Confused about long range load development discussions

[Mystic Precision]

A very good F Open shooter and I were discussing the trend to velocity tuning. I said, bad idea... he thought, good idea. He created his own test using a superbly accurate rifle, all the steps to prepare and shoot the groups under calm conditions. Took great notes and voila, this is the data that he created.

There is a ton of info in this chart if you take the time and study it.... and it confirms what I, and many others in the LR precision game know, velocity testing can provide false positives.

ES and SD's do not tell you what will happen on target

Shoot on paper at distance. Targets don't lie. If you have 2 loads near identical, use the one with the best data... however, after almost 15yrs of launching lead way out there, I have yet to see a tie between 2 loads when tested at distance.

Accurate loads will almost always show good numbers..... good numbers in a load, does not always mean it is accurate.

Jerry

 

[Ryan.M.Anderson]

Just to play devils advocate here Jerry, doesn't load "D" show a pretty killer group? I know your retort will be load "A" also shows wicked numbers and is a bad group. Just giving you the gears of course.

I do agree that paper doesn't lie but some of us need short cuts due to time constraints, range limitations, etc. and this is why I do the 100Y/M development with a Chrono.

When I was doing my 6.5X47 development I had one load that looked great on the Chrony (ES of 4 and SD of 1 or something like that) but it was shooting 1"+. I had another load that had slightly worse numbers (ES of 11 and SD of 4 or something like that) but was grouping in the .4s.

It would be interesting to know what the groups looked like at 100.

 

[JEC]

I would respectfully disagree with the statement that a bullet is either stable or not as that is this is not what has been found. The design of bullets is a huge issue and at certain ranges the bullets can destabilize and this has been known for a long, long time. For example, the 168 grain Sierra Matchking was designed to win at 300 meters and it does a great job within that range parameter but it is so unstable at longer ranges that many ranges have banned them for 1000 yard competitions due to the danger to the target pullers.

The latest generation of high BC bullets are proving to be very hard to keep stable at longer ranges but now the marketplace has been conditioned to accept that only high BC bullets are the "best" thing to consider.

The idea that a bullet is accurate at all ranges has not been proven to be a fact.

Physics says that a bullet that is stable as it leaves the muzzle, maintains that stability for the duration of its trajectory ....essentially because the speed is shed faster than the rate of spin. Conversely, a bullet that is unstable as it exits the muzzle, will not become stable (“pitch” and “yaw” does not induce gyroscopic stability).

 

[kthomas]

View attachment 184093

A very good F Open shooter and I were discussing the trend to velocity tuning. I said, bad idea... he thought, good idea. He created his own test using a superbly accurate rifle, all the steps to prepare and shoot the groups under calm conditions. Took great notes and voila, this is the data that he created.

There is a ton of info in this chart if you take the time and study it.... and it confirms what I, and many others in the LR precision game know, velocity testing can provide false positives.

ES and SD's do not tell you what will happen on target

Shoot on paper at distance. Targets don't lie. If you have 2 loads near identical, use the one with the best data... however, after almost 15yrs of launching lead way out there, I have yet to see a tie between 2 loads when tested at distance.

Accurate loads will almost always show good numbers..... good numbers in a load, does not always mean it is accurate.

Jerry

I'm going to come out of hibernation briefly to retort, then I'll go back to my hidey hole.

This is one of the differences between bench rest shooters and practical/field shooters.

Bench rest shooters tune their load for a certain distance. Say for example 1,000 yards. To get the absolute most precision at a set distance, the load with the best ES/SD may not be the most precise. That comes down to barrel harmonics and that sort of sh*t. Works great if you are shooting at one set distance.

Field/practical shooters have to develop a load that works good from 100 yards to a mile or more. That's why we find velocity nodes per the "Scott Satterlee method". We need our loads to work throughout a wide range of distances, so we need to develop a load doesn't have large variations in velocity. It works and it creates very predictable results. Myself and many others have used it to great success. May not shoot world record bench rest groups, but you can make some very precise ammo (~1/4 moa or so).

As Ryan points out, load "D" looks pretty good from a velocity node standpoint. When I try to find my velocity node, I load up two rounds each of each powder charge (0.2 grain increments), and shoot two ladders. The results are usually predicable and repeatable.

So if you want a load that provides the maximum precision at a set distance, tune your load to that specific distance. If you want it to work throughout a wide range of distances, you may want to find your velocity node.

Okay, back in my hidey-hole.

 

[Mystic Precision]

Just to play devils advocate here Jerry, doesn't load "D" show a pretty killer group? I know your retort will be load "A" also shows wicked numbers and is a bad group. Just giving you the gears of course.

I do agree that paper doesn't lie but some of us need short cuts due to time constraints, range limitations, etc. and this is why I do the 100Y/M development with a Chrono.

