The things we do that effect accuracy, or don't

I like the idea! I can probably do case and bullet weights, I've got a pile of 7mm components.

If a guy is going to do it, do it right. The sample set required is determined by the overall population. 40 shots may well not yield any discernible trend, or worse, it may reveal an opposite trend to the actual overall result. There’s a user here who posts a lot of YouTube videos which comes to mind - thousands of shots, but absolutely terrible experimental design, and insufficient precision to make any real conclusions based on his observations. BUT!! The conclusions based on his poor data set are his conclusions, and they get passed off as if they were meaningful...

A guy throwing charges might have a very different conclusion than a guy measuring to the nearest 0.015grn. An inexperienced guy doing a test midway between nodes (because one day, way back, it shot a half inch group) might get a completely different result for bullet weight sorting tests than a guy loading smack in the middle of the node. Primer choice might make a big difference based on the powder used, or the type/size of primer, whereas other powders or other cartridges may see a very different result.

So the unfortunate reality is this: your list describes thousands and thousands of shots for load development before a guy even gets to the comparative data sets. Thousands of dollars in barrels, bullets, powder, etc.

Also - you gotta define what “neck tension” means. Neck sizing, neck turning, expanding with a mandrel instead of in the sizing die, neck size only, body plus neck as separate steps, annealing, amount of tension, throat clearance, etc... if a guy starts with new Lapua brass and expands inside a standard full length die, fired in a custom tight neck chamber, he likely has more consistent neck tension and support than a guy who loaded 10x Winchester brass fired in a factory chamber, neck sized and expanded on a mandrel die. But of course - if you flipped the roles, the guy with the custom barrel will likely outshoot the factory rifle no matter what.

I love the idea, but I gotta say, I expect to see a lot of info come forth which raises more questions than it answers, just like any of the other “science” of this type flooding the internet these days.

Nature Boy said:

There are always multiple discussions running where the question is:

Is it worth it to do (____)

Worth is usually defined as improving accuracy, precision or consistency of down range results. Sometime we take the extra time to prove that doing something vs. not doing it has merit, but more often than not we take it on faith based upon conventional wisdom or forum feedback.

I propose we take some of these "things" and do some testing to see if we can discern their value. There will have to be some established predicates for these tests. Looking for feedback from you all to flesh this out and help with some of the testing if you find that sort of stuff enjoyable.

So here's a short list of some of these "things" that often get debated regarding their value:

1. Deburring flash holes (there's a thread running now on that, which gave me the idea)
2. Sorting brass by weight
3. Sorting bullets by weight
4, Sorting bullets by base-to-ogive measurement
5. Wet vs dry tumbling (my favorite)
6. Run Out
7. Primer brand x vs y
8. Neck tension

Some of these are either/or so a test might involve 2 sets of 4 groups, 5 shots each (4 groups for the "not doing the thing" and 4 groups for "doing the thing") 40 rounds total.

Then you have the issues where you're looking at variable data like bullet weight. For instance you could sort bullets where you get most of your 168 SMKs measuring 168g +/- 1g. Take 20 of those and compare them to 20 from the extreme ends (highest and lowest) of your weighed bullets. In this case, if you saw no discernable difference between these two sets, you'd never weigh another bullet in your life.

If the test is set up properly, I don't think you'd need to be a world class record holding bench rest champion to do these tests. As long as you and your rifle are reasonably consistent, the comparison between sets should reveal meaningful results.

So what do you guys think? Is this worth doing and do you have an interest in participating?

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I like this, I'll be watching, I for one don't do a lot of those steps but I find results of such inquiries interesting. I'm a collet neck sizer, ultrasonic cleaning, winchester primer (cuz they're all that's guaranteed to be in stock around here) using feller, and haven't yet begun to ask competition level performance of my gear, but hopefully the responses here will be educational.

Some of these you have already done on your F Class adventure. aka Run out, primer, brass.

It going to be hard to do but I've already done some of them to satisfy my self in quest for a more accurate round.

I've done different primers on most rounds I shoot. The problem is I don't do a complete load workup when I change primers. I just swap primers and see if the groups change shooting them side by side. I showed a neighbor one of my test and he was surprised of the difference. But a lot if times there is no difference. So for me it's a hit and miss.

I do sort brass by Year if I'm shooting military brass. I've also discovered due to production runs I have to tweak the OAL 0.005-0.010" at most to keep all the yrs consistent with each other.
I've also sorted by weight ±0.5gr, seen differences there too. But it all depends on how sensitive your loads are. If your in a big node it may not have a impact. I currently have my Starline 6.5 CM sorted by weight. I always do this when I'm testing loads. Trying to minimize variables. I've never sorted bullets. It may require someone with some extraordinary skill to tell a difference, besides the hardware to utilize it.

Neck tension is going to be a hard one. Like you I anneal every cycle so I have the same neck tension throughout it's life.

So I'm guessing I'm in. I have a lot of data in notebooks but there is no organization to it except by date. The crony data and targets are filed on a app. The big issue is bring it all together.

Many people have opinions but they have never tested their theories with a truly accurate rifle. This is mostly because they have never owned a rifle accurate to prove small details make any significant difference.

I guess you could do all of this, but to what end? My target shooting has definite limits due to eyesight and ability. Inside of, say, moa or 1.5 moa depending on the rifle, the nut behind the trigger will likely make a much bigger difference than the rest. My need for hunting accuracy is 2 inches at 100 yards for everything but elk. For them I need 3 inches at 200 yards. Even those figures are probably tighter than necessary. As for handgun, minute of beer can at 20 yards or so is plenty. I wish greater perfection meant more, but in my world it is largely unnecessary.

