Richard.
The overall length of my loaded rounds is 3.225 inches and the base to ogive including a Sinclair Caliper comparator is 3.530 inches. The comparator measures 1.109 inches. These rounds jam about 0.010 inches in a 0.276/0.284 barrel. I have another newer barrel where the base to ogive measurement in 3.520 inches again jammed about 0.010. The bullets are Berger Thick 180gr VLDs trimmed and pointed to 1.500 inch overall length. I found that the 3.520 base ogive dimension is necessary to keep the boattail junction out of the donut area of the case neck. My reamer is the same one as the print on the 7mm Cartridge Guide but I have my gunsmith lenghten the throat an extra 0.020 inches to avoid the donut. I did extensive testing of seating depth using Jason Baney's round robin method and found the 0.010 to 0.015 jam to give consistently better vertical and minimize flyers. Off the lands 0.010 might give 2-3 inches of vertical at 300 yards where jammed 0.010 to 0.015 would consistently give under 3/4 inch vertical at 300. These rounds give consistent X-ring vertcial at 1000 yards under F-Class match conditions.
The overall length of my loaded rounds is 3.225 inches and the base to ogive including a Sinclair Caliper comparator is 3.530 inches. The comparator measures 1.109 inches. These rounds jam about 0.010 inches in a 0.276/0.284 barrel. I have another newer barrel where the base to ogive measurement in 3.520 inches again jammed about 0.010. The bullets are Berger Thick 180gr VLDs trimmed and pointed to 1.500 inch overall length. I found that the 3.520 base ogive dimension is necessary to keep the boattail junction out of the donut area of the case neck. My reamer is the same one as the print on the 7mm Cartridge Guide but I have my gunsmith lenghten the throat an extra 0.020 inches to avoid the donut. I did extensive testing of seating depth using Jason Baney's round robin method and found the 0.010 to 0.015 jam to give consistently better vertical and minimize flyers. Off the lands 0.010 might give 2-3 inches of vertical at 300 yards where jammed 0.010 to 0.015 would consistently give under 3/4 inch vertical at 300. These rounds give consistent X-ring vertcial at 1000 yards under F-Class match conditions.
