Wild velocity spread with ramshot big game

[baldhunter]

It's your chronograph.The angle of the sun can cause the optical eyes to give false readings.I've run into this many times.It doesn't take much.The units are calibrated to see the bullet at a precise distance,like exactly one foot between the first eye to the second eye.If there is a shadow across the eyes,it could read the bullet at a distance say 11-15/16" instead of 12".Just that small fraction could be equal to a couple hundred foot per second.

 

[JAYgs8163]

UPDATE!
Went to the range about an hour ago (about 80°) and got all set up with the chronograph.
I shot 3 factory Remington loads through it (150 cor lokt) and they chronographed 2920 average, right where they should be.

I then shot a ladder test with my 215 bergers and imr 4831, 56.5gr yielded 2790fps no pressure signs other than a slight ejector mark.

I then shot the problematic 150fmj load... 3066 fps with a literally frozen cartridge (in rapped it in an ice pack while shooting other loads) and 3090fps with the same load left out in the sun while I shot.

My conclusion is that the chronograph was too close to the muzzle and or the concussion from shooting under cover was messing with the chronograph.

Thanks for all the ideas and help!!!!




Pictures are of the 215s

The problem is that you don't have a Garmin Xero.

 

[Budget'06]

The problem is that you don't have a Garmin Xero.

Good chronographs are a bit pricey

 

[JAYgs8163]

Good chronographs are a bit pricey

So is burning through Powder, Primers, projectiles, and brass with no good data you can rely on.

 

[skipglo]

since last time i shot it, about 25-30 degrees. hard to beleive that it would jump several hundred feet per second tho. i expected 3100 in the hotter weather.

Absolutely no doubt on heat.....and no surprise either.....with powders that are not temp stable I've seen 48. fps change in 6 degrees difference

 

[skipglo]

3300fps with a 150 is 300 weatherby territory... the 3050 i was getting was about what most books said id get. I feel like it was a chronograph issue but im not sure why it would then read another load at a velocity that seemed perfect... i dont have access to another chrono, ill have to look around to see if someone has one

You mean you don't shoot a Weatherby??????? I guess there is another manufacturer out there!