The Rifleman's Front Sight

[SamD]

Hey Dirty Bill.
Her is teh key to remembering the MOA.
An MOA ian't 1" at 100 yards it is 1.0471996" at 100 yards. After you cuss yourself silly trying to remember that figure, 1" is easy 

Sam

[Geddys Uncle]

*whisper voice on*.....to use the front-sight post as a ranging device requires that sometimes, the muzzle might be pointed at something that mightn't need to be destroyed within the next 3-4 seconds.....so, well....don't let the neighbors see you estimating range that way *whisper voice off*......


actually, the front-sight range estimating can be a useful tool while developing your distance-eye....or further convincing your neighbors that you are, indeed, depending on your zipcode and demographic, either a loon, or a guy who takes his riflery seriously

[gjwilliamsjr]

*whisper voice on*.....to use the front-sight post as a ranging device requires that sometimes, the muzzle might be pointed at something that mightn't need to be destroyed within the next 3-4 seconds.....so, well....don't let the neighbors see you estimating range that way *whisper voice off*......


actually, the front-sight range estimating can be a useful tool while developing your distance-eye....or further convincing your neighbors that you are, indeed, depending on your zipcode and demographic, either a loon, or a guy who takes his riflery seriously

If my neighbor across the street knew how many times I've "shot" the license plate on his truck, he would be very unhappy with me 

[Geddys Uncle]

If my neighbor across the street knew how many times I've "shot" the license plate on his truck, he would be very unhappy with me 

   no contact, no foul......when the subatomic physics guys complain that the neutrinos are starting to leave holes, your neighbor will have bigger things to worry about. 

[Whisker]

I got the chance to do some real distance shooting over the weekend.  I posted two 20" silhouettes out on two different hills, one further than the other.

When I got back to my firing point, I tried a range estimation. 

The first silhouette was just under my front sight width.  I had done some math the night before, and according to my sight radius and sight width (.072") I have an 8moa front sight.  This makes sense.  A 20" target at 250 meters will be 8 MOA wide.  However, the closer target was between 1/2 and 3/4 the size of my front sight.  I clicked up 2 clicks past my 200 yard setting and let fly.  (Now I realize the mistake and should have clicked up more)..

I then shifted NPOA to my further target.  It took up about 1/3 of my front sight.  I clicked up to my 600 yd zero and fired a five round group.  I called all the shots good.  No dirt splashes.

Unfortunately, upon checking the targets, the further silhouette had no holes.  Not even in the surrounding cardboard.  I could find no scrapes in the dirt as it is thick prairie grass.  Hmm..

The closer silhouette also had no holes..  In the dirt in front of the target were my bullet scrapes, aprox 40 inches below impact zone.  So, I had underestimate my range...  It was strange because I felt like this target was only 250 meters or so away, and I thought clicking to 300m would be overkill.  I also thought the further away silhouette was only 500m away.  Of course, this could not be the case if it took up 1/3 of my front sight, (2and2/3 moa) 

Feeling somewhat discouraged (and out of time) I packed up and considered buying a range finder.

Maybe the landscape threw me off.   It was a series of rolling hills (Iowa)... Maybe I wanted to believe that 500m was really really far off, when it didn't seem so.  Maybe my calculations are wrong.

I like the idea of having the skill to do the job without fancy equipment.  Of only needing to have my rifle to make shots. . . But at this point, it seems too chancy. 

It seems that making estimations like "my target is 1/3 of my front sight" is very prone to mistakes.  Perhaps this can be corrected by doing more unknown distance shooting.



Thoughts?

[JoeZ]

3/4 (6 moa) of your front sight is 330 meters distant. (20" / 6moa = 3.3 x 100)
1/2 (4 moa) of your front sight is 500 meters distant. (20" / 4moa = 5 x 100) If 20" is full width at 250(BSZ), half the sight is 2x the range or 500.
1/3 (2.67 moa) is 750 meters.  (20" / 2.67moa = 7.5 x 100)


My scope has a built in moa range finder. It works amlost identical to your front sight. Be patient and practice as you almost have it. I take my laser range finder with on exercises to double check my work.

[CaptG]

I've taken my rifles out to the 25m range in the pasture & looked at a QDAQT. Using the different size targets tells me at what range the front sight with equals 20 inches/4 MOA.
Guy

[Francis Marion]

I got the chance to do some real distance shooting over the weekend.  I posted two 20" silhouettes out on two different hills, one further than the other.

When I got back to my firing point, I tried a range estimation. 

