Only 3 shots? or… 7? maybe 5 or 10. What’s statistically best?

Reader Mike left a comment that pointed to Dan Newberry’s Optimal Charge Weight website and reloading technique.  Thanx, Mike!

Reading through Dan’s writings, I have to say there’s a lot of sound reasoning in there — or what sounds like sound reasoning, because I’m still new to reloading so it may be my naiveté talking. Googling on the topic turns up a lot of people who use his technique and that are satisfied with the results, and I’d like to try Dan’s approach especially since prior attempts at using the ladder technique didn’t quite get me what I was after. But I’m struggling with one point.

Backing up a moment, I do think there’s something to what Dan says. For instance, he points out how Federal Gold Medal Match .308 ammo is a top performer out of so many rifles. But how can this be? A lot of handloading lore revolves around the notion that every rifle is different, even two of the same rifle model that came off the production line physically adjacent to each other. I don’t deny that, but if truly that mattered so much, there’d be no way factories could develop such high-performing ammo, right? One place Dan really gets on with this is the issue of “seating off the lands”. He doesn’t deny there’s something to it, but he doesn’t put tons of stress upon it like others do. Again, look at Federal GMM, because there’s no way it can be set at some ideal distance off the lands because every rifle is different. So while perhaps distance off the lands matters, is it that critical to the process? Dan argues there are other things more important. That isn’t to say the distance isn’t important; I figure if you are wanting to wring the utmost performance out of a particular gun then yes it’s another variable to tinker with to see how it affects your loads for that gun. But first, worry about other things. Read Dan’s website to understand his reasoning and approach.

I think the reason that struck me so much was when I first tried my hand at .223 Rem reloads, there was greater discussion of this issue because Barnes bullets apparently can have a little more of an issue with the distance they are seated off the lands. So I kept agonizing and wondering if this was my problem, if that distance from the lands (or conversely, the seating depth) was my issue in some way. But lack of money to keep buying those expensive Barnes bullets gave out (not to mention my patience). So going into this new round of reloading, I’ve been struggling to find a COAL. For instance, so much reloading recipe data out there mentions the bullet, the primer, the powder, the case… but so often there’s no mention of the COAL. It’d be nice to know the overall length! Most solid publishers of data always provide it, but people often don’t. As a further example, since I’m going to make plinking loads of a 55gr FMJBT and use Ramshot TAC, I discovered that m4carbine.net has a “board standard” of using 55gr FMJBT’s with 24.5gr of TAC to get a generally good-performing plinking load. But… what’s the overall length? I scour and have yet to find it. So I did some measuring of factory and other reloaded .223 rounds that I have and well, my conclusion is to not sweat it so much. These particular bullets have a cannelure, and I’m just going to load it there and see how it does, not sweating it until later in the process. Thank you Dan for freeing me of fretting about this particular issue. 🙂

But the thing about Dan’s technique that troubles me? Only firing 3-shot groups.

Granted, you shoot a lot of 3-shot groups, but each are different loads (powder amounts). So really, you are trying to determine performance of that load based upon a small set of data. I’ve done enough shooting to know that 3-shot groups are great for the ego, but 5 shot groups tend to be a little more honest. I think I read in the Speer manual (if not there, read it from some reputable source) that after much analysis they concluded that 7 shots was the statistically best balance between shooting enough to get a good picture of performance but also keeping the number of shots low for cost, barrel wear, time, trouble, etc. purposes. Plus if I only load 3, what if I get an honest flier where I know I pulled the shot? That’s very easy to do when I’m testing loads at the indoor range… just as the trigger is about to break, someone opts to shoot their 300 Win Mag in the next bay and it rattles my fillings and there goes the shot. So now what? Does that mean I should load 10+ rounds of that powder charge just in case? and if something messes up, start that group over? But then, you’re supposed to fire in a round-robin fashion to try to combat effects of heat and so on, so if there’s one mess up do I have to start over?

All those questions aside, it just feels like 3 shot groups isn’t going to give me what I want. But then, maybe I’m looking at it wrong? Honestly… as I write this it’s making me think. If I’m perhaps (now better) understanding what Dan wrote, it’s not looking for a tight grouping but rather how the groups are generally printing… looking for groups hitting the same general area on the target. Thus, you start to find the harmonic vibration point for that rifle. Once you know that, then you can work to refine it to tighten up the accuracy part, fine-tuning the powder charge, fine-tuning the seating depth (which of course also affects distance off the lands).

