323: Bullet Stability with Jeff Siewert
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- Опубліковано 20 гру 2024
- Welcome to the Ron Spomer Outdoors Podcast! In this episode, I interview Jeff Siewert about bullet stability and his book Ammunition Demystified.
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Who is Ron Spomer
For 44 years I’ve had the good fortune to photograph and write about my passion - the outdoor life. Wild creatures and wild places have always stirred me - from the first flushing pheasant that frightened me out of my socks in grandpa’s cornfield to the last whitetail that dismissed me with a wag of its tail. In my attempts to connect with this natural wonder, to become an integral part of our ecosystem and capture a bit of its mystery, I’ve photographed, hiked, hunted, birded, and fished across much of this planet. I've seen the beauty that everyone should see, survived adventures that everyone should experience. I may not have climbed the highest mountains, canoed the wildest rivers, caught the largest fish or shot the biggest bucks, but I’ve tried. Perhaps you have, too. And that’s the essential thing. Being out there, an active participant in our outdoor world.
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Disclaimer
All loading, handloading, gunsmithing, shooting and associated activities and demonstrations depicted in our videos are conducted by trained, certified, professional gun handlers, instructors, and shooters for instructional and entertainment purposes only with emphasis on safety and responsible gun handling. Always check at least 3 industry handloading manuals for handloading data, 2 or 3 online ballistic calculators for ballistic data. Do not modify any cartridge or firearm beyond what the manufacturer recommends. Do not attempt to duplicate, mimic, or replicate anything you see in our videos. Firearms, ammunition, and constituent parts can be extremely dangerous if not used safely.
Now I am going to have to buy his book. This is the sort of information I have been interested in for decades.
Jeff gets much more in-depth on the Hornady podcast in several episodes. Worth a listen!
A very intelligent gentleman trying to dumb technical information for us not so smart folks. I enjoyed it tremedously. Thank you sir.
Having heard Jeff speak on other podcasts, it speaks volumes to his expertise knowing which approach to take educating others on the subject matter. He really dumbed it down well for us.
Jeff is a treasure! Thanks for having him on. I bought his book on Amazon, hopefully you can still find it there.
Jeff Siewert was my favorite guest you have had on your show to date. I wish you would have asked him about the various effects of different types of rifling. I have found polygonal rifling to be more accurate with higher velocities but my sample size is small. If there is indeed a benefit, it would be nice to promote the idea so that more manufacturers would produce them. Today, they are difficult to find outside of HK, FX, and Glock products.
Good info, Ron... keep it coming. Just ordered Jeff's book for another reference even though I've taught physics, dynamics, etc., and have been studying ballistics, internal and external for most of my life our of pure curiosity. Tiny jacket thickness variances will also cause an imbalance in any bullet and this imbalance will be worse with higher RPM's just like a tire that is out of balance won't be a problem in town, but will on the highway. Not an issue as Jeff stated with factory guns and ammo with good quality ammo, or with monolithic projectiles that have no real potential for imbalance. Every shooter should take the time to learn about ballistics... real ballistics, not the old wives tales we all learned at hunting camp. When we talk to our non-gunning neighbors we should know our stuff, regardless of where the conversation heads regarding firearms.
Ive heard jeff speak a few times and its always a pleasure. He knows his stuff and what terms to use depending on audience. I think it's about time i ordered the book
Nice to hear an engineer's points👍
Great podcast! Good questions, detailed answers.
Holy cow! Wow interesting but I think I lost him in the moment! 😂😂 That is so complex but I got the jest of it. Keep it coming Ron!
Ron did a good job at making sure Jeff stayed within the limits of the audiencess' understanding.
He tried and did do a pretty good job of it but it was an uphill battle, Jeff just doesn't keep in mind the audience aren't scientists!
I just ordered his book from Amazon, I'm sure it will be money well spent.
Hi Ron,
I once cc measured and batched my brand new Lapua brass. Waste of time with new but after a few competition days the internal volumes can vary from material flowing under pressure. The walls of the case and shoulders tend to increase thickness. This is why the cases tend to fail above the belt line regardless of type. Loving the deep dive into proper ballistics!! Don't compete any more. 4 nights a week loading and tuning 1 day a week comp for many years no time these days.
I didn't hear you mention bullet to lands distance or "Jump"?? It has a large affect on precision and accuracy. Looking for my old notes and data to share. Standard deviation is proof. 13f/s and group size was good enough for scores of 100 in Open Fclass, pity the muppet behind it wasn't most of the time😜 Wind can make all that work feel like a waste of time!!
