So whats the real deal with all this ES/SD BS

[JFrank]

Do you think that a chrono could be useful to try to duplicate velocities when you have to use a different lot of a given powder?

I usually find a load recipe that shoots the best, and then chrono, but if I am working with certain combinations, I use the chrono to watch for sudden velocity spikes or drops.

Definitely useful tool for comparing lots of powder

 

[B Nettesheim]

This is a good topic to read about, with that being said I believe the only time the es/sd numbers would matter is when they remove the targets at the match and make us shoot over a chronograph.

 

[dolek]

This is a good topic to read about, with that being said I believe the only time the es/sd numbers would matter is when they remove the targets at the match and make us shoot over a chronograph.

My thoughts exactly,you nailed it on the head.

 

[JimSC]

using a 6.5 140gn Berger VLD with a G1 BC of .6 and a 2600 - 2650 FPS muzzle velocity (50 ES for the math challanged)

at 100 it does not matter unless you are shooting groups in the zeros

with a fixed point of aim at 300 the point of impact is .7 inches lower on the target at 2600 than it would be at 2650

with a fixed point of aim at 500 the point of impact is 2.6 inches lower on the target at 2600 than it would be at 2650

with a fixed point of aim at 1000 the point of impact is 15.8 inches lower on the target at 2600 than it would be at 2650

that is basic physics, depends on target distance and your own expectations/abilities whether it matters

you can run the numbers yourself at http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi if you doubt

 

[Alexander-M]

I have also wondered many times the degree of correlation of bullet speed consistency from shot to shot, to how they group on the target. Yes, theoretically, if all other factors were equal, two bullets with the same speed should have the same or very close point of impact (POI) on the target. The keywords being “very close”, which have to be defined, and I won’t get into that so I won’t risk never getting to my point here.

I have been shooting F-Class for almost six years, so I consider myself and advanced novice. I recognize that that compared to most competitive shooters, I know very little, and that only encourages me to learn more. I do this (learning) by asking questions, observing, and collecting data.

I look closely at every target I shoot, and document everything I can so later on I can compare results. I have shot very few targets at 100 yards, a few more at 300, most at 600, and some at 1000.

I analyze my 100- and 300-yard target using the paper target themselves. For the 600-yard targets, which are the ones I shoot mostly, I have both the paper targets and the e-target screen capture displays. For the 1000-yard targets, I have only the e-target screen capture displays.

I shot this first target (seven bulls) over a week ago at 300 yards for testing various Varget loads on my 6mm-BRA. This barrel had only 23 rounds prior, and I wanted to get an idea of the speed, potential over pressure, etc. I shot these with the MagnetoSpeed chronograph attached to the barrel. I wrote down on the target the speed of each shot. I fired only three shots at bull No.2 as that was all I loaded with this charge, by mistake.

I did not have enough room to fit all seven loads on the same paper, so bull No.7 was on a different paper, adjacent to the other six bulls. Loads one through six were all at the same bullet seating depth, but different from number seven, which was the load I had been using on the previous barrel rather successfully. The old barrel, BTW, still shoots fine.

How close the speeds correlate to their POI, and the effect of their spread, I leave up to you to decide.

At 300 Yards


At 1000 Yards - One match results (20 rounds)

(The wind fooled me - I saw it coming but did not believe it. From an X for #10, a 10 for #11, and finally the lone 9 for #12.)

At 1000 yards. My results at the 2019 Indiana Regional at CIHPRS, Camp Atterbury.
Note that the Standard Deviations and Extreme Spreads had no correlation to their respective scores, as other factors (likely) had more effect.


So why bother with loading to within a kernel of powder, seating bullets to the nearest 0.001", etc.? Simple: Those are the few things (factors) that we can control. There are many others that we cannot control, such as the wind, temperature, being able to clearly see the target, for which we can only hope to make good estimates.

Alex

 

[Alexander-M]

Joe,
That load was 54.80 gr of H4831SC with 180 gr Hybrids, for 284 Win.
Even though that barrel had 1585 rounds a couple of months ago, and was still shooting very well, I decided to break in a new barrel. I think the new one likes just a tad less powder. I'll soon find out.
Thx!
Alex

 

[Old Tanker]

As the beginner here, I have a question for any/all of you. Today, using a Ruger Precision, 6.5 Creedmoor, I tested some of my first loads. Using a chronograph (yard sale find by my wife), I shot two groups of 5 at a steady pace. Load was Hornady ELD-M, 43g H 4350, seated at 2.710. The groups were .612 and .693”. However the velocities had 4 radical deviations. Six rounds ranged between 2738 ( first shot)and 2773 (7th shot). I had three rounds drop all the way to 2723 and one round jump to 2782. All charges were thrown a few grains below 43, then trickled up using an RCBS 1000. Cases were once fired, Hornady match and I used CCI BR-2 primers. What can cause those radical jumps? I did have some consistency problems with a Hornady seating die in a Lee Classic Breechlock press. Not enough thread purchase to keep the die steady. I don’t have this problem with Lee seating dies for .223 and .308. I did read that wimpy shoulder pressure can cause velocities to drop.

 

[Mad_Charlie]

Definitely useful tool for comparing lots of powder

Good to know I've been doing it right for 35 years.

