GN,
I would focus on when the bullet slows to the transonic threshold as this is where the wobbles start. Up until then everything is fairly predictable although the slower the bullet and lower the BC, the more wind will affect it at all ranges to the target.
This figure from the PRBlog is a good one for visualising when this happens and for how long until the bullet has transitioned back into calm flight. By then, in all liklihood the group size has blown out wider than the linear cone it was before reaching transonic.
[ATTACH=CONFIG]18136[/ATTACH]
Obviously, atmospheric conditions and bullet shape will vary that velocity of 1,340fps, but not by much.
In 1,000yd shooting our 223 bullets would start the wobbles at around 800-900yds. The cross section of group size heading downrange is like a trumpet, blowing out towards the end. Once transonic is reached it becomes more difficult to drive bullets on a target and you get the feeling you have lost some control. They will still hit the target but with less predictability and like they are drunk. In other words your expectations need to be a little more forgiving.
Shooting long range with a Grendel alongside someone with a bigger 6.5 calibre and you are competing with a velocity handicap. You then need them or their equipment to be less capable, or unlucky with wind to even the field. If you are shooting against other Grendels then it's a fairer fight. Barrel length increases velocity so the shorter you go the earlier you are going to reach transonic and the bigger the group will be by the time bullets reach the target. The laws of physics affects Mark Larue the same as everyone else. Shooting is also a game of statistical averages; sometimes you shoot well and other times you don't. Perhaps LaRue was shooting well on that day, or perhaps there something else we don't know about. My point is, if long range is your intention and it has to be Grendel then you don't want to be handicapping yourself any further than the calibre already does, by shortening the barrel and lowering the velocity even further. So, with this in mind there has got to be a more compelling reason to shorten a long-range barrel; like having a compact rifle, or lowering the weight for carry, or wanting it more maneuverable for hunting.
I would focus on when the bullet slows to the transonic threshold as this is where the wobbles start. Up until then everything is fairly predictable although the slower the bullet and lower the BC, the more wind will affect it at all ranges to the target.
This figure from the PRBlog is a good one for visualising when this happens and for how long until the bullet has transitioned back into calm flight. By then, in all liklihood the group size has blown out wider than the linear cone it was before reaching transonic.
[ATTACH=CONFIG]18136[/ATTACH]
Obviously, atmospheric conditions and bullet shape will vary that velocity of 1,340fps, but not by much.
In 1,000yd shooting our 223 bullets would start the wobbles at around 800-900yds. The cross section of group size heading downrange is like a trumpet, blowing out towards the end. Once transonic is reached it becomes more difficult to drive bullets on a target and you get the feeling you have lost some control. They will still hit the target but with less predictability and like they are drunk. In other words your expectations need to be a little more forgiving.
Shooting long range with a Grendel alongside someone with a bigger 6.5 calibre and you are competing with a velocity handicap. You then need them or their equipment to be less capable, or unlucky with wind to even the field. If you are shooting against other Grendels then it's a fairer fight. Barrel length increases velocity so the shorter you go the earlier you are going to reach transonic and the bigger the group will be by the time bullets reach the target. The laws of physics affects Mark Larue the same as everyone else. Shooting is also a game of statistical averages; sometimes you shoot well and other times you don't. Perhaps LaRue was shooting well on that day, or perhaps there something else we don't know about. My point is, if long range is your intention and it has to be Grendel then you don't want to be handicapping yourself any further than the calibre already does, by shortening the barrel and lowering the velocity even further. So, with this in mind there has got to be a more compelling reason to shorten a long-range barrel; like having a compact rifle, or lowering the weight for carry, or wanting it more maneuverable for hunting.