Kelbly's is amazing! I'm a member at their range, and they are just downright good people. Family folks willing to help a stranger. I was in need of a little help getting a chassis fit on a rifle. Not knowing the"level" of what went on behind the shop doors, i approached with no expectations. Not only was i greeted with enthusiasm, but they took a quick look at my issue and disappeared with my rifle. I quickly learned details of what went on there, and I'm certain he could see the light click on in my eyes. He offered me a tour of the shop (which i jumped at the opportunity) and he showed me every step start to finish! Anytime i had a question, the guy performing the operation was proud to take a moment and explain. I've got a woodworking background, so watching them transform chunks of steel into a finely machined work of art was VERY fascinating! After my tour, we we're met back at the front office with my newly fitted rifle to chassis. I was then told there was no charge for the help. I wasn't raised that way, and left double what i thought might cover it. Simply down to earth, absolute good people!

I love this. I love that someone is doing these tests, I love how "in the weeds" this is getting. I love the that he literally says the exact same thing I say after nearly every range trip... "I'm left with more questions than answers. " I always felt like an idiot because I'd follow the instructions, I'd do the tests the way they say, I'd base my load on that data, load 25 more that same way, go out the next day and shoot completely differently. I'd ask 5 different people and get 5 different answers. I'm left wondering what REALLY matters... you ask a bench rest guy and EVERYTHING matters... you ask an f class guy and they think the bench test guys go too far, but they also measure the volume of each case because they're convinced that matters. Then you hear prs shooters say they don't even do seating depth tests because it doesn't matter THAT much... what can anyone believe? I want to do these kinds of tests, but I don't have the time, money, or equipment to do them right. I will be following this series closely. I love the hard data. I love that you talk about things like "standard deviation" and "statistically significant" data. These are terms and methods used by the scientific community to figure out IF there was a change, but also how impactful or noticeable that change is, and if their distribution is reliable. I took a statistics class in college, and I learned how to calculate all of these, but I have since forgotten. I'd have to pull up a text book to refresh my memory on the details, but I remember the general concepts, and this research is directly in line with what I learned. Please keep going with the same attention to detail.

OK, I knew I didnt know anything...... this confirms it !

Hello from down in New Zealand. I've been watching your videos for a long time . . . . This one is among the most usefull and profound you've produced. Thank you!

Thank you for sharing Keith. I love the way you apply science to your testing and show the importance of statistical significance.

This is one of the very best Shooting / Loading videos ever produced. Pure science without bias toward any Caliber / Rifle Mfg./ or Bullet Mfg. Love this Thank You. Lenny

Thank you very much for this valuable research.

Thank you for sharing!! Also, thanks for detailed explanations about the testing format.

Things I can confidently take away from this video: your gun shoots very well Load development always reminds me of this quote: We have not succeeded in answering all our problems. The answers we have found only serve to raise a whole set of new questions. In some ways we feel we are as confused as ever, but we believe we are confused on a higher level and about more important things.

Fantastic video, greatly appreciate your efforts on this one and the great break down, even if there weren't any solid conclusions.

This is fantastic! It reminds me of my Ph.D. dissertation where the conclusion was (paraphrasing), "the math works, the process works, but it's just not efficient and no one knows why." Granted, that was for a couple electrochemical reactions to convert molecules from oxides to hydrides... but I totally feel the pain all over again of having more questions than answers.

Thank you. I’m relatively new to reloading. Knowing I’m not the only one trying to work this our help a lot.

No ads! What a legend :D Great video also!

Even when I don’t understand all of what you’re talking about I find it interesting and entertaining to watch. I do learn a lot though, and as a new precision shooter and one who’s reloading, thank you for doing things I would never even think of.

Always great content, thank you.

Awesome video, keith!

Thanks for sparing us the ads👊🏻

The more I learn, the better golf looks...............!

Great video - fun and interesting stuff!

Wow. Now we have to contend with Group Center Wander. 30 years as the nut behind the bolt and I was oblivious on a conscious level to this. Thank you for the time, money and effort you have spent on this test.

The key to load development is to not put too much emphasis on any one or two stats. That tiny group at 100 yds for 3 or 5 shots may not tell you much at distance. Thanks for taking us down the bunny hole with you Keith!

This has made the inconclusive seating depth test I did yesterday, more inconclusive haha. Joking - I really enjoy your content.

