Elevation change for 1000 yards

[ELFEGO BACA]

I have my 45/70 Pedersoli sharps with 32 " barrel. What is the approximate site adjustment for 1000 yards.

[NickSS]

From a 200 yard setting go up 120 minutes of elevation With a 500 gr bullet going around 1080 fps will get you on paper.

[Don McDowell]

Assuming you're launching a 500+ gr bullet at 1150 fps or more. 1.95 would be a good place to start.If you have a taller front sight, might want to start a 2.10
Or if you've got a 500 yd zero, come up about 17 minutes for every 100 past that 500.

[Tom Myers]

I have my 45/70 Pedersoli sharps with 32 " barrel. What is the approximate site adjustment for 1000 yards.

The required sight elevation for a stable bullet will basically depend on the Muzzle Velocity and the Ballistic Coefficient of the bullet.

If you are using a Lyman 457102 with an approximate BC of 0.350 at a muzzle velocity of 1150 fps then your sight settings might look something like this:

The charts below reflect a sight radius of 36 inches. This means that a 1 point sight change will result in a 10 inch change at 1000 yards or 0.9549 Minutes of Angle.

A Sight Radius of 34.4 inches would make changes of 1 minute of angle for each point change or 10.5 inches at 1000 yards.

http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/457121-Sights.jpg


A Paul Jones Money Bullet with an approximate BC 0.497 and seated well into a throated chamber with generous powder capacity generating a muzzle velocity of 1250 fps could require sight settings something like this:

http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/PJ-458-530MB-Sights.jpg

From these estimates, it can be observed that the importance of knowing the ballistic characteristics of a load is important to an approximation of initial long range sight settings.

Remember it is important for each load to have a verified close range (200 yards or so) setting to compare to. Two different loads might have similar trajectories but the initial recoil impulse could alter the close range sight setting considerably which would then alter the long range setting.

If you could provide some more information as to bullet type and muzzle velocity, a closeer estimate could be made of your initial long range sight settings.

Hope this helps.

[montana_charlie]

I have my 45/70 Pedersoli sharps with 32 " barrel. What is the approximate site adjustment for 1000 yards.
You didn't say what type of sights you have on the rifle.
An answer that works for the Lawrence barrel sight would be very different from the estimated settings for a vernier tang sight.

Assuming yours is a vernier tang sight, what is the setting you use for 100 yards?
Have you found a good setting for 200 yards?

If you have those two, the rest can be estimated with 'fair' precision.

CM

[RMulhern]

Start at 100 and zero all the way back!!

Simple!!

[405]

Whew, really hard to predict! The key variables would include: sight radius, height of front sight above bore center, BC/weight of bullet, velocity and stability of bullet during its flight. The incline of the bullet path starts to get really severe at the terminal end so any minor variation or error can have great affect on POI. You might play around with one of the ballistics calculators. For variables like exact BC of the bullet you might have to take a best guess stab at it. The other thing after running the numbers is to use a very large target backer and/or shoot in an area that has a lot of bare, dry ground around the target so bullet impacts can be seen and judged. I use this calculator when trying to get close at longer ranges.
http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.0.cgi

[RMulhern]

You can run and 'crunch' all the numbers one wishes....but in the final analysis....due to the way rifles are held by various shooters, by varying types/profiles/harmonics of barrels.....the sure-fire method of starting at 100 or 200 yards and working back.....is the MOST RELIABLE METHOD!!

[Don McDowell]

Rick you're right, but the op asked for sight settings at a 1000. I gave him a couple right out of my range book. Should get him close anyways.:bigsmyl2:
But you're right , the number crunching won't take into consideration any wind , light , or mirage, nor elevation difference between the target and the firing line.
And from trying to dope sight settings from programs, anything under a 500 yd setting to start with is most of the time just a WAG at 1000. Best to have a good spotter and plenty of practice ammo.[smilie=l:

[hydraulic]

Best to have a good spotter and plenty of practice ammo.

Don: I'm bringing 250 rds to Alliance. CM

[Don McDowell]

Hydraulic that's probably not a bad idea. I never go with less than 150 per rifle, and a couple of times it's been a squeeker having enough to shoot for score.
30 days and counting.

[wonderwolf]

Rick you're right, but the op asked for sight settings at a 1000. I gave him a couple right out of my range book. Should get him close anyways.:bigsmyl2:
But you're right , the number crunching won't take into consideration any wind , light , or mirage, nor elevation difference between the target and the firing line.
And from trying to dope sight settings from programs, anything under a 500 yd setting to start with is most of the time just a WAG at 1000. Best to have a good spotter and plenty of practice ammo.[smilie=l:

I was thinking about this the other day....about just how far out my tall soule sight could take me. I've got a shorter front sight that I've trimmed down as far as it will go and still allow sight picture when the rear is all the way at the top on the sharps.