The first silhouette was just under my front sight width.  I had done some math the night before, and according to my sight radius and sight width (.072") I have an 8moa front sight.  This makes sense.  A 20" target at 250 meters will be 8 MOA wide.  However, the closer target was between 1/2 and 3/4 the size of my front sight.  I clicked up 2 clicks past my 200 yard setting and let fly.  (Now I realize the mistake and should have clicked up more)..

For quick mental math purposes, let's equate yards with meters.  Your 8 MOA front sight should match the 20" target width at 250m... 8 MOA times 2.5 "/MOA is 20 inches. 
Working from the known to the unknown, we know now that the 8 MOA front sight, the 20" target, and 250 meters are a matching set of information, a "battle sight zero" if you will. 
The near target was between ½ and ¾ the width of the front sight.  So, the target range is estimated as
(the reciprocal of 1/2) times 250 meters, which is 2 * 250 meters, for a range estimate of 500 meters.  Not going to hit that with a 200 m elevation plus two clicks.  The come-ups for a 30 cal from 250m to 500m would be roughly 1 ½+ 4+4 for a total of 9 ½ clicks above the 250m setting.  So 200m elevation plus two clicks wasn't enough. 
And if that near target was ¾ the width of the front post, the range is estimated as (reciprocal of ¾) times 250 meters, or 4/3 times 250 meters or 333meters.  The come ups from 200m to 333 for a 30 cal rifle would be I'd estimate 3 +2 for a total of 5 clicks.
So still a little low.  The range estimation is only as good as your set of assumptions (front sight width, target size) and the shooter's judgement (ratio of target to front sight width).  This is a give and take exercise, at the expense of high precision, the simple fractions give you a chance to estimate range quickly by mental calculation.  If you have the luxury of time, and a pocket calculator, you can assign the target a more precise ratio to the front sight post.  But the idea here is not to establish range with the precision of a laser, but to estimate range with an educated guess with such tools (front sight and brain) as are available to any person who shoots a rifle.

I then shifted NPOA to my further target.  It took up about 1/3 of my front sight.  I clicked up to my 600 yd zero and fired a five round group.  I called all the shots good.  No dirt splashes.

That was a rather far target.  How far:   The target was 1/3 the width of the front post, so its range is (reciprocal of 1/3) times 250meters which is 3 times 250 meters, which is 750 meters away.  With a 600 yd zero, (let's lump yards and meters into the same bag for quick mental math purposes) the come-ups to get from 600 yds to 750m would be 6 + 4 for a total of 10 clicks.  So 600 meters/yds needed 10 more clicks to get to 750.  If you were hitting 10 clicks low at 750m that's 75 inches low. 

Unfortunately, upon checking the targets, the further silhouette had no holes.  Not even in the surrounding cardboard.  I could find no scrapes in the dirt as it is thick prairie grass.  Hmm..

The closer silhouette also had no holes..  In the dirt in front of the target were my bullet scrapes, aprox 40 inches below impact zone.  So, I had underestimate my range...  It was strange because I felt like this target was only 250 meters or so away, and I thought clicking to 300m would be overkill.  I also thought the further away silhouette was only 500m away.  Of course, this could not be the case if it took up 1/3 of my front sight, (2and2/3 moa) 

Feeling somewhat discouraged (and out of time) I packed up and considered buying a range finder.

Maybe the landscape threw me off.   It was a series of rolling hills (Iowa)... Maybe I wanted to believe that 500m was really really far off, when it didn't seem so.  Maybe my calculations are wrong.

Your feeling overruled your math.  You're learning valuable facts about your perception, your rifle and bullet trajectories at full distance. 
If you worked it from the "battlesight zero", or known set of information for your rifle sight, your particular target, and that target's size relative to your sight post, you would have been a lot closer.  Try it again with a pencil and paper, out on the range with these same targets.  Take a sight picture, establish the target to sight ratio, estimate the range, and dial it in.  You're not generating magic numbers, just the best places to start.  Keep at it. 

I like the idea of having the skill to do the job without fancy equipment.  Of only needing to have my rifle to make shots. . . But at this point, it seems too chancy. 

The estimate is only as good as your set of assumptions (sight width, target width) and judgement (target to sight ratio).  Persist.  You underestimated the ranges, maybe even overrode what the math and the sight picture were telling you.  Trust the sight picture and math, they will diligently report the facts, and then the mind can get in line. 

It seems that making estimations like "my target is 1/3 of my front sight" is very prone to mistakes.  Perhaps this can be corrected by doing more unknown distance shooting.

Most definitely, do more distance shooting, learn or test something each time.  This is the best fun.

Thoughts?

I think you should do some more of this.