270 wsm long ranger ballistics
i am asking for my father who is leaving tommorrow for a caribou hunt. sighted in a dead-on 200yards what would the drop be for a 150 grain boat tail out at 600, 700, and 800 yards? the rifle is a kimber that i bought him for the hunt cause he can't walk far so i want to give him the "reach". if anyone is on by 11:00 am est sunday that can help i would be thankful. i just found that he doesnt know the drop beyond 500. he also has a leupold 6x14 i think it is that will get him to 500 dead-on.
Well this is a day late and maybe a dollar short. In the future, you will need more info to determine your bullet drop at the ranges mentioned. You'll need to know the MV and BC of the bullet you're using.
Probably 2 of the best "hunting" bullets out there for the 270 are the Nosler 140 gr AB with a BC of .496 and the Nosler 130 gr E-Tip with a BC of .459 The 140 AB gets an expected/advertized MV of about 3200 fps and the 130 E-Tip gets about 3300 fps. Their ballistics are almost identical with a very slight edge going to the 140 AB. Both make it to 800 yds with just over 1800 fps of velocity and 123 - 126 inches of drop when zeroed at 200 yds. The 140 AB (with a greater SD) will have 36 lbft of momentum and the 130 E-Tip about 33 lbft. 1800 fps is the minimum performance vel for these bullets to ensure expansion. Beyond that they will probably pencil hole through the animal. That would work on an antelope but I would not try it on a caribou.
Based on this I would use the most accurate bullet in my rifle and go with the AB if they were the same accuracy.
Having said all that, a lot of this info is assumed and should always be verified by actual shooting at known ranges. I personally wouldn't shoot at an animal at a range that I haven't already fired my rifle to both check the ballistics of the cartridge and to check the capability of the rifle and myself. Most folks with a good rifle can shoot out to 300 yds. Beyond that the variables start getting significant, such as estimating distance, windage, holding steady in field conditions, etc. Beyond 300-400 yds, exact range and windage must be known to make a confident shot on any target. I personally would not make a long range shot without confirming the disance with a range finder. At 400 yds, a 50 yd miscalculation will result in a POI difference of 7" and at 500 yds the diff would be 11" with this cartridge. Also, most long range shooters use a scope that allows you to dial in your windage and elevation so there is no guess work on hold over or mil dots.
When you start shooting beyond 500 yds, it will take some practice and the farther you shoot the more practice needed.
Here's an online ballistics calc
Hope this helps
Sighting in dead-on at 200 really cuts into long range trajectory. I'm not using the WSM, but with my 270 Wby dead on at 200, I'd be low at 300 and getting way lower beyond that. I can't imagine where the dead-on at 500 comes from.
Originally Posted by johnboss
My normal sight in for LR performance with this rig is 4" high at 100, which puts it about 5" high at 200, 3" high at 300, dead on at about 340, 3-4" low at 400, and I'd guess around 12-15 low at 500. The last is theory because I haven't shot it much past 400. As for 600, 700 and 800 yards? We're talking "minutes of caribou" hold overs.