T Inman,
Have mentioned this before, several times, on the Campfire, but if a bullet groups well at 100 yards it will group well at longer ranges, because contrary to popular belief they do not "destabilize" at normal hunting ranges (even, say, beyond 400 yards) just because velocity drops.
But there are other reasons they can shoot less accurately. First (and probably foremost) is wind-drift, which increases at about twice the rate of range.In other words, if a bullet drifts two inches at 200 yards in a certain wind condition, it will drift about 8 inches at 400 in the same conditions.
Another reason is parallax in the scope, combined with inconsistent head position behind the scope.
Yet another is inconsistent shooting.
But there is NO ballistic reason for a certain bullet to group "bigger" at longer ranges other than wind or parallax.
There was recently a long thread on "Ask the Gunwriters" about this, where a guy was shooting sub-inch groups at 100 and 3-5" groups at 200. He could not figure it out, until somebody suggested one of the sling swivel studs might be hitting the sandbags during recoil. Which turned out the be exactly the case, after hundreds of posts and lots of suggestions.
I am no ballistics expert, nor a physicist, no doubt. I'll take your word for what you wrote, and I do appreciate the response.
Maybe I got into some bad lots, maybe it's a coincidence, maybe it's bad luck...I dunno but one rifle in particular that I was having these fits with the accubonds, shot the ELD-M awesome at distance, so I can't totally believe parallax or my head position was the issue. The bullets were the only variable, besides small variations in powder charge to keep within book loads. Maybe that had something to do with it? This wasn't the only rifle I had this issue with...
I think I'll give the accubonds another try, just for the hell of it. I do know that when my stash of old style 200 grain grand slams is out, I plan to use the 200 grain accubonds in my .300 H&H. I have it scoped with a standard duplex and no turrets so I have no intention of shooting it at longer ranges. I fully expect the 200 grain accubond to be superb in that rifle, if it isn't too long to fit in the magazine when seated where it needs to be.
