Scratching my head: 7x57 load development

[FlyGuy]

I have sometimes gotten good 7x57 loads with IMR 4064, but USUALLY it all comes back around to 3031.

I've had excellent performance with 3031 using the lighter 7mm bullets, as well as 150gr bullets in .308.
Highly underrated powder IMHO.

 

[ZG47]

The original .220 Swift factory ammunition was loaded with IMR 3031 BUT the large rifle primer pockets had small rifle flash holes, in order to keep pressures down. You do what you have to, whilst waiting for the right product to enter full production.

 

[7x57Joe]

I've had excellent performance with 3031 using the lighter 7mm bullets, as well as 150gr bullets in .308.
Highly underrated powder IMHO.

IMR-3031 is also good with the heavier bullets and gives good accuracy. I've used it with 175 grain Winchester Power Point bullets getting 2350 fps from my 22" barreled M.98. No pressure signs and cases reloaded 8x.

 

[Rare Breed]

Interesting....I just finished reloading and shooting my 275 Rigby with my 175 grain Nosler Partitions. They clover leave like my 140 grains. The key I found was in COAL. My 140 grain was 2.83 and my 175 grain was 2.89. When you read any reloading manual, they recommend about 3.045 which did not group well at all for me.