Hrm. Is that the point?

Maybe then yeah, taking the more traditional Speer approach isn’t the way to go about it.

Hrm. Maybe I need to just shut up and blindly try Dan’s approach for myself and just see how it goes. 🙂

In related news, Mike also suggested I try out a Weaver T-36 to help me develop loads. I think that’d be great, but it’s going to have to wait. Too much money has gone out the door, so there’s no way I can afford that right now. I’m just going to pull the 3-9×40 and mount off my 6.8 hunting rifle and use that for now. It’ll just have to do. I figure it will be good enough since I am looking to make a plinking load and not wring out every last millimeter of accuracy.

13 thoughts on “Only 3 shots? or… 7? maybe 5 or 10. What’s statistically best?

  1. I have to load my .223’s (and my M1 Garand .30-06’s) to magazine length, so seating out to lands is a non-issue, and I shoot Sierra Match Kings exclusively since I’m a non-hunter. With a 1:7 twist both my match and carbine rifles get the 69-grain HPBT’s.
    When someone says “XYZ is a top-performer” to me it sounds like that has to be in relation to something – and usually (could-be) that is the second shot in relation to the first, as the first group develops – so I would wonder what bullet the Federal .308’s use and what twist (and what length) the barrel is, as far as “top performer” goes? Performance on critters or performance on targets? Short barrels are stiffer and can “game” the paper target.
    I don’t have any scopes, I just shoot across-the-course iron sights – and they cost too much. 😉

    • So you load your .223’s to 2.260″… at least, that seems to be the inside length of my P-Mags. Or thereabouts? That is also the max length for .223. I thought about doing that too.

      Oh I should also say, when I tried using one of those Stoney Point gauge things from Hornady to measure the distance to the lands and such, it did not work out… it would have been tooo long, longer than 2.260″. But that particular AR did have a 5.56 chamber so, maybe that had something to do with it?

      In terms of “top performer” I guess the intent there is to say that Federal Gold Medal Match is a very accurate ammo. It’s match ammo, so it’s gotta be for punching holes in paper. And then, probably comparing shooting that ammo in X gun vs. shooting say Winchester White Box or some other cheap plinking ammo in X gun. That you’ll get better groups out of the GMM. That’s what I figure he means.

      But then it also sounds like it doesn’t necessarily matter the gun… that I guess it’s always in that gun, relative to using “cheap ammo” vs. “match ammo”. And then that overall the GMM gets such great performace across guns Federal can’t account for… thus is something like “distance off the lands” truly THAT critical? Sure it matters, but my read is that there are a lot of other factors to get straight FIRST, then you can go tweak your OAL (and thus distance off lands).

      You are the man… shooting irons. My eyes are so crappy….. *sigh*

  2. Oh my eyes are awful crappy too, I shoot at a fuzzy blob!
    I just do what the Sierra manual tells me to do with H4895 – my only powder. 🙂 The Stony-Point gauge defeated me too, but that was when I was trying to measure for the Krag – the chamber lede was so long it might have been in another rifle…
    I found that I couldn’t make a handload with my components that was as good as the Blackhills Match that I bought in a moment of (huge) fiscal solvency – a top performer on targets (and enemy combatants in the Sandbox), but something you shouldn’t use to shoot at animals!
    My buddy the High Master says the whole thing about seating out to lands and all is just riffle-weenie stuff from benchresters, what got him there was shooting and practicing a LOT – trigger-time is everything. More time than I have.

    • No doubt! trigger-time is the thing. As it is with rifle, the gun and ammo shoot better than I do.

      Well, I’m hoping to spend some time at the reloading bench this weekend. We shall see. I’ll probably just ignore my questions and just try to follow the OCW method as strict as I can. Let it be what it will be. 🙂

    • Hey, I have those tools!!!

      Good video.

