Long distance range and chronograph

[jay.sharkbait]

What if you're "known" distances are off by 2%? Seems to me that it might be difficult to accurately measure 500 yards.

That, or a bunch of other factors like height over bore, zero, actual b.c., etc.

If you're using advertised ballistic coefficient to calculate your velocity, your numbers are probably off a lot more than any chrono.

So, if all of those factors are off, the best solution is to add more error by using a chrono?  The goal is to limit or reduce error, not add more.

Seriously, don't take my word for it, attend a real long range shooting class, watch a dvd or read a book by someone who is a well respected expert.  You won't find them using a $100 chrono.

In my opinion, the best solution for an average hunter is to use Litz' G7 values, a laser rangefinder, reliable weather and altitude data and any of the free programs.

With as much deductive reasoning that goes on around here, you would think some people would understand a deductive algorithm.

[bobcat]

One thing to keep in mind, in this thread we're only talking about a distance "further than 200 yards." That's the question that was asked originally, so I'm not sure he needs to be concerned with G7 values, weather, altitude, chronograph inaccuracies, and deductive algorithms. It didn't sound to me like he's wanting to shoot a half mile, so I think some of you are making this a whole lot more complicated than it needs to be.

[jay.sharkbait]

One thing to keep in mind, in this thread we're only talking about a distance "further than 200 yards." That's the question that was asked originally, so I'm not sure he needs to be concerned with G7 values, weather, altitude, chronograph inaccuracies, and deductive algorithms. It didn't sound to me like he's wanting to shoot a half mile, so I think some of you are making this a whole lot more complicated than it needs to be.

I rest my case

[jasnt]

What if you're "known" distances are off by 2%? Seems to me that it might be difficult to accurately measure 500 yards.

That, or a bunch of other factors like height over bore, zero, actual b.c., etc.

If you're using advertised ballistic coefficient to calculate your velocity, your numbers are probably off a lot more than any chrono.

   Advertised bc is almost always grossly over estimated(especially nosler) another mistake made in that senecio is using g1 for boat tailed bullets. G1 is for flat based bullets and using it for g7 bullets will alter your drop charts. Not much for 500 yards or less but as you get out farther the deviation is more apparent  jme

I too use litz's bc's

Course if bobcats correct this is all just jibberish anyway.

[Biggerhammer]

 

[b23]

Course if bobcats correct this is all just jibberish anyway.

Maybe so but at least my misses will be a lot closer and don't you get something like half a point for a close mis or am I thinking of a different game...

[kentrek]

+1 on the magneto speed. They are very accurate.

 

[JDHasty]

I have a couple of Oehlers that I have had for decades.  One is a 33 and the other is a 35P and they are laboratory grade accurate.  Others...  not so much.  Tacoma Rifle & Revolver has ranges out to 600, but they are only open a few days per year past 200. 

With a couple good chronos you can capture data at the muzzle and at range from the same shot and then calculate the actual BC.  You need someone in the pit or a chrono with a printer to do this. 

[spoonman]

So I made it out to the range and shot at 100 and sighted in for 200yards. I'm shooting a model 10 Savage in 243, the round I'm shooting is a 75g horady superformance with a advertised mv of 3580. I have to say this one of the most accurate rifles I've ever shot, at 100 yds I shot 3 groups and not one of the groups was bigger than 1/2" so I'm very happy. So since I really couldn't find a range for long distance I went to the hills to a spot I remembered and ranged spots all the way out to 500 and set targets. Started at 200 and shot a beautiful group so I moved to 300 and put 3 shots in a 2.5" group, moved to 400 and once I got on target I made another pretty nice group and the Sam exact thing at 500. I got lucky with the weather and spent 2.5-3 hours getting dialed in and now have all the info I need for my rifle. So thank you guys for all your input!

[yorketransport]

Now that's right way to get data!

 I've shot with a lot of guys how've never shot over a chronograph but were leathal out to 5-600 yards just because they actually went out and shot.

[JDHasty]

Now that's right way to get data!

 I've shot with a lot of guys how've never shot over a chronograph but were leathal out to 5-600 yards just because they actually went out and shot.

They are not necessary, but we were wanting to validate the published BC and also the velocities published in reloading manuals back in the1980s and also just to entertain ourselves.  To calculate BC you do need a couple laboratory grade chronographs and also survey accurate distance between the chronograph screens.  You also needed walkie talkies or cellular phones and someone to hang out in the pit, but today a data connection is probable an affordable alternative. 

We would lace the screens on the Oehlers and shoot through to proof them and adjust screen spacing to zero them one against the other.  A magneto speed and an Oehler sounds accurate enough and far cheaper today. 

[yorketransport]

Now that's right way to get data!

 I've shot with a lot of guys how've never shot over a chronograph but were leathal out to 5-600 yards just because they actually went out and shot.

They are not necessary, but we were wanting to validate the published BC and also the velocities published in reloading manuals back in the1980s and also just to entertain ourselves.  To calculate BC you do need a couple laboratory grade chronographs and also survey accurate distance between the chronograph screens.  You also needed walkie talkies or cellular phones and someone to hang out in the pit, but today a data connection is probable an affordable alternative. 

