Here is a couple of animals I have taken the last two weekends at what would be considered long-range.
First, is a medium sized Mule Deer I took yesterday at 600 yards.
Wind was running from 7-8 mph on this shot.
Second is an "uncommon doe" antelope I shot the last Saturday in September at 420 yards with a 10mph full value wind.
Both animals were taken with my rear-grip XP-100, McRee stock, Leupold Mark 4 FFP 6.5-20 with ART Reticle, Barrel and chambering were from McGowen. Brake is Holland's Radial Muzzle Brake. Bullet is the Berger 140 grain VLD. Chambering is the 6.5-284. Federal match primer, Lapua brass, and Hodgdon's Hybrid 100V. Both shots were taken from the prone position, using a Harris BR Bi-pod (notched legs) with Pod-Lok. I use a small leather bag under the pistol grip filled with corn cob media.
Using the 6.5-284, which is about the same as a 260 Rem in a rifle is definitely more challenging than shooting my 7mm Dakota or my new 338 barrel that will share the same action in the future.
The wind has to be more spot on and the other thing I am being reminded is how a little swell in the ground can throw you off of your true distance to target. My shots went low on the mule deer because of such an issue yesterday. It is moving me to know the width of the beam at various yards, and also will be one of the factors of it is a "go" or "no go" when it comes to pulling the trigger. The laser read consistently the same distance, but it was consistently short. The good thing was that the difference did not keep me from missing or even worse, wounding an animal that could not be recovered.
Also, I wish there was a way to get my Kestrel high in the air while being able to read it while prone for more accurate data at my position while not alerting game.
In reality, I think it was my new blaze orange LRH Cap that made the difference on the mule deer though