Nature Boy,
IMHO An excellent idea!!
A loooong time member bds has comparisons of these and MANY other questions not listed here.
check out:
https://www.thehighroad.org/index.php?search/27990576/&q=myth&o=relevance&c[node]=15&c[user][0]=113916
Or use search for Myth Busting, Reloading myths busted or confirmed, THR Group Project-Pistol or THR Group Project - Rifle.
I have found that bds (among many other THR members) have given much excellent test results and advice on improving your experience and enjoyment of reloading on many reloading topics.
JD

What about bullet seating depth, Nature Boy? Or do you think that might be too rifle specific to mean anything to someone using a different rifle? I mean, I've heard that some rifles shoot better groups with the bullets touching the lands, or just barely off the lands. Never experimented with different seating depths myself though.

.308 Norma said:

What about bullet seating depth, Nature Boy? Or do you think that might be too rifle specific to mean anything to someone using a different rifle? I mean, I've heard that some rifles shoot better groups with the bullets touching the lands, or just barely off the lands. Never experimented with different seating depths myself though.

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This was huge for me. Tried a bigger cast slug in 3006. Seared at the crimp groove and it is barely on pare at all at 50 yards. Bump it out to the next lube groove and it was hard not to get at least 2 inch groups at 100 yards.

Breaking in a rifle barrel. Its obsessed about to the point that people have debates over the true value in it instead of just pulling the trigger. I've bought two Remington 700 sps's in .308 and the one that wasn't properly "broken in" consistantly shot dime sized groups with my reloads. The "broken in" rifle shot 1"-1.5" with an identical setup and a separate load worked up but couldn't match my "improperly broken in" rifle. Im not saying one way is better than the other. I just haven't seen a difference in a broken in barrel. Someone will come along to chew me a new one. Just my experience.

I stand in the middle of a silo and close the door and try and hit a wall. I'm about 50 / 50. I sucked 40 years ago and with thousands upon thousands of practice rounds, I have not gotten any better.

.308 Norma said:

What about bullet seating depth, Nature Boy? Or do you think that might be too rifle specific to mean anything to someone using a different rifle? I mean, I've heard that some rifles shoot better groups with the bullets touching the lands, or just barely off the lands. Never experimented with different seating depths myself though.

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I've had better experiences with a jump on my bolts. But like you said, kinda specific to mean anything to anyone else.

I wish you the best of luck. To find answers, this is truly a monumental task. The variables are huge.

I can tell you my experience. I controlled variables and experimented with everything described as best I could to make a M70 with a 26" barrel shoot. In 5 years of playing and learning I had a total of 1 group under an inch. I was headspacing a belted magnum on the shoulder, even. Then I got wild and cut 4" of the barrel off by hand with a hacksaw. Average group sizes shrunk in half, and I could occasionally shoot 5 shot, 100 yard 1 MOA groups off the bench. Most of us know why it got better, this was my learning experience. But how else does someone learn - I get what you are after.

That same gun now has a Hogue pillar stock, Burris scope and Krieger barrel. Load experimentation is complete for this gun. The Krieger barrel took care of that. Now I shoot Sierra 175's exclusively, off hand and resting, to improve me. Heck, off a rest it shoots 1 inch groups at 200 yards now.

I look at my detailed notes from experimenting days, and I honestly wonder if I will use that information to the level of detail recorded. I don't need the notes to remember most of what I learned. For example, good loading techniques such as those you described can make a 3/4" gun a 1/2" gun. But if the gun is shooting 1.5 or 2 inches with all or most loads, I learned to look at the gun and not the loads.

Ttrl

Is it worth it to do (____)
Could test powder position to confirm Hatcher.

Powder position in case matters (Julian Hatcher, Hatcher's Notebook):

When the powder does not competely fill the cartridge case, the
velocity will vary depending on w'hecher the bulk of the powder
is nearer the primer end or the bullet end of the case.

brewer12345 said:

I guess you could do all of this, but to what end? My target shooting has definite limits due to eyesight and ability. Inside of, say, moa or 1.5 moa depending on the rifle, the nut behind the trigger will likely make a much bigger difference than the rest. My need for hunting accuracy is 2 inches at 100 yards for everything but elk. For them I need 3 inches at 200 yards. Even those figures are probably tighter than necessary. As for handgun, minute of beer can at 20 yards or so is plenty. I wish greater perfection meant more, but in my world it is largely unnecessary.

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My only justification for creating the most accurate ammo possible is to remove any doubt that the nut behind the trigger is responsible for misses

Is it worth it to do (____)

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Depends, it can be but it can also be a waste of time.

What are your wants and needs, with what firearm?

I like it.

One thing I just thought about to add to the list is "crimp or no crimp". I've got chrono and accuracy data that I collected that settled the argument for me (at least with the one caliber and bullet I was using). Do we start a separate thread for each item on the list?

About all I do out of that list would be (dry) tumble my brass... simply because it looks better, not for anything ballistic. I am taking an interest in different primers, I've noted a few differences between some. As far as all that other stuff... I only have one rifle that might benefit from such time-consuming process, and I don't have that kind of time.

I also agree with toprudder... crimp or no crimp would be a good question... and 'if crimp, what kind?'