Thank you patrons!!! 🎉🎉

Great video. I’ve decided if you pick a good bullet with an appropriate powder you’ll be fine. With big enough groups things start to look a lot the same.

Great work! This is exactly why my 100 yard stuff is just to get some "maybe" loads. Then hit 600 for testing/fine tuning and eventually 1k tuning. What's really fun is sometimes my 600 best load and my 1000 best load aren't the same... How fun is that? Ultimately there is always just a bit of voodoo involved due to how many variables exist. Love watching the channel and seeing the science behind the magic.

Mean point of impact standard deviation is equal to the true dispersion divided by the square root of the number of shots. Since dispersion is the result of random processes, there’s nothing you can do to make the mean point of impact “more stable” except make the groups smaller..

Really outstanding testing there. I’m glad that somebody out there is thinking about group size and statistical significance. These days I don’t worry too much about seating depth as long as I’m shooting hybrid bullets. The main thing I do when reloading is make sure that the seating depth is as consistent as I can make it. My personal thought is that variability in the seating depth is way more significant than the actual depth itself.

Absolutely fantastic.

Without reinventing the wheel simple ram and cram work best for me. My experience was best to neck size only to max .001-.002 tension, load longer than the lands, then single feed in my 700. The caming of the bolt insures the case shoulder is against the chamber datum line case to case same, and the bullet "jump" is zero insuring exact same cartridge to cartridge without calculating throat erosion. Works for me and simple consistency...

So we discovered consistency matters most.

Great video, thank you Sir👍

More questions than answers usually means that you’re on the right track. The world is vast and infintismally small. Isn’t that great? Excellent video.

New subscriber. all the best from the UK

Great video. Thanks for explaining and proving the sample size that we need to be working with.

Great video! The number one most important thing to me when im doing seating tests is windflags. To me its pointless without.

I think you just validated something Hornady presented data and outside expert commentary on a few months ago. There's SO much we shooters 'know' that's just not so. OTOH, confidence materially and demonstrably improves performance, so one doesn't go trying to undermine oneself.

Thanks!

I guess the big question is; at what point do you stop splitting hairs? My answer would be, when you stop having fun. I love seeing the research because someone else is putting in the work. Great analysis, and I concur with your conclutions.

good explanation! somehow I missed your genial diagram with grouped box plot with ED SD and average values for each depth.

Biggest thing you’d didn’t mention that you have to consider is variances in case head space and case trimming which has a large impact on seating depth depending on the dies and case trimmer you use.

Okay, let's do this. Subscribed, bell rang, commented, liked, upvoted, shared .... may the algorithm gods smile favorably upon your channel.

The numbers are science if you ask me. They are controlled enough for me to find the testing valid. The only question is the question of repeatability. I assume that if we were to do this experiment again a second time, (which I would love for research purposes of course) that the small sample size groups would have completely different results because of the small sample size variability. I also believe that the large 33 shot groups would probably be quite similar.

Nice. As a scientist often employing statistical analysis on small and large data sizes I love this particularly your statement about your lack of significance in proving a difference from the null hypothesis. One might assume its for a lack of power or data size but perhaps not as the distribution shapes in 2d are quite different. Thank you. Your experiment here seems to assume that for each loading you actually achieved the same seating depth for each round. If you could have I'll bet there is some movement there and differences in variation vs your different target depths, meaning I'd expect greater variation with deeper seating depth. . I'll also bet on variation in seating neck tension?. How precise are your depth measurements and inside neck diameter? With different distribution shapes, standard statistical models may struggle. If you had the data of high precision seating depth one could plot vector values angle and distance from center vs that. Probably out of scope though.

Yep, as per Gödel's theorem there are true statements in the realoading theory which cannot be proved.

Outstanding video! Thank you sir! Liked & Sub'd.

