High E.S. Upon Load development

[Suicideprodigy]

Started load development on my 300wm with h1000 and berger 215s 215m primers. .060 OTL.

Virgin brass ran through a expanding mandrel insuring .002 neck tension, verified with calipers. And yet I'm having horrible ES and SD. Am I missing something major or am I just not at a node at all. Graphs for work up and 10 shot groups on what I assumed were interesting starting points for charge will be attached. Please help my dumba$$ out!

 

[OREGUN]

What were these horrible ES/SD numbers? How many shots in the test group? How many shots per charge weight in your graph?

assuming each charge weight included at least five shots, I’d have tried 77.1 grains…there are three charge weights around 77.1 that stayed within 25 Fps. If that’s only one shot per charge weight, you proved exactly nothing.

your ES at 78.4 doesn’t seem terrible over ten shots. How far below “overpressure” was that?

your ES/SD will improve between virgin and 1x brass so don’t be too focused on that just yet. How were the groups? At what distance?

 

[Suicideprodigy]

What were these horrible ES/SD numbers? How many shots in the test group? How many shots per charge weight in your graph?

assuming each charge weight included at least five shots, I’d have tried 77.1 grains…there are three charge weights around 77.1 that stayed within 25 Fps. If that’s only one shot per charge weight, you proved exactly nothing.

your ES at 78.4 doesn’t seem terrible over ten shots. How far below “overpressure” was that?

your ES/SD will improve between virgin and 1x brass so don’t be too focused on that just yet. How were the groups? At what distance?

So don't be so focused on ES until fire forming? What would be a ES you would be happy with seeing in a 3-5 shot? I can't remember off the top of my head but I would like to say most groups of 3 were in the 1 moa range but it seemed to be more vertical than horizontal spread. These were done at 100. next test I will definitely go further than that as 100 doesn't show much. Highest I took charge to was 78.6 and still didn't see pressure signs.

 

[RldrNewby]

How much vertical are you seeing? Just a thought, but a 300win mag can be a handful of recoil to deal with, so I’m wondering if the vertical could be something minor related to how the heavier recoil is reacting to the way you have the rifle supported? ie. Using sandbag up front versus a bipod with a preload or no preload, butt stock resting on a shooting bag versus free supported by hand, and shoulder squared to stock versus angled. If the shooting form techniques used for your test have gotten you under 0.5moa plenty in the past, & nothing has changed, but you see vertical, maybe it is the load, or possibly a seating depth your rifle just doesn’t prefer with that bullet or powder combo. Do you have 3 to 5 shot group SD/ES info for the possible nodes you explored? I wouldn’t be too worried about group sizes until you’ve found the load with the lowest SD/ES and completed a seating depth test. If still getting bad numbers or vertical afterwards, something is going on.

 

[918v]

Just because you expanded virgin brass with a mandrel doesn’t mean the neck is gripping the bullet correctly.

 

[OREGUN]

I usually see an improvement in velocity consistency after the virgin brass is fireformed. Groups mean more to me than ES/SD, which usually needs a much larger sample size to be valid than you’d be willing to shoot (at LEAST 20 in the sample). What’s your capability with the rifle using a known good load? What’s your requirement for this rifle…1 MOA, < 1MO, .5MOA? How much confidence do you have in your charge weight consistency? I like to see the smallest ES I can manage based on the reloading techniques I use as a means to increase vertical consistency at distance but Ill take small groups (5 shots) at my intended distances over small-sample-size statistics.

In my process, I initially use a charge weight “ladder” of 3-5 shots, 1/2 grain apart, to check pressure limits, watch initial velocities to see if I’m in a “normal” range, and see if there is a charge weight range that clearly shoots a little better…I do this at either 100 or 300 and it’s never failed to show me a charge weight range wherein the groups shrink noticeably across perhaps 1 grain or so. I don’t know which “method“ this is but it’s what I’ve always done and it works for me despite being absolute sacrilege to people who are devoted to their chronometer statistics.

Once I’ve got a charge weight I like, I’ll test some seating depths, again looking for group size at 100 or 300 yds. Again, there’s usually a range of seating depths that shoot noticeably smaller groups. Once Ive found that seating depth range, I’ll load up enough to shoot at least 5 at each distance, out to as far as I can shoot, and only then will I run as many of them as is convenient over a chronometer to look at extreme spread.

