I have the BR2 and the SIG 2400. I live in both Arizona and CO; my Colorado place is 8750; I am there now and shoot at gongs several times daily. The SIG does correct for elevation pretty darn well. At 715 yards my change is about 1 MOA less elevation; I don't know what it is at 905 because I go from 860 to 1200 in Arizona.We live and shoot at 2800 elevation. We hunt at 8000 elevation. I haven't kept a log sheet through the years like Im doing now. But I do know that every trip, my buddies shoot high when we test our rifles before we hunt. I always did too, until I bought the BR2 rangefinder. Whether it does what its suppose to do, and adjusted my hold for higher elevation( I will discuss this more in a second). Or I was lucky could be argued I guess. But while my buddies shot multiple shots adjusting their setups, I fired 2 shots. One at 450ish- direct hit. One at 1300ish- half moa left. Cant remember the exact yardage, shooting at rock faces. And I was shooting my 7mm Allen mag at the time if anyone wondering. So gauging from my experiences, plan on adjusting your scopes once you arrive.
More about rangefinders....
I sold my BR2 and purchased a sig sauer 2400ABS because its more compact. And haven't taken it out west yet. However, shooting and getting my data at home at 60 degrees. Then shooting again at 30 degrees. My sig sauer didn't compensate adequately. I didn't chrono my rifle at 30 degrees, like I did at 60 degrees. But according to my drop data(using very good groups). It appears my gun shot well over 100fps slower. Dropping 1.5 MOA more at 615 yds than when shooting at 60 degrees. My gunsmith, which is a successful competition shooter logs all his shots. He tells me than for every 10 degrees in temperature change, he dials differently for same yardage( about .5 MOA per 10 degrees). It looks to me like my BR2s did that for me. But the Sig sauers aren't. And testing RFs one another day, I ranged 557 yards out my door with Rf temp at 73 degrees. Which was my temperature in my house. Zero angle. Then I hung my RF outside for awhile. Then ranged same target at 38 degrees. and with temps rising that day to almost 50. I ranged again at 40, and again at 50. At 73 degrees it said 8.58 MOA. At 38 degrees it said 8.65 MOA. So .07 change in 35 degree swing. Not even close to what I've experienced while shooting. Or what my gunsmiths data suggests.
Even though I've been shooting long-range for years, It seems like the more I learn the harder it becomes. I'm definetly keeping a log going forward of every shot I fire. Temperature, humidity, what my RF tells me to dial, shot angle, and actual bullet impact. The more I shoot, the harder it seems to be to get a first round 1/2-3/4 MOA direct hit from one day to the next.
Any suggestions on why my sig sauers didn't compensate adequately? Will this RF account for pressure from 2800 feet to 8000 feet like Im assuming the BR2s did?
I'm aware I didn't really answer your question. But figured maybe someone could shed some light on why my RFs aren't adjusting properly. And maybe open the door to you purchasing a RF that elimates the issue you are questioning.
I reread your post; you said your MV dropped 150 fps; that is really significant. I once tested spherical powders in hot/cold and got over 100 fps difference, but the temp was pretty drastic. Are you using spherical powders?Thats good info to hear. Appreciate the feedback. And idea why my gun wouldve dropped 1.5 moa more than from previous outings?
Barometric pressures and humidity plus elevation will be your biggest concernWe are preparing for a mule deer and antelope hunt. Our home shooting range is approximately 3200 ft elevation, and the hunt area averages 6300 ft. My question is how much will the elevation change affect point of impact. Rifles will be zeroed at 200 yds.