Keith’s seating depth video
- Thread starter davidjoe
- Start date
Dave:
{{{{ Updated 6/14/24!!! After researching tagging of powder, the 1st 3 lines are a false statement!!! DuPont maybe some other USA manufactures HAD markers for identifying their powders!!! I use to remove these long time ago!!! Bill Clinton tried tagging powders but the NRA shot it down in the courts for violating the 2nd AM!!! I MISSED THIS EVENT AT THE TIME!! This forced the US into not signing the ICC new purposed law and banned US manufacturers from tagging their own powders!!!
As a scientist, I have to document any corrections to the original report or statement!!! }}}}
All powders have inert markers that don't burn!!! It is there for 2 reasons:
1. Powder ID (Manufacturer, and powder type)!!!
2. Forensics in crimes!!!
Yes, some powder can survive!!
I've done the white sheet tests!!! Very few collected particles burned!!! The ones that did, were imperfections of the homogenous mix!! A small lump of dry ingredient when run through the extruder having higher density and harder than the rest of the extrusions!! They took more heat to burn than powder out of the can!!!
A little note on those particles expelled from the muzzle!!! Use Newton's 2nd law!!! Without mass, there can not be pressure!!! What drives that bullet down the barrel is high pressure (high density mass) gas pushing on that bullet base profile!!!
Infact, the mass of the unburnt (but still burning column behind the bullet) powder and the gas density are so dense, they act as a fluid!!! With the extreme heat, that fluid is actually plasma (high energy fluid)!! Rocket science!!! Gases are compressible, Liquids are slightly compressible!!! Hydraulics is more power than pneumatic!! This is the fundamentals of thermodynamic which I truly enjoyed taking for my physics degree!!!
I have read and studied internal ballistic reports from the various military labs and testing field facilities from the 60s - 80s!!! The proof is in the barrel!!! Most barrels will show a pressure washer region where the fluids past by (High transport velocity)!! When the volume increases enough behind the moving bullet, the density is reduced!! At that point, it acts as a high density gas again and releases heat and lightly scotches the barrel from that point to the muzzle!! It also loses the ability to transport, leaving behind burnt powder residue!! The phase change (gas to liquid, liquid back to gas) is called Adiabatic and Diabatic processes!!!
Just because we can not see it, like air, doesn't mean that we can't measure or test!! There is more than just gas pressure in this combustion engine we call firearms!!!! Energy, Power, and Work to name a few!!! That Energy (heat is measured with a thermometer) is conserved!!! Using a bomb caloriemeter, the total, and sums of the heat can be measured!!! The 1st law of Thermodynamic (Conservation of HEAT which is energy)!!!
Aim small, hit BIG!!!
BILL
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TylerFromMS
Gold $$ Contributor
Sir, you’ve got some awesome info and I love the deep knowledge. But please, ignore the exclamation mark on your keyboard. Just pry that sucker off.
Statistics is gathered data from the past. In higher level mathematics, you use statistic to predict the future which is called PROBABILITY. Probability mathematics may make the stats valid or invalid information.
In my experience accepting an assertion as "universally true" can be unwise. There are just too many variables in the ammo, equipment, testing condition, and shooters to make such claims.
Like everyone else, I am always looking for an opportunity to improve performance. If I read something that sound sensible, logically, and being used by knowledgeable shooters, I might be interested. What I do, is test the assertion to determine if produces better results for me, with my equipment and for my shooting discipline.
With regards to seating depth, I think it can matter depending on the bullet and rifle. Sierra did a study on this many years ago and found that, in some bullet / rifle combos, seating well off the lands produced the best results. I found this to be true, especially with my favorite bullet, the Sierra 85 BTHP in the 243 Win. after testing in 4 different rifles. However, for example the Nosler 55 BT, I found that within reasonable limits, it made no significant difference that I could detect in 10 different 223 Rem bolt rifles relative varmint grade accuracy (in the 1/2 moa range).
The answer to the question he asked though, is universally true. Wind is a huge factor once you get to the point where gun, load and shooter can consistently shoot better than the condition mathematically allows. Without flags, we're guessing, wasting components and bbl life. Its really is that simple if we're talking serious accuracy. I think we can agree on that but I still hear a lot, how the wind doesn't move a bullet at 100 yada yada.
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Plumbing a ND electricity with you...
Lmfao
I'll clarify that these 15 particular cases only had two firings. Fire forming
and one seating test. I generally lube these break in cases, but I also use
no lube after the 4th firing, when enough carbon has been built up......
I'm thinking that with a lack of lube, these15 particular cases got a little
more neck tension, and maybe a more even burn in the boiler room.
Rounds are loaded for the repeat. Lab should give some good numbers.