Though wouldn't it be possible to collect enough data from your load and get a good average from what several programs say the drop at 1,000 should be. Go find a open flat space with a tree or wall say 100 yards distance from muzzle to wall/tree. Mark where your bore center/height is. Look through the sights at what your 100 yard zero is (a helper and a laser pointer would probably help in this) and then factor in the bullet drop and have that measured on the tree/wall and dial your rifle from bore sighting to that point?????? seems like it would work to me? at least it would be a starting point if nothing else.

[405]

:hijack:
Elfego Baca,
What in the world is "Elfego Baca" doing up in Idaho Territory? I'm a little familiar with the lawman. An older, retired US Marshal was a family friend when I was young. He had several dealings with and interesting stories about Elfego back in the day. :)

[Don McDowell]

I Go find a open flat space with a tree or wall say 100 yards distance from muzzle to wall/tree. Mark where your bore center/height is. Look through the sights at what your 100 yard zero is (a helper and a laser pointer would probably help in this) and then factor in the bullet drop and have that measured on the tree/wall and dial your rifle from bore sighting to that point?????? seems like it would work to me? at least it would be a starting point if nothing else.

Lazer pointers emit a flat lined light, not an arching trajectory as with a bullet. So no bore sighting really doesn't work. Not even with smokeless and 3x9 scopes.

You can get some general idea from the various "programs" around, but the only way to know for sure is go do it, and keep good notes, because it can change 10 minutes from one day to the next, and altituder and humidity raise a lot of cain with bpcr ballistics that isn't that noticeable with smokeless highpower stuff.
That's why most folks try and get to a match a day or two ahead of time with an extra bucket full of ammo, so they can get "sight settings" before the match starts. If you shoot at the same matches, then from year to year therer may not be a lot of difference but over time you'll likely find you'll have two or three different settings for the same target. This is where your notes come in. You can start with the settings you jotted down for the conditions nearest what you're experiencing at the moment.
And there are some places, like the range at Alliance or Kenny W's creedmoor in the 115 degree heat that a target might jump as much as 5 minutes or more during a relay.
The half mile Buffalo at Ekalaka is a prime example of jumping. The last couple of years the conditions have been some screwy crosswinds, with heavy clouds blowing thru. So one shot you might be in dark almost rain 5 minutes later you've got full bright sun coming over your left shoulder. So then you need to decide whether to chase it with your settings or hope to shade the target with the front sight.
My hats's continually tipped to folks like Kenny,Kurt, Bryan, Harlan, Jimbo and the list goes on of shooters who while they may not always bring home the bacon, they're in the running, unless something goes horribly wrong with equipment or such.
"programs" and other short cuts, can be helpful, but theyr'e not a substitute for actual trigger time.

[wonderwolf]

Lazer pointers emit a flat lined light, not an arching trajectory as with a bullet. So no bore sighting really doesn't work. Not even with smokeless and 3x9 scopes.


the laser would be to you spot the bullet drop point on your wall or whatever. I'm thinking along the lines of the sight in targets for M1 garand rifles http://www.nationaltarget.com/cgi-bin/miva?Merchant2/merchant.mv+Screen=PROD&Store_Code=NT&Product_Code=ST-1++%28priced+per+25%29&Category_Code=SST

You can get lasers to arch just not in the context your talking about [smilie=1:.

[montana_charlie]

I'm wondering if ELFEGO plans to come back and say anything more.

While we're killing time...
If anybody is wanting a used Pedersoli Sharps, Kelley Roos has one listed in the classifieds at bpcr.net.
It's the silhouette model with a shotgun butt in 45/70.
Seems like he'll consider offers...
CM

[juanvaldez]

The required sight elevation for a stable bullet will basically depend on the Muzzle Velocity and the Ballistic Coefficient of the bullet.

If you are using a Lyman 457102 with an approximate BC of 0.350 at a muzzle velocity of 1150 fps then your sight settings might look something like this:

The charts below reflect a sight radius of 36 inches. This means that a 1 point sight change will result in a 10 inch change at 1000 yards or 0.9549 Minutes of Angle.

A Sight Radius of 34.4 inches would make changes of 1 minute of angle for each point change or 10.5 inches at 1000 yards.

http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/457121-Sights.jpg


A Paul Jones Money Bullet with an approximate BC 0.497 and seated well into a throated chamber with generous powder capacity generating a muzzle velocity of 1250 fps could require sight settings something like this:

http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/PJ-458-530MB-Sights.jpg

From these estimates, it can be observed that the importance of knowing the ballistic characteristics of a load is important to an approximation of initial long range sight settings.

Remember it is important for each load to have a verified close range (200 yards or so) setting to compare to. Two different loads might have similar trajectories but the initial recoil impulse could alter the close range sight setting considerably which would then alter the long range setting.