I recently was testing the speers grand slam in my hunting rifle, the speers data listed a seating depth of 2.685, i could not get these to group, we're talking 3-4 inches at hundred yards. In a last dig effort i measured these bullets to my barrels lands, which was 2.848, this was such a huge jump that i loaded them to 2.775 and got them to group sub MOA with two different powders. Seating depth plays a huge roll. IMO

If you could have seen the smile on my face when you said, "We are closer to proving they are all the same, not different". Nature is perfect, nothing else. Some think 1ft is close, some 0.25", others won't settle for less than 0.001" and most who state, 0.0004" might be accurate in what something should be, but they have no clue how to measure, (guarantee) it. Or worse, you see a shaky table with a Starrett Vernier Height Gage. Tolerance is as misunderstood as monetary policy. In other words, everyone is an expert, (at spitting the rhetoric), until it isn't. (Argentina, Rome, Japan). Much respect for what you do, so refreshing to see people taking things to the nth degree. "If you torture the data long enough, it will confess", but unicorns still don't exist. Try, test, break and prove. Don't vehemently spit rhetoric from other sources. If I haven't done it, tried it, lived it, built it, broke it, tested it, everything else is hearsay, rhetoric or logical fallacy. TEST, TEST, TEST, question the data and RETEST, RETEST, RETEST. The goal of science is not to find a final answer, but to ask better questions. long time subscriber... Great content, please keep it up. Will try to be better on the likes, sorry. (.284 fan, 7mm-08 and 280AI)

Having shot silhouette competition for years I've found that some cases will not shoot. Therefore after I have prepped all of my cases I go to the range and any round that shoots outside of my group goes into my junk brass. I've shot many 1/16 inch groups following this procedure. I feel the brass is the most important part of the reloading procedure.

I am a scientist and appreciate your hypothesis and the fact instead of definitive answers you created more questions. Isn't science great? LOL, good job

Another variable people often don't think about when measuring group size/mean radius from the center of the bullseye or the corner of the square for this instance is that I can almost guarantee the crosshairs were not in the position you are measuring from when the shot broke for every single shot. As steady as you can hold the crosshairs on center, there is going to also be variance from that which is typically not accounted for.

What video is the one where you mention diferent bullet profiles and the seating dept that they favor?

It is a constant challenge trying to be better especially when you almost have it down. Nothing seems to be a 100% constant in reloading. Most everything can change group size and when you change one thing it is more than one thing. Bullet length effects case capacity as well as bullet jump or jammed in the lands. Have fun to all there are always more questions than answers. It's always fun seeing what others are trying and what works for them.

Crimp pressure also!

I miss the Biden Harris ads that usually bracket my favorite firearms KZfaqrs. I do love irony.

Nice video and you confused me. ?what would happen if you shoot a 33 round control group of factory match to set the base numbers? Would that be relevant or a waste?

The nearest thing too factual testing we have is from hornady but they’re obviously using Hornady brass and bullets. I know from experience that the components aren’t precise enough too even show a difference in small adjustments too the load. I want too see Capstone or Berger do some large sample size testing.

Now to perform the same test at 1,000yds. I really liked this video. I did a similar test with only 2 loads at 1,000yds and 20 rounds of each load with my 223 and the smallest 100yd group was not the winner for sure.

I have a Ruger77 MkII in 300WM. At best with factory ammo 2 MOA maybe a tad under. I loaded 20 rounds Starting at factory dimensions and did 5 groups .005" steps and found the sweet spot thankfully in my third group a full .015" longer than factory. I'll take that experience to the bank as the simple hunter that I am.

Even though no actual jump numbers were given in this video, it sounds very similar to Mark Gordon’s study from a few years ago written about on the Precision Rifle Blog. It seems to confirm that the micro results of best 3 and 5 shot groups don’t match the macro results of consistency of group size and POI over a larger sample size. Typically a bullet jump of .050 - 0.100 yields better large sample consistency even though .010-.030 might give you tinier 5 shot groups.

Keith , great video I’m a friend of Michael’s who you mentioned. I don’t understand why you say the group center shifted , I think it is much more sensible to calculate the relative center for each load then take all data from there it just streamlines the result. If you only look at it that way I think the data will show the statistical samples are indistinguishable.

Yes it does, if you don’t have a barrel weight/length harmonics adjustment. Both is best.

Also, bullets are different and will shoot distinct patterns depending on how they are made. Lead tamp just a liftle off center and you will get 3&2 groups. Boatail off a bit. 4&1 groups. Point being, you are holding the bullets as a known constant when they are not, especially at the differences you are trying to detect.

First of all I’m a firm believer in seating depth doesn’t matter, but only if you are using hybrids and tangent style projectiles. Things to remember. He was using hybrid projectiles. Which Litz has stated in his science is not affected by seating depth as much as secant/vld profile projectiles.