However, if good, I'll log it for the future since these cases will never see
a second firing again. They will have changed, ever so slight......It never
ends !!
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I missed that part (wind), but absolutely agree with the effects of environment on dispersion. Mirage is also a huge issue at one of the clubs where I belong.
When doing load development, which I do not do a lot of anymore, I always pick a day with overcast skies, moderate temperatures, and no wind. This tends to minimize the effects of the environment, but I am not sure that it totally mitigates it.
Dave: Please re-read my previous statement!! I had to make a correction!!!
I really don’t need a perfect day to test seating depth, just not horrible. I also need to know how the load will perform in real world conditions. I don’t require a huge sample size just enough to find the edges of the window, and confirm.
I use a couple flags at my range to note the conditions but for those that don’t and there are plenty of great shooters ( far beyond me ) that simply use a round robin firing sequence to nullify the conditions and determine a seating window without burning extra rounds.
Pull into Deep Creek during a Friday morning 1K tuning session and you won’t find a sea of flags , maybe one pin wheel up front and ribbons down range, but you will see eye opening results.
Jim
I use a couple flags at my range to note the conditions but for those that don’t and there are plenty of great shooters ( far beyond me ) that simply use a round robin firing sequence to nullify the conditions and determine a seating window without burning extra rounds.
Pull into Deep Creek during a Friday morning 1K tuning session and you won’t find a sea of flags , maybe one pin wheel up front and ribbons down range, but you will see eye opening results.
Jim
jackieschmidt
Gold $$ Contributor
I guess it depends on the accuracy and precision requirements of the Discipline you are involved in.
If you are attempting to achieve the “sub .200 agging capability” with a 100/200 yard Benchrest Rifle, shooting without flags is an exercise in futility.
I never shoot without my flags set exactly the same way as in a Match.
If you are attempting to achieve the “sub .200 agging capability” with a 100/200 yard Benchrest Rifle, shooting without flags is an exercise in futility.
I never shoot without my flags set exactly the same way as in a Match.
I seriously don't know what this is or means. Can you please explain what it is or how shooting round robin nullifies conditions? I've always felt that unless you can literally see the wind by some means, we can't possibly know what it's doing when we pull the trigger. Now afterward, we get some idea...if the shot goes where it should based solely on what we think the predominant condition is. Yes sure, good conditions happen that can and do produce small groups but I've also seen what a single flag switch out of five at only 100 yards can do to a shot...many times, unfortunately.
If you have an idea what the wind is doing and a shot goes out, but it's where it should be out in a given condition, I get that. It's part of shooting and reading groups with accurate rifles. But yes, it blows my mind that anyone shoots without flags, ever. That's because I've seen how much it matters. It matters in short range and it matters even way, way more as distance increases.
I've shot plenty without them out but I stopped for the most part a long time ago. IMHO, flags are the single most important piece of equipment at your disposal. We don't get to shoot matches in perfect conditions, if such a thing even exists. Lol! I strongly believe in getting very intimately familiar with some sort of flags, for any distance or discipline that allows them.
That's all. I'll sit back and listen to what you and others have to say. TIA.
I’m not trying to convince anyone of anything, I’m just sharing some information. Guys can take it as posted or not, I really don’t care one way of the other, a guy only needs to look at the results to see 1k groups in the 1’s and 2’s to wonder how’d they do that ?
As I posted I use flags at my 500 yard range but at 1 k you really can’t see flags way down range anyways so we mostly use RR.
When using a RR foremat each series of rounds share a condition, it’s a long range thing that for the most part works pretty well. Some days the weather is just too bad to get good data other days it’s pretty obvious which load is best.
Jim
As I posted I use flags at my 500 yard range but at 1 k you really can’t see flags way down range anyways so we mostly use RR.
When using a RR foremat each series of rounds share a condition, it’s a long range thing that for the most part works pretty well. Some days the weather is just too bad to get good data other days it’s pretty obvious which load is best.
Jim
This would've sufficed. Thanks
BoydAllen
Gold $$ Contributor
My good friend Wilbur Harris, who had a dry sense of humor, once observed something to the effect that it is interesting how putting out a few wind flags will make the wind start to blow. When I read of someone shooting on a day with no wind, I want to ask them if they own and regularly use a set of wind flags, or a rifle capable of agging a quarter inch at 100 yards under favorable conditions. My point is that how much the wind matters depends on the standard that you are trying to shoot to. If you are sighting in your .30-06 for deer hunting season, where the anticipated distance is under 200 yards, it hardly matters at all. But this is a discussion on a site named Accurate Shooter, where practices that produce the highest level of accuracy, are often the topic.
And this is would suffice also yet you continued on with a couple paragraphs.
It’s just a different game long range to short range.
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