If your reloading techniques are consistent, specifically regarding charge weight and how much you resize the brass, and you are even remotely consistent behind the rifle as a shooter, you should expect to see reasonably low extreme spread and SD numbers. You’ll have to decide what “reasonably low” is for you. Am I doing the math right on your 78.4 numbers…ES is 22? That would be acceptable for me.

It’s entirely possible that if you arent used to the heavier recoil of the caliber, your technique could be causing the groups to be bigger then would otherwise be indicated.

 

[918v]

I usually see an improvement in velocity consistency after the virgin brass is fireformed.

I see that as well.

I think virgin brass is not quite ready for loading as is. And a mandrel by itself is not enough. I found that out one day when expanding virgin Lapua brass. I noticed that some of the necks were tighter than others and offered more resistance to the mandrel.

Some people FL size virgin brass first so the neck gets worked over once before they load the brass. That way the grip on the bullet is consistent.

I also recommend graphite dry lube in the neck.

 

[OREGUN]

Depending on what I’m loading for (magazine feed or single feed) I will sometimes run a standard expander mandrel through the necks of virgin Lapua… sometimes I don’t though and I just accept that seating pressure in that initial loading is probably not going to be super consistent and realistic to what I’m expecting in future reloads.

I can never bring myself to FL size new brass.

 

[918v]

Depending on what I’m loading for (magazine feed or single feed) I will sometimes run a standard expander mandrel through the necks of virgin Lapua… sometimes I don’t though and I just accept that seating pressure in that initial loading is probably not going to be super consistent and realistic to what I’m expecting in future reloads.

I can never bring myself to FL size new brass.

You could always neck size it. A good handloader can never have enough dies.

 

[OREGUN]

You could always neck size it. A good handloader can never have enough dies.

Like any kind of tool, I never turn down an excuse to buy a new one.

Currently, I’m enjoying “how little brass prep can I get away with doing“….which is further reduced by using premium brass. When I was buying Winchester brass, I did have to do a little more (dented necks, wonky cases, etc) to get them ready.

 

[RldrNewby]

I usually see an improvement in velocity consistency after the virgin brass is fireformed. Groups mean more to me than ES/SD, which usually needs a much larger sample size to be valid than you’d be willing to shoot (at LEAST 20 in the sample). What’s your capability with the rifle using a known good load? What’s your requirement for this rifle…1 MOA, < 1MO, .5MOA? How much confidence do you have in your charge weight consistency? I like to see the smallest ES I can manage based on the reloading techniques I use as a means to increase vertical consistency at distance but Ill take small groups (5 shots) at my intended distances over small-sample-size statistics.

In my process, I initially use a charge weight “ladder” of 3-5 shots, 1/2 grain apart, to check pressure limits, watch initial velocities to see if I’m in a “normal” range, and see if there is a charge weight range that clearly shoots a little better…I do this at either 100 or 300 and it’s never failed to show me a charge weight range wherein the groups shrink noticeably across perhaps 1 grain or so. I don’t know which “method“ this is but it’s what I’ve always done and it works for me despite being absolute sacrilege to people who are devoted to their chronometer statistics.

Once I’ve got a charge weight I like, I’ll test some seating depths, again looking for group size at 100 or 300 yds. Again, there’s usually a range of seating depths that shoot noticeably smaller groups. Once Ive found that seating depth range, I’ll load up enough to shoot at least 5 at each distance, out to as far as I can shoot, and only then will I run as many of them as is convenient over a chronometer to look at extreme spread.

If your reloading techniques are consistent, specifically regarding charge weight and how much you resize the brass, and you are even remotely consistent behind the rifle as a shooter, you should expect to see reasonably low extreme spread and SD numbers. You’ll have to decide what “reasonably low” is for you. Am I doing the math right on your 78.4 numbers…ES is 22? That would be acceptable for me.

It’s entirely possible that if you arent used to the heavier recoil of the caliber, your technique could be causing the groups to be bigger then would otherwise be indicated.

I’ve been reading a lot of posts where folks are using ladder load developments, and I’ve been thinking more & more about revisiting that method, and trying it again. The first time I tried it, I was brand new to reloading, and at that time, didn’t have near the reloading bench skills & equipment that I’ve progressed to now, plus, I had only fired one round at each charge weight at 300yds. My results were inconclusive & it left me scratching my head, so I bailed on ladder prematurely, & experimented with other methods. My overall group of the ladder test I tried was basically just over 1MOA at 300, with no discernible patterns or clusters in successive charge weights. The more I’ve researched ladder, the more I believe it’s value could be really beneficial for me to try again at further distances out, say 500yds or more, with at least two shots at each charge weight. I will definitely be adding trying ladder to my to do list sometime in the future.

