Results 11 to 15 of 15
Thread: rht sight question..
-
16-04-2018, 10:33 #11
- Join Date
- Apr 2011
- Location
- JHB North
- Age
- 48
- Posts
- 3,951
-
16-04-2018, 12:11 #12
- Join Date
- Oct 2012
- Posts
- 107
Re: rht sight question..
It's impossible for the POI to change by 5 inches at 10m by changing the height of the front sight by 0.03 inches, or 0.762mm. Best to work out the change in POI yourself.
Ignoring bullet drop (which is a valid assumption for short to medium distances) the following relation holds:
[(change in height of front sight)/(sight radius)]=[(change in POI)/(distance of shot)]
Taking the G34 as example, the POI will change by 4cm at 10m, and by 10cm at 25m. The change is bigger the smaller the sight radius, but it is still only 5.6cm at 10m and 14cm at 25m for the G26.
-
16-04-2018, 13:15 #13
- Join Date
- Aug 2012
- Location
- The moral high-ground
- Age
- 52
- Posts
- 3,001
Re: rht sight question..
If we managed to actually measure the difference between the front sight that I initially had on my G21 and the one that replaced it your calculation would be of value. But we didn't...
With the tall front sight (which is visibly a lot taller than the lower one) my gun would print just above the bottom of the 8 inch zero down circle of an IDPA target with my point of aim the top of the circle at 10 meters. I would call that about 5 inches give or take. With the lower front sight I am hitting the top of the line if I aim at the top of the line. This means the shift in impact is...5 inches (give or take). The calculation may be sound but it will only be relevant if you recorded the actual measured heights of both sights.
What comes from the engineering shop and what you read in the brochure isn't always the same thing. Read the part of my post about the rear sight they replaced for me because it was out of spec...
-
16-04-2018, 13:38 #14
- Join Date
- Oct 2012
- Posts
- 107
Re: rht sight question..
So, for the POI to change by 5 inches at 10m, the height difference of the front sights must be 2,17mm, but it is specified to be 0,762mm. That is more than simple "manufacturing tolerance" or "out of spec." Even if, by chance, you got two front sights that are so far out of spec, it does not help the OP.
Look, the physics and math is what it is, you can't shoot better than that.
-
16-04-2018, 13:46 #15
- Join Date
- May 2014
- Location
- JHB
- Posts
- 2,657
Bookmarks