My favorite kind of fireworks on The Fourth of July: fine tuning some loads at the range, and helping the young whippersnappers get their AR-15's sighted in. It was 94 degrees F at the range today. Hot.

470 MBOGO 25" barrel
The 470 Mbogo needed an X-Bullet load to fill its case:
Quality Cartridge brass, F-215 primer, 500 grain XLC, RL-15 powder, three shot average with each powder charge ...

108 grains ... 2526 fps (13 fps ES)
109 grains ... 2552 fps (14 fps ES)
110 grains ... 2561 fps (3 fps ES)

I have found my 470 Mbogo SP load. 110 grains with the XLC just fills the case and makes one hole groups at 50 yards, but what a small little step for that last grain of powder!? (Statistical insignificance from small sample size and funny numbers ... in the previous two loads, surely not the 110 grain load!) Now on to scope mounts and stock finish!!!

45 Lapua 25" barrel
This one needed some 350 grain bullet velocity-exploratory loads:
Lapua Brass, F-215 primer, 350 grain Hornady RNSP, RL-15 powder, 3 shot average with each powder charge ...

100 grains ... 2649 fps (ES 21 fps)
101 grains ... 2674 fps (ES 16 fps)
102 grains ... 2693 fps (ES 8 fps)
103 grains ... 2736 fps (ES 45 fps)
104 grains ... 2738 fps (ES 14 fps)
105 grains ... 2762 fps (ES 8 fps)
106 grains ... 2779 fps (ES 11 fps)
107 grains ... 2799 fps (ES 5 fps)

Now I might do this with 350 grain X-Bullets.

A problem: The 500 grain bullets at 2450 fps shoot to POA at 50 yards, but the 350 grain bullets shoot 8" higher at 50 yards, iron sight for both, and ne'er the twain shall meet.

A separate rifle for each load? An iron sight zero for the 500 grainers and a scope zero for the 350 grainers if only one rifle is to be used? Or slow the 350 grainers down to shoot only a bit higher than the 500 grainers? That would be the gentlemanly solution. Now on to a 22" barrel for an easy 2400 fps with 500 grainers and 2700 fps with 350 grainers.

The heavier bullets and 100% loading density gives the most uniform results with both of these cartridges.

After thought: Maybe I mixed up the cartridges in the 103 and 104 grain charges of the 45 Lapua, or had a bad reading, a high one, on one of the 103 grain shots? Yep, the latter: 2724, 2720, and 2765 ... for the 103 grain charges. Throw out that one 2765 reading and things make more sense.

[ 07-07-2003, 04:11: Message edited by: DagaRon ]

Hi Ron,
Sounds like you've really found the "Mother Load" with your 470. I think you should post some pictures of your bad boy. Anything that shoots that well can't be ugly.
Take good care,
Dave

Dave,
Actually it is one of the most ruggedly beautiful rifles I own. Utterly indestructible stock-wise, with 3 visible cross bolts, one hidden crossbolt, and hidden 1/2" thick steel axial bolt through the grip/wrist. It may not be "pretty" but it is ruggedly beautiful to my eye.

It is the kind of rifle to sleep with on Kodiak Island when the bears have been sniffing your tent on moonless nights, or to wander the African veld with all-sufficiency from the All Father.

It has a lightning bolt checkered on each side of the laminate stock forearm, painted over with clear epoxy to retain some texture and prevent the checkering from flaking off. A buffalo skull and horns silohuette is inlaid in black epoxy on top of the right side lightning bolt, as well as a stylized hammer of Thor, in brown and silver epoxy, bonking the bull on the horn tip, all in bas relief.

When I grasp my 470 Mbogo, I am grabbing the bull by the horns and wielding the hammer of Thor at the same time.

I am about to disappear for a few days. Work, you know. Will post pictures one day, at my convenience, if anyone cares.

Aloha.