LEE 379-250 Hardness

[HPT]

A few weeks ago, I did a lot of shooting with the LEE 379-250 made from pure WW and was getting several 5 shot groups of less than 2-1/2". These bullets were probably a few years old. The load was 42gr FFG Goex w/wads. I was using the barrel sights

Yesterday, I did a lot more shooting. The bullets were all LEE 379-250 made from 25% pure lead, 75% WW (from the same mold as before) and were a couple weeks old. The load was exactly the same 42gr FFG Goex (same can) w/wads. Again I was using the barrel sights

A friend was also shooting the same gun and got the same results: Groups twice as big as last time.

So, the hardness was less for sure other than that the only other difference was that the first day was sunny & Yesterday was cloudy.

Any out there with similar results - bevel base bullets shooting worse with softer bullet?

Any out there with similar results - better groups on sunny days using open barrel sights

[missionary5155]

Greetings
You did not mention what rifle ...
BUT I would guess your throat area is larger that the boolit you are shooting. By switching mix you probably have also reduced the boolit diameter. That might explain the WORSE accuracy. Lead cast LESS diameter than WW. With Black I would cast near pure lead as Black will bump up the boolit some. But I would still cast ThROAT DIAMETER + .
I would measure the throat area and be sure your cast booñit is that diameter +.001.
In my Winny 35-55 the throat measure .380+. I cast my 50/50 ww/lead boolits to .381+ and it will shoot 2.5"- 3" at 100 yds.. ususally.
Marlins NEED FAT boolits generally. So again Measure !
Mike in Peru

[Trailblazer]

I don't do as well on cloudy days as I do on sunny days. I just can't see the sights as well in lower light.

[HPT]

Thanks for the responses.

Missionary 5155,

The rifle is a Winchester and the rifling is .379 groove dia. but I don't know the throat dia. The current bullet is mostly .380 dia (some parts measure .379). The WW may have been 1/2 to 1 thou larger. These were from a single cavity mould. I had experienced tumbling with the Lyman bullet @ .377 dia so maybe I'm on the borderline with the .380 and .381 would be better. I picked up a new 2 cavity LEE mould, maybe it will make bigger bullets

Trailblazer,

What do you suggest for a target? I'm using a 10"white circle with a black background.