Thread: Velocity Loss From Summer to Winter.

Originally Posted by sneeze

James did you validate your original velocity at decent ranges? and what distances where you shooting last weekend to determine the velocity loss?

Thanks for the idea Sneeze,

I only validated the 'Summer' speed out to 550yds- is that enough??

Last weekend I tested at 400yds, 600yds, 800yds and 1000yds. Only shot 5 rounds per distance. But it held sub 0.75 out to 400, and sub 1.0 beyond that (a lot of good fortune involved at 800 and 1000 though ). So I would've thought that was a pretty good sample?

Keen to hear your thoughts.

Originally Posted by James

Thanks for the idea Sneeze,

I only validated the 'Summer' speed out to 550yds- is that enough??

Last weekend I tested at 400yds, 600yds, 800yds and 1000yds. Only shot 5 rounds per distance. But it held sub 0.75 out to 400, and sub 1.0 beyond that (a lot of good fortune involved at 800 and 1000 though ). So I would've thought that was a pretty good sample?

Keen to hear your thoughts.

Normally Id say a 90fps drop was highish for an ADI powder but a range of things will have an influence.Firstly at 550yds a 90fps difference is less than 4 inches( aprox) which can be hard to determine when all the other anomallies are taken into account. It sounds like you have enough info for your current velocity and BC but the summer speeds might need some more work? It may well end up at a 90fps difference but I dont think you can confirm it yet. Chronys are becomming a pet hate of mine , to many people read the numbers on them and take them as gospel. The shooting chroneys are just not accurate enough and at times can give large variations due to nothing more than a change in light ,if you use them and put enough rounds over them then you start to see a trend ,or just use them as a rough guide .The ohler definatly is a step up but a lot of money and you stil have to validate shoot anyway. The CED 2 is a reasonable comprimise with the IR screens. cheaper, easier to set up and gives good info but the best chrony/balistic programe, quickload etc will always be a poor second to holes in paper at range.

Originally Posted by sneeze

Normally Id say a 90fps drop was highish for an ADI powder but a range of things will have an influence.Firstly at 550yds a 90fps difference is less than 4 inches( aprox) which can be hard to determine when all the other anomallies are taken into account. It sounds like you have enough info for your current velocity and BC but the summer speeds might need some more work? It may well end up at a 90fps difference but I dont think you can confirm it yet. Chronys are becomming a pet hate of mine , to many people read the numbers on them and take them as gospel. The shooting chroneys are just not accurate enough and at times can give large variations due to nothing more than a change in light ,if you use them and put enough rounds over them then you start to see a trend ,or just use them as a rough guide .The ohler definatly is a step up but a lot of money and you stil have to validate shoot anyway. The CED 2 is a reasonable comprimise with the IR screens. cheaper, easier to set up and gives good info but the best chrony/balistic programe, quickload etc will always be a poor second to holes in paper at range.

Good info. Thanks for your help Sneeze.
Yeah, drop was just over 4 inhes at 600 so that fits. The variability of the chrony is becoming obvious- I'll go forward just using it as a guide to get me on the paper, and validate from there.