Thanks Again,
Adam
I'm an engineer so I understand the terms he's using but most people are confused as hell right now. Getting a clear explanation from this guy is like pulling teeth from and angry crocodile, holy crap!
I need to re-watch a few times 😆
That was a great conversation for the average Hunter that he don’t have to worry about some of that bench rest target shooting those guys do
Very interesting...!!👌
Wow, great video. Eye opening information
Good stuff
In short that was brilliant
true velocity composite ammo!
So, here's a question. Do people still do barrel tuning, to increase accuracy?
lol, thats what shooting different ammo in your gun is. like doing a ladder, but brands instead
@@Sageofthe16 Barrel tuning is about controlling barrel vibration/harmonics/timing.
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Hornady warns against using their Superperformance loads in auto-loading rifles because the powder blend they use generally produce higher pressures farther than the barrel. This means the gasses are at a higher pressure at the gas port.
It depends where the gas port is located , like the M 1 the gas port is close to the end ( muzzle ) of the barrel so it requires a medium burn rate powder like 4895 , 4064 or 3031 . If the gas port was located mid way you could use a slower powder .
The way I understand it, a bullet sent from a rifle with a right-hand twist encountering a wind from the right will jump. It stands to reason that if the same bullet encounters a wind from the left, there would be a corresponding dive. Can you confirm this?
Provided it’s fired from a barrel with right hand twist, true.
A second interview with Jeff I have heard.
One thing for sure , there are so many variables. What we get is a based on a guess.
Have the designers machined the imperfections into a childs top model to identify stability problems? I guess the Rpm's would replicate a sub sonic load
A gyroscope like a child's top stabilizes best when it front weighted., imo
So many silly questions
In this video, at 1:49:00, Bryan Litz confirmed what Jeff said, i. e., spinning a bullet faster than it needs for gyroscopic stability exacerbates wobble, and hence accuracy. If all bullets were manufactured perfectly, and left the muzzle uncompromised by obturation and engraving, they wouldn’t wobble, so it wouldn’t matter how fast they were spinning, so long as the jacket could hold up to the centrifugal force.
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Nicely summed up, Scott. A perfectly balanced bullet cannot be "over-stabilized."
@@RonSpomerOutdoors Manufacturers make recommendations so people don’t complain about their products. Their minimum twist for a given bullet is going to be fast enough for the bullet to remain stable through the transonic zone. Hunters don’t care about that. The latest long, heavy ELD-M might shoot fine at hunting ranges in a standard twist barrel. The ELD-M is a good hunting bullet because it grenades inside the animal. The more lead, the more penetration and shrapnel. If you find you need a faster twist to shoot them, it’s worthwhile to rebarrel.
I wonder why he recommended shooting three 5-shot groups and averaging them vs. shooting one 15-shot group. Did he mean shoot 5 then adjust, shoot another 5 adjust, and finally another 5?
Perhaps to let rifle cool, to add in cold barrel shots to the average, factor in different weather/atmospheric conditions on different days, temps, etc.
Don’t adjust after each 5 shot group, the average impact point walks around with every group. Shoot 3 five shot groups & average the center of impact for all three groups.
@@jeffsiewert1258It would be challenging to shoot for three days just to sight in a rifle. I have never shot three shot groups for this very reason. I usually shoot ten shots to get a better average. I guess I need to shoot another 5. I always let the barrel cool between shots too.
Having a computer track it over a few days sure would be nice.
@@jeffsiewert1258 Why would the impact point walk around with every group? I know the parallax error from the optic would cause this, but I understand how to center my eye to prevent it. Other than that, other than various wind speeds, there isn't anything that should change from one group to the next.
It’s an artifact of the sampling statistics, every time you fire a group, you’re “sampling” the ammo. The average impact point “walks” based on the true dispersion divided by the square root of the number of shots fired. That’s why you should fire larger groups when firing for zero.
My dad said he qualified at 200 yards , I wonder if the 3006 is yawing at 100 yd.
The levels of yaw by 100 yards is typically only a degree or two. Too small to measure on. a target. Believe it or not, this was a issue for armies, especially during WWI because any yaw would reduce bullet penetration in sand bags, and penetrating sand bags were a big deal. They measured average penetration at different distances.
I could see this ballistician on the witness stand, in a murder trial, explaining ballistics to a Jury as a expert witness. I wonder if that has been the case? No pun intended.
Timestamps, please. You used to have them. I sadly don't have time to listen to the whole thing.
Don’t build a 270 with a 1:7.5 twist rate so it can shoot 175 grain bullets, and expect it to shoot 130 grain bullets accurately.