When I was doing my 6.5X47 development I had one load that looked great on the Chrony (ES of 4 and SD of 1 or something like that) but it was shooting 1"+. I had another load that had slightly worse numbers (ES of 11 and SD of 4 or something like that) but was grouping in the .4s.

It would be interesting to know what the groups looked like at 100.

Ryan, you understood the point... both groups A and D show extremely nice numbers and if you tuned by velocity, you would likely choose A which I am guessing will shoot extremely tight at 100yds vs the load D.

And there in lies the problem with velocity tuning and short range groups, it doesn't always tell you the truth. When I am load tuning, I don't want to use a method that can provide more then 1 answer.... that seems counter productive to me.

But use whatever method works best for you... if you have confidence in the result, that is what matters.

For those that don't understand, F class is shot at multiple distances from 300m to 900m. We do not have time to load between relays and I don't know of anyone that loads overnight. You shoot the ammo you loaded at home and brought to the match... often in another province

If you participate in the Provincial or National match, you will shoot multiple distances in one day and which distances you shoot will vary over the 3 day match. Accurate drops matter as hitting center with the sighters goes a long ways to improve chances of a better score.

The V bull is typically 1/2 MOA circle, the 5 ring is MOA, 4 ring is 2 MOA... you want to hit that 5 ring as often as possible with as many V's as possible in case of a tie.

Jerry

 

[shockman]

And after hours and hours and hundred's of $$ you find the LOAD !! BUT the method I like the most is when I just throw some shat together, go to the range and shoot short and long and go "WOW" that load works LOL

 

[Ganderite]

Physics is physics ... a bullet that is “off course” @ 100Yd does not steer back to the centerline (by any appreciable amount) with distance. The term “appreciable” refers to the cyclonic swirl effect, sometimes referred to as “augering” which (if my recall is correct) can be up to .05” in a hundred yards. If the bullet is off course by an inch at 100yds and still “wobbling” a bit ... and “stabilizes” ... thereafter.... that stability does not steer it back towards the centerline.
Anyone arguing that their particular rifle “steers” them straight needs to explain why the same does not happen with every same/twisted/velocity bullet exiting another firearm.

Yes it does. In the vertical plane. A 1 inch group (vertical) at 100 might still only be 1" at 200. Or it might be 3" (not 2").

Some rounds are faster than others. The fast ones will tend to print high and the slow ones to print low. Bot the muzzle is whipping up and down. If it is moving up when the bullets exit, the slower ones will be aimed a bit higher, so they will print less low than otherwise.

This is why some loads are really good and some are really bad - in a given rifle. And why 100 results don't mean much at long range.

This has nothing to do with stability or wobble.

 

[JEC]

Yes it does. In the vertical plane. A 1 inch group (vertical) at 100 might still only be 1" at 200. Or it might be 3" (not 2").

Some rounds are faster than others. The fast ones will tend to print high and the slow ones to print low. Bot the muzzle is whipping up and down. If it is moving up when the bullets exit, the slower ones will be aimed a bit higher, so they will print less low than otherwise.
This is why some loads are really good and some are really bad - in a given rifle. And why 100 results don't mean much at long range.
This has nothing to do with stability or wobble.

In order to “group” each bullet must exit the crown with the “whip” in the same position...100yd 1” groups don’t hold to 1” at 200. Shoot through a paper at 100 and let us know how they look at 200. The stability I speak of was referencing an earlier statement about a bullet “settling down”.

 

[Maple57]

One more thought on this thing relating to barrel twist rate and muzzle velocity...

Heavier bullets require a faster twist rate per given velocity, but higher velocity can get by with a slower twist rate.

Best accuracy is always with the slowest possible twist rate that wil adequately stablize the bullet.

So... when you use a bullet and barrel twist rate that pushes the envelope of slightly too slow, the spin rate is actually getting better as the bullet flies down range and eventually forward movement will slow to the point where the bullet is at the ideal spin rate. This is because the spin rate does not slow down as fast as the forward speed of the bullet.

A bullet fired at 3000 fps from a 1:10 twist barrel will be spinning 1:5 when the velocity drops to 1500 FPS, so basically the gyroscopic stability factor is increasing constantly as the bullet travels downrange.

Those of us who find loads that are not as good at 100 yards as 300 yards, may just be running slightly too slow barrel twist rates or slightly not fast enough velocities.

 

[kthomas]

I was reading a thread on accurateshooter.com about "positive compensation", and it reminded me of this thread.

It's a good (and short) thread, which discusses the concept of "positive compensation". Essentially, any time you perform load development at a set distance (whatever it may be), with different charges and looking for the smallest group/lowest vertical, you are performing in essence a form of positive compensation. As Alex Wheeler puts it "The whole idea is to find the tune where bullets of different speeds cross paths at the intended distance. That can only happen at one distance. But the tune will still shoot well at other ranges because its still in tune."

