Harry I fully agree with everything you just posted above! However the fact that a 300 yd shot with a BLK 577/450 not being a sporting shot has little to do with the fact that with the 300 yd shot hitting where the sight indicated it will hit, is the point. This is what I was saying the double rifle properly regulated, shooting PROPERLY loaded ammo for the regulation built into the rifle, and with center line of all the sights being in line should tell you that these rifles are NOT regulated to cross shots at any range, and when properly loaded shoot the barrels parallel with the aiming point between the centers of each barrel’s individual groups. Certainly some shots from multiple shots fired at longer range or in fact fairly close range will spill over into the group of the other barrel, because the groups get larger the farther they go down range, as any rifle does. However the centers of each barrel’s individual group remains on it’s own side of the aiming point of the sights.
Loading a double rifle trying to print one ragged hole is not a proper way to load for a double rifle. Simply said, because if they are both hitting one hole, then they are crossing, and by the time they get to 300 yds they will be far apart and the sights would be useless.
Improper regulating loads are the reason most people think a double rifle is useless past the range on the rear sight. Europeans have been using double rifle to hunt mountain game in the alpines for as long as double rifle have been in use. Properly regulated, and double rifle is as accurate as any iron sighted hunting rifle regardless of type! The only difference seems to be that most folks try to apply single barrel technology to a double barreled rifle!
I have a friend that bought his first double rifle chambered for 7x57 Flanged to shoot elk with in Oregon. The rifle had a Quick detach scope in addition to one standing iron for 100 yd and two flip-ups, one for 150 yd, and the last one for 225 yd range He came over to my home saying he had not shot the rifle with the irons, but had simply mounted the scope and tried to zero it in and couldn’t get the rifle to shoot right.
I asked him how he had gone about zeroing the scope to which he replied: “Well I shot the right barrel on the target at 100 yards then adjusted the cross hair over to the bullet hole, as I always do when zeroing a scope. Fired another and the bullet almost hit the same hole cutting it in half ! So far, so good, but when I shot the other barrel it was shooting a little over two inches to the left, so I guess the rifle is not regulated properly or not shooting well with the factory ammo, they said it was regulated with!”
He had made the common mistake most make with double rifles! He tried to use single barrel technology while working with a rifle that had two barrels side by side with the centers of bore one inch apart! He never though about the fact that these two barrels are not going to hit the same hole, and his mistake was not shooting at least two shots, one from each barrel, then adjusting the scope to hit exactly half way between the two bullet holes, then on a new target fire four shots using the same aiming point for all four shots. We did and the rifle was shooting a perfect 2 ½” slightly egg shaped composite group of both barrels at 100 yards. Now all that was needed with to adjust the elevation to place that composite group 2” high at 100 yards, making the point blank range for that rifle holding dead on out to 225 yards, and with a top of the shoulder cross hair to place a bullet in the lungs of an elk at 275 yds.
We later went to a friend’s ranch where he had silhouette range, and placed 8”gong targets at the distances engraved on the irons, and the very satisfying DING, DING, DING sound came from every shot.
Of course that is less likely with a rifle that is chambered for 470NE but it has nothing to do with the regulation, but with the shooter and recoil.