Range Report Lee 457-340 grain cast bullets
Posted: Fri Aug 02, 2019 4:42 pm
As hard as I tried to love the 500 grain cast bullet from the Lee 90577 mold, it was just not accurate enough for how much work it involved. It also barely functioned the gun and used up a lot of my lead. I figured it was time to try another mold, this time a little closer to my hunting load. Up front, the Lee 90373, 340 grain .457 bullet is easy to cast, sizes down to .452 without difficulty, doesn't use as much lead, and cycles the gun. We're off to a good start.
Still using the same gun:
18" AR15 GLFA barrel, mid gas, 1:24 twist
The bullet:
Lee 457-340 2 cavity aluminum mold
Dropped at 340 grains with straight wheel weights
I found that since they have a nice flat nose, I can cast, powder coat, then size the bullet upside-down in the Lee die, and I don't get the base deformations I got with the 500 grain bullet. This saves me a ton of time from sizing, sanding, coating, then sizing again. For these first bullets I used WW with added lino, water quenched after PC. Seated to 2.1", taper crimped. I made these harder bullets in anticipation of higher velocities.
I first started with 34 grains of Shooters World Blackout. Two of the three cycled, I didn't get any chrono data because I got rained out. The cases were nice and clean.
Next moved up to 35 grains. Perfect cycle on most of them. I did have an oddball velocity that didn't cycle.
1698
1545
1641
1693
1700
1648
I'm discounting the 1545 fps shot as it's so far off from all the others. This brings the avg velocity to 1675.
As you can see there's room for improvement. My hunting load is a 300 grain XTP with 40.5 grains SWBO, so I have some room to increase velocity. I can also try softer or harder lead. After that I'll probably try some H110. Either way, it hits almost the same zero as my hunting load, which is a plus. I don't have to make special concessions with this bullet like buffer spring strength or buffer weight like I did with the 500. So far I'm happy for a plinking load, now it's time to refine it.
Comments/critiques/criticism welcome.
Still using the same gun:
18" AR15 GLFA barrel, mid gas, 1:24 twist
The bullet:
Lee 457-340 2 cavity aluminum mold
Dropped at 340 grains with straight wheel weights
I found that since they have a nice flat nose, I can cast, powder coat, then size the bullet upside-down in the Lee die, and I don't get the base deformations I got with the 500 grain bullet. This saves me a ton of time from sizing, sanding, coating, then sizing again. For these first bullets I used WW with added lino, water quenched after PC. Seated to 2.1", taper crimped. I made these harder bullets in anticipation of higher velocities.
I first started with 34 grains of Shooters World Blackout. Two of the three cycled, I didn't get any chrono data because I got rained out. The cases were nice and clean.
Next moved up to 35 grains. Perfect cycle on most of them. I did have an oddball velocity that didn't cycle.
1698
1545
1641
1693
1700
1648
I'm discounting the 1545 fps shot as it's so far off from all the others. This brings the avg velocity to 1675.
As you can see there's room for improvement. My hunting load is a 300 grain XTP with 40.5 grains SWBO, so I have some room to increase velocity. I can also try softer or harder lead. After that I'll probably try some H110. Either way, it hits almost the same zero as my hunting load, which is a plus. I don't have to make special concessions with this bullet like buffer spring strength or buffer weight like I did with the 500. So far I'm happy for a plinking load, now it's time to refine it.
Comments/critiques/criticism welcome.