If you could provide some more information as to bullet type and muzzle velocity, a closeer estimate could be made of your initial long range sight settings.

Hope this helps.


This is the info I am looking for as well. Here is my info:

Rifle: Pedersoli RB 30" bbl
Load: 63.3 grains 2F @ 1100FPS
Bullet: Brooks 540 Grain Pointed
Alloy: 20:1

Know Settings:
Yards Points
100 124
200 140
300 158
460 185
500 194
600 ???
700 ???
800 ???
900 ???
1000 ???

It appears I may be too slow to stay stable to 1000yards?? This from a poster on another forum.

[Tom Myers]

JuanValdez,

I assumed a sight radius of 34" and then plugged in various Ballistic Coefficients until the best match to your various sight settings out to 500 yards was calculated. The average BC that worked best was 0.3335. If your bullet stays stable on out to 1000 yards, the estimated settings should be quite close to actuals. (Although at long range, settings can change a lot from day to day)

As for the ability of your bullet to stay stable out to 1000 yards, you can only try it and see. You might consider that since you are starting the bullet out under Mach I there will be no transition through Mach I and the buffeting caused by the transition that can upset a previously stable bullet.

Acquiring and learning how to use good Ballistics Calculation Software does not guarantee to make one a good shot but it can certainly be used to help understand what is happening downrange and that knowledge can then be used to help eliminate some of the variables in the process.

Hope this helps.

http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/1100fps-3335BC-Sight-settings.gif


http://www.tmtpages.com/LinkSkyImages/forum_images/Sight%20Comeups/1100fps-3335BC-Wind.gif

This is the info I am looking for as well. Here is my info:

Rifle: Pedersoli RB 30" bbl
Load: 63.3 grains 2F @ 1100FPS
Bullet: Brooks 540 Grain Pointed
Alloy: 20:1

Know Settings:
Yards Points
100 124
200 140
300 158
460 185
500 194
600 ???
700 ???
800 ???
900 ???
1000 ???

It appears I may be too slow to stay stable to 1000yards?? This from a poster on another forum.

[Don McDowell]

That 540 gr bullet will drop in velocity to a bit over 850 fps at the 500 yd line, by the time it hits the 700 yd line its dropping below 800 fps and at that velocity , it's right on the edge of rotational speed to stay stable.
I don't think that unless you're running something like the MVA "wasserburger mile" sight you'll have enough adjustment to get that bullet to 1000 yds at that velocity. Jump the charge up and get it to at least 1150 with 1200 preferred , and you'll stand a much better chance of getting a bullet to the 1000 yd line somewhere in the vicinity of the target.

[Don McDowell]

Just got back from the Wasserburger Creedmoor, and have something for the sight settings food for thought. It took 25 minutes elevation to go from 800-900 yds, yet from 900-1000 it only took 15.. Just a bit more information to think about.

[Lead pot]

Don.

10 MOA less from 900-1000 than 25 MOA from 800-900 sounds like a wind change ane light change combined ????

I have a 18-19 MOA between 800-900 and 900-1000

[Tom Myers]

I would be inclined to think that the range distance of the targets would have that effect on your sight setting.

An arbitrary Muzzle Velocity of 1315 fps and BC of 0.438 would give those setting if the Ranges were 800, 927 and 1000 yards.

Various other combinations of MV, BC and Ranges could give the same variation in come ups but, in my estimation, the principal cause is most likely that the known ranges are not exact. It wouldn't necessarily be that just one range that is off. Different combinations of each range being off just a small amount along with round off errors on recorded sight settings could account for the anomaly.

[Don McDowell]

Kurt well maybe partially, but that's about the same that Dick had on his 50 in the morning before the match started.

Tom , no it actually happens quite a bit in the real world on the firing line. Unfortunately these big ol fat bullets trotting along at their sedate speeds don' always behave , matter of fact seldom do, the way the ones in the vacuum of a computer program do. It's not at all uncommon for an entire squad on the line to be shooting bullseyes, and all of a sudden everybody's bullets start sailing right over the top of the target frame.

[Lead pot]

I have seen times that I had to add or take off 5-6 points at the 900 or 1000 with in a hour after having a sight setting at Alliance and some times before you get 8 shots off.
Temperature , light, and wind changes keep you on your toes.

[Don McDowell]

Aw man that Switch Saturday on the 1000 at Kenny's really buggered some scores. We had found it, then all of a sudden everybody right down the line went over, I got smart and dropped, but did a little much. Doc said I hit a clump of sagebrush at the base of the target and lumber/firewood and chunks fell for 5 minutes after that..... We chuckled all the way home.
Due to the wind and light Kenny was setting behind the 900 yd berm calling back hits misses etc. He hollered something on the radio about way low,@#$$%^&* you ought to see the stuff flying...