New lot of powder average 37 FPS slower

[6BRinNZ]

Hi,
I have a new lot of ADI 2208 powder that is averaging 37ps slower than the previous lot.
Groups have opened up close to double. nothing else is changed just the powder lot.
ES/SD on the new lot are ok.
How have you brought the load back into tune - just increased powder to get FPS back or left charge the same and adjusted the tuner/ seating depth? I would need to add in approx 6/10ths more powder.
This is Lapua cases ADI 2208 and Berger 185s.

TIA

 

[Dave M.]

Add .2-.3gr of powder to get back to the same speed that was shooting small (assuming you are not currently seeing signs of high pressure).
Dave

 

[leakeyjohn]

I adjust the amount of powder required to achieve the accuracy and or velocity required. Just be happy the supplier of the powder lets us know of lots so we can anticipate that things may change.

 

[Fire Dog]

Been a wet year in OZstralia, especially NSW, perhaps there is a bit more moisture in the mix…??
This has been a subject on this forum back on March 13 2019 by MGYSGT.
Lot numbers on nearly everything from powder, bullets, primers to paint and tiles is always been an indication that there is/may be a slight difference from any other lot made to that same formula.

 

[6.5 forever]

Add .2-.3gr of powder to get back to the same speed that was shooting small (assuming you are not currently seeing signs of high pressure).
Dave

This exactly. All of my components remain the same. I only run one cartridge these days. I use the same barrels. I have found if I match velocity the accuracy stays right in line.