      I think that this point in my “clueless n00b” career, that I’m going to just blindly try the OCW method and see how it goes. I mean, I tried that “OAL tool” stuff and it was WAY beyond the OAL for the cartridge. So while I don’t discount the importance of it, I think at first there’s other things to worry about.

      Again, I think I should just trt the OCW technique straight-up and see how it goes.

  3. I agree with you on the 3-shot thing.

    When I started loading for .223 just after I finished building my AR, I did 3-shot workup groups because someone suggested it to me. This was a Bad Idea. I had not yet invested in a lead sled, and i didn’t have sandbags to bring to the range. I simply shot off the bench supported by my hands, using iron sights that i wasn’t quite comfortable with yet. Looking at the groupings on paper was useless. There were so many variables and such a small data set that there was no way to judge what a particular charge was doing.

    I got a lead sled and started doing my workups in 5-round increments. It made quite a difference. This also gives more chronograph data to correlate with. With 5-shot groups, I can see which charges are the most consistent in the data, and see that correspond visually on the targets. They don’t always correspond, of course, but it does help validate when I have a good load going.

    By the way, have you tried out the 8208 XBR powder yet? I’ve done some workups with it, and have had good results so far. It seems to be good both for lighter (55 grain) and heavier (69 grain) bullets out of my gun, so it may be something to consider as an all-around powder.

    • Yeah, get me a Lead Sled and it’s a different matter entirely. 3 shots could work if you can eliminate all other factors… but I’m human, I’ll flinch or pull a shot sooner or later.

      Makes me think what I should do is load 5 rounds, just in case. Shoot 3, but have 2 more on hand if needed. I really want to try that OCW approach as “by the book” as I can to see how well it works out. Other folks report good success with it, and there seems to be much logic behind it so….

      I have not yet tried the XBR powder, but hearing your results are encouraging. I’m really wanting to try it out for 6.8 SPC loads, because there’s not a lot of data on it there and I am curious to see how it compares out.

    • BTW that XBR powder. How well does it flow out of your meter? Not sure what you use to drop/measure your powder, but I’m curious how well, easily, and consistently the powder throws. For instance, when I did Varget out of my RCBS stand-alone powder drop it would sometimes “lock up” because a grain got in the way and the drum couldn’t rotate… a little wiggle or “chop” and things would get going, but it’s not good for grains to get chopped like that. It’s even more important on my progressive press to want to get everything “perfect each time” without hassle. That’s one reason I’m using TAC, because it flows like water and should easily throw a charge with no hassles and no change in weight across throws.

      Supposedly the XBR meters and flows well such that I shouldn’t have any problems, but it’s hard to find any real data on that out there.

      • The XBR powder is pretty decent to meter. It’s not as nice as TAC, but it’s consistent. It’s definitely much better than Varget. It’s got a similar shape, but the granules are much smaller (and proportionally shorter), so it doesn’t hang up easily.

        I use a Lee Perfect Powder measure for my loading.

  4. Sorry to be chiming in on this so late HSOI. I’ve been out on the truck for nearly a year straight!
    On three shot groups. I use those as a very basic starting point. I use the same components, but vary my powder weight. I also start out with the book recommended COAL. On the 270 for example, I loaded three rounds each at 55 grains, 57 grains, and 59 grains of R22 powder.

    Then I went to the range, and shot the three sets into a single target. Marking each set with a color indexed to the particular load. Stringing was inconsequential because the groups were wider than the strings were. In any case, the 57 grain load was the tightest.

    Back to the bench. I set up a load at 56.5 grains and 57.5. Repeated the above process, and went and got an inexpensive Winchester rifle rest. The results were astounding to say the least!

    I set up 5 each at 56.4, 56.5, 56.6, and 56.7 grains. Being blessed with a range only 10 minutes away I was able to perform pretty quick evaluations, and 55.6 was the clear winner in the XL 7 Marlin rifle.

    Later, I tried altering the COAL, and using the original settings as noted in the Sierra book gave the best performance. By the way, giving them a call can really help reduce the headaches!

    As a side not, the Game King bullets at 130 grains shot nearly identical to the Match King bullets.

    • No worries. I recall you went on hiatus. 🙂

      You’re fortunate the range is so close. That’s part of my problem: distance. So it makes me want to load as much as possible to minimize the range work.

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