Es & sd

Lee Martin said:
I only shoot short range, so I can't speak to ES and SD as they pertain to 600 or 1,000 yard competition. I realize they're more important at those distances. But out to 300 yards, this is what I've found...

I took my FX-120i scale and Lab Radar and checked ES's and SD's when weighed to the nearest 0.02 gr versus thrown with my Culver. I did this with LT-32 in my 6 PPC and LT-30 in my .30 Stingray. Both throw easy. I could keep them within a +/- 0.1 gr window with the Culver. No surprise, those weighed to 0.02 grs had lower ES's and SD's. The thrown charges were a higher. I'll have to dig out my notes for actual figures on this.....it's been a few years. Numbers aside, all I care about is the tale of the paper.

After many trips to the range, group size wasn't strongly correlated to ES or SD. For example, I remember shooting a two groups back-to-back under 0.150" at 100 yards (5-shots). They were weighed but showed a fairly wide spread.....like 20 - 25 fps. Another weighed charge, but a different load, showed much tighter spread but the groups opened to around 0.250" (or higher). Same day, same conditions, pretty much same everything except the ES changed. On the flip side, I had some loads that printed better with low SD's and ES's. Others, not so much.

My take on all this? You can chase low ES's and SD's and have the tightest spread be at the mid-deflection point. Conversely, you could have slightly higher ES's and SD's and be top dead center of a wide node. We want the latter.

Wide nodes and being able to center on those nodes through load tuning or a tuner is key. Powders with wide node profiles also help. All of my guns wear tuners. I want a load that'll give me a little buffer on each side of my tuner setting. So I tune exclusively to the paper. My Lab Radar rarely sees the light of day. And as mentioned before, all of this goes out the window when the flags shift. My personal shooting improved when I focused less on the academics of BR and more on the flags, gun handling, etc, etc. Meaning trigger time and lot of matches across many different ranges.

-Lee
www.singleactions.com
Click to expand...

Well said, I couldn't agree more.

That said.... simply YES, ES becomes a real thing at 600-1000. As I've said in this thread, I rarely weigh or chrono short range stuff, no need nor gain.

As an addendum, trying to find tuning nodes while loading to super low ES is impossible. "Tuning" IS compensating for the velocity variables.....so you absolutely need the variable velocity to find nodes. But once you've established tuning node(s) loading to the kernel, dead center of the node (or low-end in the morning) can pay huge dividends. Especially for Score.

"SD" is completely useless unless you shoot off yer hindfeet or somesuch. For BR it's not even worth including in the dataset

But for tuning at 600 (something I can do out my window) shooting THROWN charges on a live camera feed so's you can treat it like tuning at 100-200 then WEIGHING loads in the center of the window.....is like cheating. My 600yd backer is only 4'X4' but I can shoot a lot of groups on it.

one'a these days I'll get a drone to make it even easier ;)
 
FBecigneul said:
Isn’t that wonderful? You can weigh single kernels and had an ES and SD of Zero.Now, post the targets that made all that worthwhile. Matter of fact, you’ve never posted any pictures of targets or match results. That is where rubber meets the road.
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You know it's kinda' weird..... you say stuff like this a lot.

In simple fact I've posted dozens of groups, pix of Match results, pics of Match targets and have documented a lot of this again on Youtube for all the world to see. I can/will on command videotape myself shooting, pick a day and date, holding a newspaper in the background but WHY???....A simple innernet search shows your allegations for what they are but that's not important.......

What's important to me is that you have this "thing".... I don't know what it is..... and the fact that you or anyone who cares can just go LOOK AT results any time should be enough, but it's not.

It's easy to do, and maybe _should_ make me happy to show you wrong..... but it doesn't


it just makes me sad.


That said..... rows and rows of groups fired in my back yard don't really show anything except that it's dead easy to make a gun SHOOT if it's built right.
 
alinwa said:
As an addendum, trying to find tuning nodes while loading to super low ES is impossible. "Tuning" IS compensating for the velocity variables.....so you absolutely need the variable velocity to find nodes. But once you've established tuning node(s) loading to the kernel, dead center of the node (or low-end in the morning) can pay huge dividends. Especially for Score
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I agree Al. Like most, I pre-load for Score and make adjustments with my tuner if needed during the day. I paid a fair clip for my FX-120i and use it.
Every charge for my .30 Stingray is weighed to the nearest 0.02 gr. I believe it has helped my scores. But as we've discussed, it isn't because ES's and SD's are shrinking....it's because it keeps me more around the center point of the node. Or worse, I throw a charge that's way out and come off the node completely. I'm pretty good at staying within +/- 0.1 gr with the LT's, but I'm not a robot. If you're going to pre-load, I'm all for weighing. And if you're going to weigh, be as accurate as possible.

-Lee
www.singleactions.com
 
FBecigneul said:
So just shut me up and post one picture of match results where you did well.
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Why on earth would I want to "shut you up??"

As I've stated clearly many times, I value not only your opinion but the right for you to have it....Rock On Man, opine all's you want and I'll never try "shut you up"

It's a DISCUSSION forum fer cryin' out loud!

(insert 'confused' emoji here)
 
OK..... so this just posted up on youtube today. For me it's a blast from the past because I recorded it over a month ago before the rain stopped.

It made me shibber and grin this 95* day in the PNW.

This is where I'm concentrating my efforts right now, doing something which has never been done nor even attempted before.....but the RELEVANT part is that this case takes 250gr of powder, it is NOT neckturned nor are cases prep'd in any meaningful way but by weighing charges TO THE KERNEL OF POWDER I've got ES down in the dirt. I've only fired it a few times at this point, it's one of 4 of the 50BMG's in this series of tests, but I'm not fighting ES

If this series of 50BMG hunting rifle do not print ROUND holes (trust me, 1/4minute groups in 50cal look awesome) I will have failed. In front of God and Frannie and EVER'buddy....

I've managed to document the buildup of 4-5 PPCs and a half-dozen other rifles showing that YES it's doable to make a bolt-in shoot as well as a glue-in

But this is a whole nuther world!

Think I be go CHOOT! some more..... right now

https://www.youtube.com/watch?v=C0jCEu8yVyY
 
rsmithsr said:
just remember the typical 5 shot 10 shot sample size used to produce an sd/es number is just not valid. the science is based on a large data set 1k, 10k..not 5. its a nice number when it is small and the group is small........but it not very scientific in our use
Click to expand...

You had stats 101 and maybe more.
P.S The Bruce and Jenny joke was really good.

Mort
 
I haven't used

My chronograph in years, instead rely on the size of the groups I get. I have weighed to as close to zero and I was able to get to and make sure each loaded round is exactly the same length as close to where the bullet will engage the lands as possible. I have been able to satisfy myself with this method for over 15 years. I am currently using a Sartorius Enrtis II Essential line Analytical balance I paid handsomely for because I wanted to know as for sure as I could be that the balance was being truthful. I'm satisfied that it is. Yes, I see a difference.

A lot of this is based on what one believes in and trusts and is only as good as the balance one uses to weigh with. I have a V4 on order and due next month, basically to speed the process up. While I have gone past it as far as being competitive at shooting is concerned, I can still tune rifles.

Pete
 
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