Post by Century2 on Oct 23rd, 2009 at 12:42pm
I originally posted this back in May however it was lost in the forum restoration. :'( Here's the abbreviated version:
For your viewing pleasure I have attached my drawing of the “perfect” Krag front sight. While this “perfect” sight may be beautiful on a museum specimen, it’s not a lot of good with modern ammo at the range. The front blade height of 0.410” was designed for the 220-grain USGI bullet at 2000fps. Unless you can handload perfect USGI loads or have “pet loads” that somehow get a similar trajectory, a sight adjustment will probably be necessary if you would like to hit a much smaller than man-size paper target. I inherited a case of factory Remington ammo - here’s what I found when you use standard hunting ammo in a 100-year old battle rifle and play marksman: With my 1901 sight in the down (lowest) position, it strikes the target about 3.5” high at 100-yards. To move the strike 1” at 100 yards, the Krag front sight needs to change height by .0068” (correlation solved graphically). I fabricated a front blade at .4340” [0.410” + (3.5 times 0.0068”)] and am grouping nicely on the target. I tested the same 1901 sight on three different rifles manufactured in 1898, 1901 and 1902 with different front sights and the correlation checked out. A few of you may find the following facts interesting: Brophy’s book added 0.003 to the front sight height (0.413” in lieu of 0.410 in Poyer) – this would lower the strike about 1” at 200 yards. The 1902 rear sight is 1.75” closer to your eye than the 1901 sight and .121” lower in full down position. Studied graphically, the 1902 front sight should strike about 16.5 inches low with a 0.410” front blade. To correct this, a lower (say 0.289”) front blade may be required.
050409_KRAG_BLADE.JPG ( 61 KB | 5
Downloads )
For your viewing pleasure I have attached my drawing of the “perfect” Krag front sight. While this “perfect” sight may be beautiful on a museum specimen, it’s not a lot of good with modern ammo at the range. The front blade height of 0.410” was designed for the 220-grain USGI bullet at 2000fps. Unless you can handload perfect USGI loads or have “pet loads” that somehow get a similar trajectory, a sight adjustment will probably be necessary if you would like to hit a much smaller than man-size paper target. I inherited a case of factory Remington ammo - here’s what I found when you use standard hunting ammo in a 100-year old battle rifle and play marksman: With my 1901 sight in the down (lowest) position, it strikes the target about 3.5” high at 100-yards. To move the strike 1” at 100 yards, the Krag front sight needs to change height by .0068” (correlation solved graphically). I fabricated a front blade at .4340” [0.410” + (3.5 times 0.0068”)] and am grouping nicely on the target. I tested the same 1901 sight on three different rifles manufactured in 1898, 1901 and 1902 with different front sights and the correlation checked out. A few of you may find the following facts interesting: Brophy’s book added 0.003 to the front sight height (0.413” in lieu of 0.410 in Poyer) – this would lower the strike about 1” at 200 yards. The 1902 rear sight is 1.75” closer to your eye than the 1901 sight and .121” lower in full down position. Studied graphically, the 1902 front sight should strike about 16.5 inches low with a 0.410” front blade. To correct this, a lower (say 0.289”) front blade may be required.
050409_KRAG_BLADE.JPG ( 61 KB | 5
Downloads )