I don't know, Scott. I have a 22-25- AI built to stabilize 75-gr. and it shoots 45- and 40-grain MOA
@@RonSpomerOutdoors Jeff said it, not me.
Many Bubba's out here You fella" get off your high horse Ys Fudds
🕵️♂️ Ok, as an Engineer, I have a problem with what Jeff said! "Trusting the Software" - without understanding the limitations of the software and it's formulas - is not a good idea! NO GOOD ENGINEER DOES THIS!!! 😬 Why? Because, "Mathematical Models" often make "Assumptions"/"Generalizations" that aren't always correct to every specific case! ☹ And, in the case of Correlation Coefficients - or R^2 - It Has Several Limitations!: 1.) It cannot determine the non-linear relationships between the variables (i.e. Not every relationship is linear or directly correlated.). 2) It does not distinguish between dependent and independent variables (i.e. What caused the problem and to what extent?). For example, does a different lot of the same type of powder generate the same amount of energy or velocity every time? No, it is not a constant! So, making the "assumption" that it does in a mathematical formula would create (introduce) an unnecessary error in the data results! Thus, if we have a flyer, Why was it caused? And, How does that flyer skew or bias the data? And, What is the "Confidence Interval" that the data is correct? Their are two schools of thought - both with obvious limitations! The First is the Engineer, who always wants more data. But, as you can see by this example, the "solution" to getting it isn't always practical! Shooting 15 shots with a box of 20 cartridges isn't something most of us aren't going to do - especially if we have both a deer and elk tag in our pocket and we are hunting in Grizzly County! Would you want only 5 shells to "solve" at least 3 different problems? 🐻 Thus, Jeff's "Solution" doesn't take into account "Other Variables" (Jeff has his "blinders" on and can't see the bigger picture here - or obvious flaws in his logic - because he is thinking "inside the box" and not taking into account "outside variables".)! Thus, a pack of Wolves 🐺 may eat Jeff, if he goes into the back country with only 5 shells (Like alot of Engineers, Jeff can't see the Forest through the Trees - too focused on the small/fine details to see or account for the bigger picture/problem)! 😳 Conversely, other experienced shooter's (like an Eric Cortina) will talk about zeroing your rifle with one shot! 😂 But, is that really accurate, according to Jeff? NO (Me either - because it's not mathematically correct)! 😏 Thus, the "Truth" lies somewhere in the middle (both are wrong with their "logic") - as to how much data is enough, for a given sample size (from a statistical prospective, at least 10% minimum is a typical "rule of thumb")! But, I will save the rest of my comments for another post! 🤣
So i fed my family for 40+ years and helped my kids get thru college as a ballistics engineer. If you think I’m wrong, you’re entitled to your opinion.
🤣 Tell that to the Grizzly Bear or Pack of Wolves, when you run out of shells!.😱 5 Bullets to fill 2 tags and fend off predators isn't going to be enough! I Bet Eric Cortina Thinks He Is Right Too? Well, simply put, you both can't be right when you are saying the exact opposite things! But, You Both Are Wrong, If You Actually Read What I've Written! 😜 Have a Nice Day! 🤠
Nothing is stopping you from buying another box of ammo, other than getting lost in the data and irrelevant scenarios.
🤠 The Lamar Valley Wolf Pack has 175 Wolves and does occasionally come out of the park to where I hunt! So, you aren't fighting them off with 5 shells or 25 shells! Being a hunter where I live requires that you know more than just about ballistics! 😉 However, I have been an Engineer for just about as long, graduated from one of the most prestigious universities in the country, married a High School and College Valedictorian, and Have a Child Just Finishing Medical School! So, I am no dummy either! But, all the pieces of paper on the wall do you no good, if you don't have any common sense! 😂
😂 Anyone going into the back country of the Rocky Mountains, with only 5 shells, better be saving the last one for themselves! 😵 If you listen to any of Randy Selby's videos, you'll quickly realize that you may shoot an Elk and see both Bears and Wolves standing over your kill before you get to it! 😯Then, you may run into some armed hostile person, trying to claim your trophy! Multiple times I have been packing out Elk Quarters at night, when a Mountain Lion has stood over my kill and followed me out of the mountains!😬 Then, if you get hurt and need to be rescued, those "additional shells" will help the Search and Rescue Find You! 🕵️♂️ So, anyone going into the back country With Only 5 shells is a Fool! 🤪 But, I am no ordinary "Weekend Warrior", I am Ronbo (Montana Mountain Man)! 💪
Fa fa fa .
You a fudd snide pokin fun at bubbas