It's a different way of going about things. Rather than worry about consistent velocities (low ES), you find a node in which your barrel releases the bullet at the same attitude of this "barrel whip", inconsequentially of the bullets velocity. So if the bullet is going 50 fps faster or slower than the previous bullet, it still leaves the barrel at the same point in its "barrel whip" path. In this method, ES is much less of a factor, as you are trying to mitigate the effects of high ES.

If you do decide to perform a sort of "positive compensation", it's much better to perform at a longer distance than a shorter distance, per Alex Wheeler. The thread can be found here for those that are interested: http://forum.accurateshooter.com/threads/positive-compensation.3954612/

If you do plan on shooting to great distances, say a mile and beyond, having a low ES will help over having a load tuned for 200 or 1,000 yards. The farther you shoot, the more important it is to have low ES. At the end of the day, we still have to deal with the laws of physics. If you shoot at known distance square ranges the vast majority of the time, then the positive compensation method can be used very successfully. If you shoot in the field at lots of distances, spread out from 100 to a mile and beyond, ES will be much more important of a factor. There are reasons why bench rest shooters predominately employ some form of positive compensation, while ELR/PRS/NRL/etc. predominately employ a method that finds a velocity node, like the "Scott Satterlee method".

 

[Astute Observer]

• Small groups at 100m, small groups at 500m: All's good, don't change anything.
• Small groups at 100m, vertical dispersion at 500m: Your velocity has too much variance. Work on your loads to get your SD and ES down.
• Small groups at 100m, horizontal dispersion at 500m: Learn to read the wind better.

I have had loads that shot 0.5 MOA (my personal shooting limit, I couldn't shoot any better even with a laser gun on a tripod) at 100m, but had a wide ES and SD. The barrel liked the harmonics, the internal ballistics were great.

I also had loads that I shot 0.9 MOA but had really low ES and SD.

That 0.4 MOA difference = 2" difference at 500m, and 4" difference at 1000m. To me, that's not a big deal at all.

But a 40+ fps variance in velocity (SD) would translate into a much greater difference than 4 inches at 1000m... Like we're talking measuring the variance in impact point in feet, not inches.

To me the choice is clear. Once you're within 1 MOA, stop chasing accuracy and start chasing consistent velocity.

 

[manitou210]

DO NOT FORGET YOUR LOAD AT 100 Y WHEN VELOCITY IS TOUCHING MAX SPEED AND SHOOTS .250" OR SMALLER.
MY FRIENDS .308 WIN 30" FTR DOES JUST THAT HE TOOK LOAD OUT TO 900M IN A 2 SIGHTER & 15 SHOTS RELAY 11 V BULLS AND 4 BULLS
SO MUCH FOR NOT SHOOTING GOOD GROUPS AT 100 Y, IT MATTERS LOTS.
HE ALSO SHOT THE MOST v BULLS AT WORLDS F CLASS IN OTTAWA LAST YEAR

 

[kthomas]

DO NOT FORGET YOUR LOAD AT 100 Y WHEN VELOCITY IS TOUCHING MAX SPEED AND SHOOTS .250" OR SMALLER.
MY FRIENDS .308 WIN 30" FTR DOES JUST THAT HE TOOK LOAD OUT TO 900M IN A 2 SIGHTER & 15 SHOTS RELAY 11 V BULLS AND 4 BULLS
SO MUCH FOR NOT SHOOTING GOOD GROUPS AT 100 Y, IT MATTERS LOTS.
HE ALSO SHOT THE MOST v BULLS AT WORLDS F CLASS IN OTTAWA LAST YEAR

I agree. Load development at 100 yards works great.

I do load development after 100 rounds have traveled down the barrel. I will perform a seating test within that 100 rounds - since I use Berger Hybrids, this is fairly easy as they shoot great from 0.010"-0.020" off the lands. After that, I use x2 fired (or more, not virgin) brass, and load up rounds in 0.2 grain increments, and test to find a velocity node.

If done right, your rifle will shoot 5 round groups like this at 100 yards, and have an ES of 15-20 (or perhaps less):

https://flic.kr/p/25BLNTL

Edit: Can't get a picture to post from Flickr. Enoch needs to quit being cheap and update this outdated forum.

 

[Mystic Precision]

DO NOT FORGET YOUR LOAD AT 100 Y WHEN VELOCITY IS TOUCHING MAX SPEED AND SHOOTS .250" OR SMALLER.
MY FRIENDS .308 WIN 30" FTR DOES JUST THAT HE TOOK LOAD OUT TO 900M IN A 2 SIGHTER & 15 SHOTS RELAY 11 V BULLS AND 4 BULLS
SO MUCH FOR NOT SHOOTING GOOD GROUPS AT 100 Y, IT MATTERS LOTS.
HE ALSO SHOT THE MOST v BULLS AT WORLDS F CLASS IN OTTAWA LAST YEAR

Never said testing at 100yds could not produce good results at further distances... I have said that it is not always correct and I choose to use a system that gives me one useable answer.