How much did air temp change during your test,barometric pressure, your load, powder type, etc… there are many things that are controlled but are they? Was there a small breeze? Did one bullet have a small deformity? The brass, was it new or how many firings? What primer type? Seating depth of primers? Did you clean your barrel between each firing? I know you know all of this? I’m quite impressed with your test and attention to detail, as well as your analysis of data seems on point. But in theory you’d have to repeat the whole test 30 plus times which is impossible under the same conditions.

Run the median values(median radius and median group sizes and appropriate SD and ES)and see if the story changes... and an ANOVA test. In all my research lab experience, when sample sizes were low, median values were the way to go because they are resistant to outliers, good and bad ones. Anyway you slice it 33 holes is a small sample size out of the total "population". Not a dig at you, it's more than most people do, and reality dictates that unless you have someone feeding you time, money, components, and barrels, getting legitimate large sample size of everything you want to test is not even close to practical. Anyway, try the medians and anova on what you already have, thanks for the info and keep up the good work.

Bullet seating depth and free bore seem to be the reason why one another are hot topics. If you get the free bore you desire at that point should it just really be at the mercy of powder primer with a constant being the published seating for the load in the reloaded bible?

Science entirely does work by proving or disproving a hypothesis, but it has to be done in a way that removes tester/test bias and confounding variance

A recommendation: consider performing a 2-way ANOVA since there are factors that could affect another factor, ie: barrel temperature with x.

I was thinking more about this overnight. I wonder…we know the Hybrid is a relatively tolerant bullet. It’s why we like it. However, how does barrel wear play into it? How about bullet variance? Lot to lot variance? With so many variables, could regression analysis be helpful in determining where to place our focus?

More evidence tuners dont really work, especially when people only shoot 2-3 shot groups, great video 👍

I'm not by any means, an F-class shooter, but I would venture to think that bullet jump plays a roll in how concentric the bullet is going to be when it hits the rifle lands. The farther the jump, the more the variance. When I reload, I measure and weight every component and group them to the least variance. Also I seat bullet to slightly touch the lands to eliminate bullet jump. That has given me great results.

Great video - I am curious as to what made you pick setting 3 in the first instance before this test...what did you see that made you go setting 3 direction?

Where did you get the barrel temperature stickers? I have some that I got from McMaster, but they don't stick as well as they could on a cylinder.

This test does anecdotally support the general belief in High Power / Service Rifle circles where it is accepted that the highest scoring loads often are not the ones with the smallest SD. The load that scores best, scores best. To confound predictions even more, the case can be made that some fractional amount of intrinsic error is not always a bad thing. It would seem that at some point we get within the margin of error and start chasing results that we cannot guarantee given the variables that we cannot control. Worse yet, your ammo may get so accurate that you lose the margin of forgiveness that was benefitting you. Statistically, intrinsic error in the cone of fire can help you as often as it hurts you. Sounds crazy, but here's a great video from Konrad (HP legend) showing just that: kzfaq.info/get/bejne/rah5n8yY35eynIk.htmlsi=E74e0MVzEKvZKmt7

Hey Keith, quick question: how "far apart" were the 3 different seating depths you selected for your testing? At 5:25 you asked if you "can do seating depth testing in much bigger increments" and I'm just curious what the total delta CBTO (in inches) was for your 3 loads?

Id imagine its possible that the data could be more determinant at a farther range? Say, 600 yards? I only ask that because im finding that developing a round to group, say, 1" at 100, can be done easily, but that rounds performance at 500 yards could be the exact opposite. Basically just thinking outloud here. I will add for context the reason i ask that question is because im finding that a projectiles bc under 200 yards, for hunting, is negligible based upon caliber. I just wonder if this test was conducted at 600 or 700 yards if the data would show something different? Thank you for what you did to make this video. I really appreciate it

Great work. I wonder: maybe all the analysis is not only inconclusive..but might also be a net negative? Are there any F-Class shooter who just load and shoot? The hypothesis would be over analysis creates doubt and, therefore anxiety/stress..leading to poor results. The idea being a relaxed mind and body...lead to better results? I shoot a monthly 25 yard open sight match with .22lr Over the years I have found the "harder" I aim...the more pre-shot thinking I do...the worse the result. I do best when I intuitively find my aim point/hold and squeeze the trigger with little to no thought. Shooting 25 shots will take less than 3 mintues...some times faster Thoughts?