 

[JimSC]

while I believe that 90% of this sport is the indian not the arrow I have never had a load with high SD/ES shoot well. Of course that is no guarantee that even with a low ES/SD you will shoot a target like Alex did above. Even at short range the low ES/SD loads consistently give the tightest groups. I have always wondered is the barrel harmonics have something to do with that

 

[Lefty Trigger]

while I believe that 90% of this sport is the indian not the arrow I have never had a load with high SD/ES shoot well. Of course that is no guarantee that even with a low ES/SD you will shoot a target like Alex did above. Even at short range the low ES/SD loads consistently give the tightest groups. I have always wondered is the barrel harmonics have something to do with that

This was my thinking exactly and why I was chasing numbers all the time and passing over loads that actually shot well but the numbers sucked. This is the exact case right now with my 22-250 shooting bug holes at 200 yards time after time but the ES numbers are in the high teens to low 20's and changing the charge weight will bring the numbers down but then the groups go to shit.

 

[Mad_Charlie]

Shoot what shoots!

 

[dkhunt14]

If a barrel is tuned to shoot 2" groups at 1000, the group at about 600 will subtend much more than 2/10th MOA vertically. Maximum ordnate happens at 55 to 60 percent of target range. That's where the two trajectories have the greatest vertical separation

Sierra's software easily plots two trajectories for a given bullet at two muzzle velocities to show that.

Does Sierra's program take barrel compensation into play? Matt

 

[dkhunt14]

using a 6.5 140gn Berger VLD with a G1 BC of .6 and a 2600 - 2650 FPS muzzle velocity (50 ES for the math challanged)

at 100 it does not matter unless you are shooting groups in the zeros

with a fixed point of aim at 300 the point of impact is .7 inches lower on the target at 2600 than it would be at 2650

with a fixed point of aim at 500 the point of impact is 2.6 inches lower on the target at 2600 than it would be at 2650

with a fixed point of aim at 1000 the point of impact is 15.8 inches lower on the target at 2600 than it would be at 2650

that is basic physics, depends on target distance and your own expectations/abilities whether it matters

you can run the numbers yourself at http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi if you doubt

I loaded up a test for my hunting gun trying to find a node and see what shot. I fired them at 1000 yards and shot them just like a match. I colored the bullets an shot them round robin. It was a 338 Lapua IMP shooting 300 grain Bergers.

The first load was 103 grains and went 2903 average.
The next load was 104 grains and averaged 2945.
The third load was 105 grains and averaged 2993.
The first load hit about 4 inches low from point of aim. The second load was right at point of aim. The third load was also right at point of aim. Seven of the last 8 went into 4.25 inches and one leaked out to make it 6.25 inches.

While there clearly was an increase of 50 feet per grain of powder, the target didn't really show it, especially with the last two which were 50 fps different. I have done this with other guns and cartridges also. I believe nodes and barrel compensation can change things. It doesn't make sense if looking at ballistic tables and numbers, but I have seen this happen many times. Matt

 

[JimSC]

It doesn't make sense if looking at ballistic tables and numbers, but I have seen this happen many times. Matt

I have no clue as to why your results came out the way they did but why do you bother handloading if you believe consistency or lack of consistency has no effect ? I thought that making consistent ammo is the entire goal of handloading, otherwise you might as well go buy white box ammo from Walmart

 

[mikeeg02]

I have no clue as to why your results came out the way they did but why do you bother handloading if you believe consistency or lack of consistency has no effect ? I thought that making consistent ammo is the entire goal of handloading, otherwise you might as well go buy white box ammo from Walmart

That's kind of a silly question to ask isn't it?

The first part of that he said that 103 grains of powder shot 2903 (40 fps slower then the next) and printed 4" lower than the latter two charges.

That's something a ballistic calculator should tell you.

Now the second part of that was that there was a 50 fps velocity difference between the second two charges. But because of barrel harmonics and some other effects, they hit the same point of impact on the target. That's something a ballistic calculator cannot tell you.

It's not about a lack of consistency. It's about finding where the barrel wants to consistently hit the same place.

Edit: the point is, there are things going on to shoot small that you cant necessarily find in chronograph results

 

[Bugs]

I have no clue as to why your results came out the way they did but why do you bother handloading if you believe consistency or lack of consistency has no effect ? I thought that making consistent ammo is the entire goal of handloading, otherwise you might as well go buy white box ammo from Walmart

Matt, how did you set all of the 1000 yard records you've set shooting Walmart ammo? ? ? If I'd only have known. . .

 

[JFrank]

That's kind of a silly question to ask isn't it?

The first part of that he said that 103 grains of powder shot 2903 (40 fps slower then the next) and printed 4" lower than the latter two charges.

That's something a ballistic calculator should tell you.

Now the second part of that was that there was a 50 fps velocity difference between the second two charges. But because of barrel harmonics and some other effects, they hit the same point of impact on the target. That's something a ballistic calculator cannot tell you.

It's not about a lack of consistency. It's about finding where the barrel wants to consistently hit the same place.

Edit: the point is, there are things going on to shoot small that you cant necessarily find in chronograph results

Well said Mike

 

[swd]

I have no clue as to why your results came out the way they did but why do you bother handloading if you believe consistency or lack of consistency has no effect ? I thought that making consistent ammo is the entire goal of handloading, otherwise you might as well go buy white box ammo from Walmart

I think you just figured out Matt’s secret to setting his 7 Benchrest world records. Give it a try. Lol.

Edit, please take this as pun intended

 

[Marksman63]

That shows that living with the single kernel of powder is useless...

 

[JimSC]

before you start flaming me Look back through my past posts, I have always stated that the person pulling the trigger more than the ammo he/she is using but threads like this confuse me. So work with me a bit, that is why I read the forum and ask questions.

Either consistent performing ammo matters or it doesn't which is it? Even though I have never set any sort of record and probably never will I will continue to go for the consistency simply becasue I enjoy the prep and reloading process and hopefully one day the wind/mirage reading might click for me. I am serious though, if you don't feel the velocity consistency matter, why do you bother? I am not trying to make anyone mad I am just curious. What matters and what doesn't, I seem to be getting mixed messages here