A little longer range testing

[26Charlie]

Let me preface this by stating that the winter here in Maine has been wet and cold - the farm range I shoot at is a bit downhill, and the targets are at 100, 200,and 300 yards but when things are wet as they have been this spring one can get stuck even with 4-wheel drive. So I have only done some limited testing at 100 yards. I have a couple of 14x18 cabinet doors, painted white, and I thought I could use them at 300 yards - I wanted to know the sight settings to go from 100 yard point of aim to 300 yards, since the last time I did any sight changing was for CB silhouette matches 20 years ago. (I am 76 now)
First was the M1A .308 with hardball - 100 yd setting was up 8 clicks, 300 setting was up 15 clicks, an additional 7 clicks of elevation. So far, so good. I disremember how many minutes a click equals.
Second, for cast bullets I got out my .30-06 Springfield with Lyman sights, using the 220 gr. 311331 RNGC over 24 gr. 4198. I figured this will be representative of most cast bullets, in the 1650 -1750 fps range. Checked the sights at 100 with 1 shot, an X, so they were still on. Put on an additional 25 minutes and fired 3 at 300, getting 2 hits a bit low center and one very close in the dirt under which I would claim as faulty trigger squeeze on my part. I'm going to try some other CB rifle loads using this data.
I have to admit I was pleased with myself for the results of this test with iron sights.

[mac1911]

220 grain bullet @ 1750 will need 13 minutes or so to get you on from 100 to 300.

[Bohica793]

220 grain bullet @ 1750 will need 13 minutes or so to get you on from 100 to 300.

Ok Mac, you have my attention. How are you determining the additional minutes required? I'll be the first to admit that I know just enough to be dangerous and would appreciate an education and the formula for figuring this, please.

[26Charlie]

I estimated the correction from the silhouette data -13 minutes would have gotten me to 200 yards, so added more. I am reading the settings off the slide of the Lyman 48 sight. 18 minutes is dead on for 100, 43 minutes gave me the hits at 300. Front sight is a Lyman 17 with ring insert. Maybe the load is slower than I think.

[Scharfschuetze]

Looks like you're in the ball park with those sight settings.

I disremember how many minutes a click equals.

The M1 Garand and the M14/M1A rack grade sights have a 1 MOA change per click for both elevation and deflection. The NM sights have 1 MOA per click for elevation and the offset aperture in the hood gives a 1/2 MOA change. Deflection is 1/2 MOA per click.

My sight settings (depending on temp, atmosphere, light, etc.) with LC M118 match ammo or 168 SMKs for the M14/M1A are, give or take an MOA:

100 to 200 = +2
200 to 300 = +3
300 to 400 = +3
400 to 500 = +3
500 to 600 = +4

Cast bullets are often 3X or more the above settings, but can vary quite a bit depending on the bullet and velocity. Many NM shooters will file the front sight down to a zero of +2 or so at 100 yards so that when shooting at extended ranges, the rear sight is as low as possible for a good cheek weld on the stock at say 600 yards.

Those Lyman sights are the cats meow for a marksman with easily adjusted settings for different ranges or loads.

Good luck with the weather and getting to the range up there in Maine.

[mac1911]

Ok Mac, you have my attention. How are you determining the additional minutes required? I'll be the first to admit that I know just enough to be dangerous and would appreciate an education and the formula for figuring this, please.

I just plugged in your data to a ballistic calculator and gave a rough data point of 1" for sight height above the bore and a BC of .35 figure this would be "good enough for rough cal"
I,use hornady basic calculator. Or what ever comes up on a google search.

YOUR ROUND 220 GR. .35 B.C.
Range Muzzle 100 200 300
Trajectory -1 0 -13.3 -44.8
Come UP in MOA 0 0 6.4 14.3
Come UP in Mils 0 0 1.9 4.1

[Bohica793]

I just plugged in your data to a ballistic calculator and gave a rough data point of 1" for sight height above the bore and a BC of .35 figure this would be "good enough for rough cal"
I,use hornady basic calculator. Or what ever comes up on a google search.

YOUR ROUND 220 GR. .35 B.C.
Range Muzzle 100 200 300
Trajectory -1 0 -13.3 -44.8
Come UP in MOA 0 0 6.4 14.3
Come UP in Mils 0 0 1.9 4.1

Thanks for the info!

[mac1911]

I estimated the correction from the silhouette data -13 minutes would have gotten me to 200 yards, so added more. I am reading the settings off the slide of the Lyman 48 sight. 18 minutes is dead on for 100, 43 minutes gave me the hits at 300. Front sight is a Lyman 17 with ring insert. Maybe the load is slower than I think.

i would think so? your 100 yard zero is on the 18 min scale or 18 clicks up. lyman scale is in 5 minute increments correct?

your 25 minute change from 100-300 could be slower load or possible just head position on the comb?

Im new to a lot of this but have been playing with a lot of cast loads lately... mostly 165 and 200 grains in all the popular milsurps.... if your elevation from 100-300 is 25 min then i would gander your load is closer to 1200fps ? play with the balistic calculators and input different velocities....