False positives don't always help....

A FTR 308 load has a well defined tune with popular bullets... so working in the known node/loads can and will provide positive results. Results may be a bit different if working with an unknown cartridge and set up....

But if it works for you and you trust it, go for it... many ways to get to the same result.

Jerry

 

[manitou210]

I agree. Load development at 100 yards works great.

I do load development after 100 rounds have traveled down the barrel. I will perform a seating test within that 100 rounds - since I use Berger Hybrids, this is fairly easy as they shoot great from 0.010"-0.020" off the lands. After that, I use x2 fired (or more, not virgin) brass, and load up rounds in 0.2 grain increments, and test to find a velocity node.

If done right, your rifle will shoot 5 round groups like this at 100 yards, and have an ES of 15-20 (or perhaps less):

https://flic.kr/p/25BLNTL

Edit: Can't get a picture to post from Flickr. Enoch needs to quit being cheap and update this outdated forum.

Kthomas that's a benchrest group you fire nice shooting Just a little advise about getting ES lower maybe single digits it will help a 900 m
If your using CCI Benchrest primers save them for your coyote hunting they don't cut it for low ES you can weigh them and separate in batches and there okay. The best primers in my observations are hands down Fed Gold match my ES runs 5 to 6 for 5 shots.
When weighing CCI BR4 benchrest they weighed 3.68 gn to 3.80 Took 5 loades 3.68 and 5 at 3.80 the spread was 49fps
I don,t have to tell you what happens at 900 m puts you out of bull that's why you can't get low ES using out of the box CCI primers
Note numbers on left are Lab Radar Silver Mountain are on target at 900 m not quite as accurate as Lab Radar


Primer Testing. in Barnard S ,Barrel 30" 1/7 T,5R Broughton,Robertson Comp Stock. NF Benchrest 12x to 42x 80.5 Bergers and 90gr Match. April 22/2017

Random pick
from box
LAB RADAR Silver Mountain
CCI BR4
2911 1191
2914 1191
2917 1203
2927 1227
2905 1194
CCI 450 Mag
2914 1189
2909 1189
2922 1158
2908 1206
2912 1193
Federal GM
2907 1213
2903 1202
2906 1198
2908 1203
2906 1191
CCI BR4
2915 1191
WT:368gn 2906 1176
2920 1202
2896 1145
2908 1194 average 2909 fps

CCI BR4
2945 1199
WT:380 2951 1197
2924 1197
2947 1222
2935 1203 average 2940 fps

 

[kthomas]

I've heard good things about FGM primers. Unfortunately they are as rare as hens teeth down here.

Honestly for what I do, 15-20 fps works just fine. I'm not shooting any bench rest matches, so I don't need quite that degree of precision. I'm more focused on field type shooting. *Edit - I should also add that the 15-20 fps ES is over ~20-30 shots on a chrono.

Those are some really impressive numbers you are getting with the FGM's though.

 

[Bile]

...

 

[Mystic Precision]

Kthomas that's a benchrest group you fire nice shooting Just a little advise about getting ES lower maybe single digits it will help a 900 m
If your using CCI Benchrest primers save them for your coyote hunting they don't cut it for low ES you can weigh them and separate in batches and there okay. The best primers in my observations are hands down Fed Gold match my ES runs 5 to 6 for 5 shots.
When weighing CCI BR4 benchrest they weighed 3.68 gn to 3.80 Took 5 loades 3.68 and 5 at 3.80 the spread was 49fps
I don,t have to tell you what happens at 900 m puts you out of bull that's why you can't get low ES using out of the box CCI primers
Note numbers on left are Lab Radar Silver Mountain are on target at 900 m not quite as accurate as Lab Radar


Primer Testing. in Barnard S ,Barrel 30" 1/7 T,5R Broughton,Robertson Comp Stock. NF Benchrest 12x to 42x 80.5 Bergers and 90gr Match. April 22/2017

Random pick
from box
LAB RADAR Silver Mountain
CCI BR4
2911 1191
2914 1191
2917 1203
2927 1227
2905 1194
CCI 450 Mag
2914 1189
2909 1189
2922 1158
2908 1206
2912 1193
Federal GM
2907 1213
2903 1202
2906 1198
2908 1203
2906 1191
CCI BR4
2915 1191
WT:368gn 2906 1176
2920 1202
2896 1145
2908 1194 average 2909 fps

CCI BR4
2945 1199
WT:380 2951 1197
2924 1197
2947 1222
2935 1203 average 2940 fps

What did the plots of each group look like?

Scores if winds were light?

What is the error range of the Silver Mountain? What is the +/- fps error inherent in the machine?

Jerry