We would lace the screens on the Oehlers and shoot through to proof them and adjust screen spacing to zero them one against the other.  A magneto speed and an Oehler sounds accurate enough and far cheaper today.

Calculating BCs isn't really that complicated. I calculated the BC of the 160gr Matrix VLD using a $100 shooting chrony set up at 10' from the muzzle and then at 100 yards. My results were within .002 of the Litz BC. Shooting just doesn't need to be that much work

[JDHasty]

Now that's right way to get data!

 I've shot with a lot of guys how've never shot over a chronograph but were leathal out to 5-600 yards just because they actually went out and shot.

They are not necessary, but we were wanting to validate the published BC and also the velocities published in reloading manuals back in the1980s and also just to entertain ourselves.  To calculate BC you do need a couple laboratory grade chronographs and also survey accurate distance between the chronograph screens.  You also needed walkie talkies or cellular phones and someone to hang out in the pit, but today a data connection is probable an affordable alternative. 

We would lace the screens on the Oehlers and shoot through to proof them and adjust screen spacing to zero them one against the other.  A magneto speed and an Oehler sounds accurate enough and far cheaper today.

Calculating BCs isn't really that complicated. I calculated the BC of the 160gr Matrix VLD using a $100 shooting chrony set up at 10' from the muzzle and then at 100 yards. My results were within .002 of the Litz BC. Shooting just doesn't need to be that much work

Of course they were, you are one of those special people who can load a batch of ammo that has velocity with standard deviation of < .002 //s//

That aside:
From Shooting Chrony's own web site:
Every SHOOTING CHRONY® measures the speed of bullets, arrows, shotgun & airgun pellets, paintballs, et cetera, from 30/fps. to 7000/fps. and with better than 99.5% accuracy.

So you are using an instrument with an error of < .005 and you need to take readings at two distances.

The precision of your results cannot, by definition, be any more precise than the least error of any of your measurements. 

[yorketransport]

Now that's right way to get data!

 I've shot with a lot of guys how've never shot over a chronograph but were leathal out to 5-600 yards just because they actually went out and shot.

They are not necessary, but we were wanting to validate the published BC and also the velocities published in reloading manuals back in the1980s and also just to entertain ourselves.  To calculate BC you do need a couple laboratory grade chronographs and also survey accurate distance between the chronograph screens.  You also needed walkie talkies or cellular phones and someone to hang out in the pit, but today a data connection is probable an affordable alternative. 

We would lace the screens on the Oehlers and shoot through to proof them and adjust screen spacing to zero them one against the other.  A magneto speed and an Oehler sounds accurate enough and far cheaper today.

Calculating BCs isn't really that complicated. I calculated the BC of the 160gr Matrix VLD using a $100 shooting chrony set up at 10' from the muzzle and then at 100 yards. My results were within .002 of the Litz BC. Shooting just doesn't need to be that much work

Of course they were, you are one of those special people who can load a batch of ammo that has velocity with standard deviation of < .002 //s//

That aside:
From Shooting Chrony's own web site:
Every SHOOTING CHRONY® measures the speed of bullets, arrows, shotgun & airgun pellets, paintballs, et cetera, from 30/fps. to 7000/fps. and with better than 99.5% accuracy.

So you are using an instrument with an error of < .005 and you need to take readings at two distances.

The precision of your results cannot, by definition, be any more precise than the least error of any of your measurements.

FWIW, the 99.5% accuracy is the average tolerance of their equipment. That doesn't mean every machine that comes off of the line is 99.5% accurate 100% of the time. My $100 chrony was just as consistent and as accurate as the Oehler 35P that I had before it. I sold the Oehler after buying the Shooting chrony because my results were so close between the 2 and the Oehler was such a pain to set up. I paid $250 for the 35P and sold it for $550 to some sucker just after they stopped producing them. I've never missed it. Even now I have a Magneto Speed and still use the beat up Shooting Chrony as well.

I've said it before and I'll say it again, shooting at any distance just isn't that tough. Handloading and getting accurate loads just isn't that tough. Getting single digit ES and SD velocities just isn't that tough. Shooting .25 MOA 3 shot groups at 100 yards isn't that tough. It doesn't require any technical back ground, special equipment, or shooter's voodoo. It just takes time, patience, and practice. Look how often people post on here showing sub .5 MOA groups with inexpensive guns shooting factory ammo. Equipment is getting so good these days that even affordable guns, ammo, optics and chronys will get you consistent and reliable results just as good as high dollar items.

[spoonman]

Once again thank you guys for the advice! I am a bow hunter at heart but have found a new love of picking off yotes at a longer distance. I was shooting my 338 before I got this rifle and needless to say the coyotes didn't do too well against a 210 grain round! I don't load my own rounds so I have settle on the 75 grain horndy superformance witch has a listed mv of 3580 but out of my rifle (24" barrel) its at the 3550-3560 mark, not a huge difference but it's enough.