I also use a generic BC of .35 for most of my cast bullet calculations. Im not sure what the 311311 mold your using is but from the cast bullets i use they all seem to fall between .32-.38 ? sight height should be more precise also but if your using the lyman globe sight 1-1.5" should be close enough.

im one of those guys ..... get me close and i will figure it out from there. I then use luggage tags to write the ammo and zero info on and clip it to the sling loop on the rifle.

lighting can play games with your zeros.... i need to come up 2-3 min at one range as its always very bright.

[26Charlie]

The BC for cast bullets is all over the lot, so that is the major variable in the calculator program. BC for each design is experiential. Velocity is measured at muzzle and at target, and BC calculated from that. Each design is different.
The Lyman 48 sight slide is marked in 3 minute increments, each corresponding 12 clicks. How much that moves actual point of impact depends on the rifle configuration and the load. I am going by what I have recorded in the past applied to what I wanted to do, which is to make 300 yard hits.
This has echoes of climate change modeling. Today June seventh is the first day warm and dry enough for me to plant potatoes, but if the climate does catch up to the models I have a plot where I want to put in oranges and grapefruit and maybe a lime tree.
Models are useful, but as has been said in other contexts the map is not the terrain.

[mac1911]

The BC for cast bullets is all over the lot, so that is the major variable in the calculator program. BC for each design is experiential. Velocity is measured at muzzle and at target, and BC calculated from that. Each design is different.
The Lyman 48 sight slide is marked in 3 minute increments, each corresponding 12 clicks. How much that moves actual point of impact depends on the rifle configuration and the load. I am going by what I have recorded in the past applied to what I wanted to do, which is to make 300 yard hits.
This has echoes of climate change modeling. Today June seventh is the first day warm and dry enough for me to plant potatoes, but if the climate does catch up to the models I have a plot where I want to put in oranges and grapefruit and maybe a lime tree.
Models are useful, but as has been said in other contexts the map is not the terrain.

I agree this is why i looked at the average BC that i could find in the few loading books I have.
this is also why i often say "close" or enough to get you there and dial in from there.
one thing though is a minute is a minute no matter what you do. If you need to come up 3 min to get your bullet in the bull you need to come up 3 min. Now if your rear sight is made for your rifle the "clicks" should equal X per click.
agin this is all "close" calculations. For the M1 its what .008" change in sight height to move impact 1 moa ?

now from a little i learned from looking for sights for my 1903a3 the lyman 48 is either 1/4 or 1/2 moa per click and is based around a 28" sight radius for that calculation? So if your sight radius is longer or shorter it will be different of course.
but the change is pretty small until you get into much shorter or longer sight radius....or close enough.

in the end keeping a little log of what works is key. Again I will use luggage tags and write down the load and zero i use for that rifle.
Its all fun....

this is why i say go play with a basic balistic calculator. Yes variables do change but often they are very small and for the shooting we do with cast loads or skills and for me my eyes and lighting are a larger variable than a BC of .28 vs .38 ?

[mac1911]

just for fun i did a little inputting

Your Input Variables heres a .38 BC
Ballistic Coefficient 0.38 Velocity (ft/s) 1600 Weight (grains) 200
Maximum Range (yds) 500 Interval (yds) 100 Drag Function G1
Sight Height (inches) 1.5 Shooting Angle (degrees) 0 Zero Range (yds) 100
Wind Speed (mph) 0 Wind Angle (degrees) 90 Altitude (ft) 0
Pressure (hg) 29.53 Temperature (F) 59 Humidity (%) 0.78
Ballistics Results
RANGE (YARDS) VELOCITY (FPS) ENERGY (FT.-LB.) TRAJECTORY (IN) COME UP IN MOA COME UP IN MILS WIND DRIFT (IN) WIND DRIFT IN MOA WIND DRIFT IN MILS
Muzzle 1600 1137 -1.5 0 0 0 0 0
100 1438 918 0 0 0 0 0 0
200 1295 745 -15.4 7.3 2.1 0 0 0
300 1178 616 -51.5 16.4 4.8 0 0 0
400 1087 525 -112.7 26.9 7.8 0 0 0
500 1020 462 -203.3 38.8 11.3 0 0 0

here is 28
Your Input Variables
Ballistic Coefficient 0.28 Velocity (ft/s) 1600 Weight (grains) 200
Maximum Range (yds) 500 Interval (yds) 100 Drag Function G1
Sight Height (inches) 1.5 Shooting Angle (degrees) 0 Zero Range (yds) 100
Wind Speed (mph) 0 Wind Angle (degrees) 90 Altitude (ft) 0
Pressure (hg) 29.53 Temperature (F) 59 Humidity (%) 0.78
Ballistics Results
RANGE (YARDS) VELOCITY (FPS) ENERGY (FT.-LB.) TRAJECTORY (IN) COME UP IN MOA COME UP IN MILS WIND DRIFT (IN) WIND DRIFT IN MOA WIND DRIFT IN MILS
Muzzle 1600 1137 -1.5 0 0 0 0 0
100 1384 851 0 0 0 0 0 0
200 1208 648 -16.7 8 2.3 0 0 0
300 1082 520 -57.3 18.2 5.3 0 0 0
400 995 440 -127.5 30.4 8.9 0 0 0
500 932 386 -232.8 44.4 12.9 0 0 0

there is a change of 2 minutes or so.
so the more details you have the better you can guess your calcuations. other than that its "close enough"