More questions than answers........the same result i get any time i test. Good video

OCW method is the key! Get the charge weight perfected and then the seating depth can be locked in. Easy peasy. :)

Where can I get that hoodie?

what if you want to download your bullets. So that instead of achieving 3200fps you get 2500fps? how would you get that to shoot accurate?

Just for curiosities sake did you collect velocity data during this test? It might be interesting to see if there are any correlations there. It would also be helpful to know how much the seating depth varied by for each set. As at this point it seems reasonable to think that moving the seating depth 0.001" for each test would show smaller differences than moving it 0.010". I think it would be more helpful to first prove that seating depth makes a difference then move on from there.

30-shot groups have a variability of 7-10%, so I believe that there is likely no difference in the three loads tested. I have seen similar results to yours in my own tests

Could the results be effected by moving the gun in the rest to hit the squares? The test may be verifying how the gun reacts to changing point of aim in the rest. Along with all those other variables.

Hi Keith, Love you video and ground mat. Where's the mat from please? Cheers, LD girl from Sydney OZ

The only thing that is proved over and over again in my mind all these years, is that you need far more shoots to determine your theories than we thought. Whit 3 shoot groups or 10 shoot groups you can not know...

That's very interesting information. Now, I'm wondering about all my rifles as I've picked them all based on the smallest group size. Fortunately, my main interest is about being the most efficient, effective, and precise hunter I can be. Being that you are one of the best at explaining the technical in a way that's easily understood, do you think you can do a video on how to properly calculate a bullets BC? I often really wonder about some of the BC data provided by various manufacturers.

I've been reloading since 1957 and every time I think I know how some load/rifle combo works, something happens to prove I know nothing!? Ahh... well, the fun is in the journey. Thanks for not posing a conclusion that may or may not be statistically accurate.

A serious question from a beginning precision shooter. “The first shot” or cold bore shot. Is the difference the heat of the barrel or a harmonic resonance? If its harmonics, has anyone tried to create that same resonance artificially in the barrel prior to the first cold bore shot? Or, heat the barrel prior to the first shot?

It seems the more we dig into the established norms of load development the more we find a lot of what we've be taught is important makes no statistically significant difference in group size. Let's face it, a lot of load development was pioneered by people with borderline or actual OCD and the placebo effect is a very real phenomenon. If you believe it works, you may actually shoot better because you are more confident and more calm.

Seems like you have to shoot this indoors, with a fixed mount and maybe look at barrel temp effects at the same time.

I bet it comes down to the guy shooting the rifle over a very expansive shooting spree at one time. Shooters fatigue is real, and bet that it has more to play in this outcome than anything. I am a hunter not a benchrest guy so I'll happily take group 1 forever.

I still think your personal biases are clouding your judgment. This video just proved to me that seating depth really doesn't matter that much. It certainly can make some difference with large changes but I think those .005 changes really don't make much difference

I may have missed it but what were the jumps in seating depth for the test? Were they all in a node, same point of impact?

👍👍👍

"does pressure change bullet velocity" = duh. it all comes down to tuning your load to you barrel harmonics for consistency in as many areas as possible

Full Factorial DOE... that is a lot of shooting.

For me, the question becomes 'how much is enough'? This rabbit hole goes deep! LOL~ Thanks!! EDIT: Also for me, LOW single digit SD and ES numbers are an absolute must. I'm no statistician but it seems self evident that the more consistent a load it, the more likely it would be to respond to tweeking seating depth.

The seater didnt change/ not the press , the bullet does bullets i choose to work good hunting are giving 11.000 different oal ( plastic tip usually) try make oth variables consistent.use flat but bullets alot. Xtreme bc wont matter me maybe once , twice if i missed in my life time. I DONT KNOW WHERE IM MISSING SOMTHING IMPORTANT.🥂

Seating depth affects pressure curve and pressure curve affects barrel harmonics. It would seem that seating depth should, by reason, affect group sizes. I think it would be far more apparent on a factory rifle than a custom build with high end components. Factory rifles are far less forgiving. I have found much greater differences created by seating depth changes in a factory rifle so that is the basis for my theory. That being said... the mystery still lives on.