I guess my point in all that was to say that I think most mainstream methods do work, it’s just boils down to preference, & what each individual is capable of, along with their preference. I’ve been doing an OCW style method where I’m shooting 3 shot groups at 100 in incremental charge weights, & evaluate for poi shifts, group sizes, & I also collect Chrono data for SD/ES. I realize the small sample sizes in the truest sense aren’t statistically valid, but for me, it does seem to work out that if I have two charge weights in a row with nice groups exhibiting SDs in the range I can live with (usually the lower end of all the groups tested), somewhere in middle of those two increments typically end up being my best performing load after seating depth tests have been done. I then do load verification at larger sample/group sizes, and see how they shoot at distance. Maybe not the best method, and while I don’t see true flat spots, it does seem to correlate that where I end up at is a less linear velocity increase between charge weights. It’s worked for me, but I’m really considering giving ladder another try. I can’t expect to get better at this craft unless I further my understanding of it, & remain open & willing to learn techniques. Also interested in Mandrel techniques as well. Right now I’m using a Redding FL Bushing Die with .289 bushing, with the stock .262 stem, but it is working out fairly well.

 

[918v]

Case prep has a tremendous influence on load development. If you have not mastered case prep then you will not have good repeatable results.

OCW is valuable in that it demonstrates how powder charge affects poi. Another variable that affects poi is coal. So finding your optimum charge weight and then finding the optimum coal will negate the former and prioritize the latter.

Plotting coal vs charge weight and monitoring poi shift is the best method I have found.

 

[OREGUN]

Case prep has a tremendous influence on load development. If you have not mastered case prep then you will not have good repeatable results.

OCW is valuable in that it demonstrates how powder charge affects poi. Another variable that affects poi is coal. So finding your optimum charge weight and then finding the optimum coal will negate the former and prioritize the latter.

Plotting coal vs charge weight and monitoring poi shift is the best method I have found.

We might have slightly different interpretations of the phrase “case prep”. Lately I’ve literally been pulling virgin Lapua out of the box, loading it and going to shoot. In that regard, virgin Lapua brass gets essentially no “prep”. Although I also don’t expect it to provide the ultimate accuracy or velocity consistency. Once I have 1x fired brass, only then do I worry about resizing it exactly the same way, maybe chamfer the case mouth, establishing neck tension, graphite in the necks, those kinds of things. I only trim as needed, I definitely don’t weight sort my brass, and my days of doing things like neck turning, reshaping primer pockets or flash holes, etc. are definitely over. I’m also not trying to shoot for absolute group accuracy as in Benchrest or F class. I do however, expect my rifles to shoot less than 1/2 MOA at any distance.

The way I see it, there are a number of variables that affect a consistently accurate load: the size of the brass (headspace), the weight of a charge, and the length, measured any way you want to measure it, but realizing that two things change, the distance from the bullet to the rifling and the free space in the case below the bullet. You can run yourself ragged by trying to chase all those variables at the same time. In the past I’ve always tried to resize to .002” below “fired size” but I recently have been experimenting with resizing a little more than that and I’ve actually had better results with brass that resized .004” below the fired size measurement. I usually start with charge weights using bullets that are seated about .020” away from the rifling. If I find a charge weight that I think I like, I’ll usually try seating deaths that are slightly closer and then slightly farther away from the rifling…usually in .003” increments.

Does that prioritize length over charge weight? Maybe, but you have to start somewhere.

 

[Rocketmandb]

I usually see an improvement in velocity consistency after the virgin brass is fireformed.

To quantify, when I first got my ADG brass for my 300 PRC, I wanted to measure pre/post forming. Pre was about a 12 SD (if I remember correctly). Post was back where I expect in the 6 range.

 

[Steel head]

To quantify, when I first got my ADG brass for my 300 PRC, I wanted to measure pre/post forming. Pre was about a 12 SD (if I remember correctly). Post was back where I expect in the 6 range.

I saw similar numbers with 7 saum and 338 edge ADG brass.
With new brass I just load it mildly and shoot steel with it.
I don’t get serious with it till it’s once fired and barrel is up to speed.