 1572
Avg 1565
MV 1580

I have attached a photograph of the heads of the fired cases. They are orientated in rows, top to bottom. As you can see, the primers in the top row (3031) are somewhat flattened, the middle row (4198) are flattened and slightly cratered, and the bottom row (4895) are nicely rounded. Based on this very limited test, I consider 1650 fps MV to be maximum for this bullet in my gun. On my next trial I will decrease the charge of IMR-3031 to 50.0 gr, reduce the charge of H4198 to 48.0 gr, and increase the charge of IMR-4895 to 52.0 gr. I will continue to use Federal Magnum Large Rifle primers. I’ll make a similar report then. It may be a week or two, but I’ll get to it as soon as possible."

Cool bullet.

Where can I get the mould (or at least the dimensions of the bullet)?

A friend of mine is shooting that bullet in a 45-120 custom double. He claims 1850fps across the chrony with decent accuracy.

SS

1875SS,

of course there's other rounds besides the 45-70...I got a 38-90 and a pair of 50-110's

Rich
DRSS

I know, I know, I have a safe full of 45-70's and I always get a hard time from some that I shoot with about it. My standard reply is my signature line. Thinking about a 38-55 or 40-65 lately. I do enjoy the 30-40 Krag.


SS

What I would like to have is a 1292.5 gr bullet for my #1 with a big flat nose to kill rats with at the local dump. I would start out at 2 .7 grs. of Bullseye and work up till the bullet exits the barrel then set up my chrony and work up till I got roughly 499.5 fps. With a 12.5 power scope on it sighted at 12.8 yards Do you guys think it would penetrate a large rat on a solid broadside hit? If not should I add more bullet weight or more velocity?

Me_Plat,

What is your point? Let's try to contribute something useful.

720 grain LFNGC

.458 Lott - 1900 fps (data available)

.458 Win Mag - 1675 fps (data available)

Accuracy 1.5" at 100 yards

Impressive:

If you figure a 10.5lb rifle, 90gr of powder, and the 1900fps; the numbers are...

1. Taylor KO Value is 90
2. Muzzle Energy is 5,773ft/lbs
3. Recoil is 84ft/lbs at 23fps

Not too shabby.

Rich
DRSS
Knowledge not shared is knowledge lost...

Very interesting and thanks for sharing.

How is the accuracy and did you experience any leading in the barrel?

Any loads for the 45-70 with this bullet? Where can I get them?

I think I will just wait until someone brings out a 2000 gr 458 cal bullet. I don't want to fool with a lightweight like this. I figure with 543 fps I will get the 90 TKO. Maybe using a few grains of bulleye.

I don't have data for the 720 grain in the 45-70 yet. I did send some samples off for experimentation. I'll post the results when they are available. I estimate 1300 fps.