BS-Neck tension

  • 1.1K Views
  • Last Post 24 August 2018
joeb33050 posted this 11 August 2018

 

Neck tension

 

There’s a test in TFS on this, John A. knows where. Neck tension affecting accuracy with < ~.75” groups may happen, but if so, the test results are well hidden.

 

Attached Files

Order By: Standard | Newest | Votes
joeb33050 posted this 24 August 2018

One purpose for the forum is provide for honest discussion and honest discussion will include disagreements from time to time. THAT IS OK. Different viewpoints and presenting your side of an issue if it includes presenting evidence is one way can learn and get better performance in our shooting.

If people discuss their favorite color, mine is blue, these are opinions.

Discussing the value of pi, the fact that velocity is a vector quantity, or the mating habits of blue whales serves no purpose. Opinions don't matter.

If we want to know if it is raining out, forming a committee to analyze and discuss the question is beaten by looking out the farking window.

Will bullets without  lube lead the barrel? Will they shoot accurately? 

Experiment, get some DATA, stop the nonsense!

 

Attached Files

  • Liked by
  • dbarron
John Alexander posted this 24 August 2018

At times this thread has gotten a bit over the line with unacceptable language. I will admit that I have been a bit frustrated at times and perhaps not as patient as I could have been.  Review of some principles may help future discussions.

 

One purpose for the forum is provide for honest discussion and honest discussion will include disagreements from time to time. THAT IS OK. Different viewpoints and presenting your side of an issue if it includes presenting evidence is one way can learn and get better performance in our shooting.

 

Having someone say they believe you are wrong is NOT a valid reason to either call names,  assign undesirable character traits to the other guy, or engage on aggressive or hostile speech. Write only what you would say in a face to face conversation when the other guy is Mike Tyson.  Read what he claims and take a deep breath or a break before answering.  Asking for his evidence is appropriate and so is mustering your argument and evidence and making your best case.  Keeping an open mind to the possibility that we could be wrong is sometimes hard to do but would improve the quality of our discussions.

 

Most members including most posters have indicated that they don’t like negative bickering so please dial it back a bit and keep this forum one we can all enjoy.

 

Thanks for your cooperation.

 

John

 

Attached Files

pat i. posted this 23 August 2018

"Greasers" I like that.

Attached Files

rfd123 posted this 23 August 2018

all my centerfire rifle cartridges are .45-70 and are amongst the quintessential original "straight" or "straight neck" cases.  they're loaded either pseudo fire formed (if new) with a straight mouth expanding die, or fire formed.  since the bullets are paper patched slicks, and the the chamber has no throat or leade (a classic 19th century style PPB chamber), the brass hardly gets "worked" and there is little to no neck tension.  i'll never go back to greasers.

 

http://www.BuffaloRifles.org

Attached Files

pat i. posted this 23 August 2018

O (don't mind me calling you O for short I hope) lube an the amount deserve a thread by itself. I think its important and interesting and wouldn't want to see the conversation lost in a thread about neck tension.

Attached Files

OU812 posted this 23 August 2018

Today my rifle shot best with all four lube grooves filled...and I thought less lube worked best smile

John you are a very smart man. I can see why you are president.

...

Attached Files

John Alexander posted this 22 August 2018

Question 2. Will the shot to shot variation in neck tension affect accuracy or muzzle velocity? This was the question I thought this thread was about because of the first two posts. This question has been answered and the answer is no, it doesn’t affect accuracy or muzzle velocity (at least until someone does the research to prove otherwise.) Then why do cartridges with a bullet that was harder to seat usually shoot out of the group? I've seen that quite a bit and remove those from the lot.

============

45.2.1

A bullet very hard to seat may be damaged or set back during seating. I would suggest that you examine your reloading methods and find out why you would have a bullet extremely hard to seat. Proper loading practices should eliminate such inconsistency.  I have never seen a systematic test that shows what you claim is really true but one very good one that shows that it isn’t true. Anecdotes like yours, if repeated often enough, sometimes become the conventional wisdom but that doesn’t make them true.

==========

Aside from Bottiger's excellent work I haven't seen you say exactly what he was doing for a proof.... can you quantify exactly what he did for all of us since you say it's true? Some proof, not speculation since you made a definitive statement on the matter?  

===========

I outlined what he did for proof in the fifth post in this thread.

I suggest you read that post and read the article. Then try to understand what you have read before asking more preachy and insulting questions. 

============

Rationalizing is not proof. If it is true, then a scientific or mathematical analysis should be shown .

“Rationalizing” doesn’t make any sense used in that sentence.  Please look the word up. Why are you accusing Bottiger of “speculation” and “rationalizing” any way when you haven’t read the article? 

Any shot to shot variation in the tiny force that neck tension could possibly provide will be overwhelmed by the much, much, larger variation in the force doing the pushing. As a math major might say "it is in the round off error and insignificant. 

As an engineer, I've found rounding gives an imprecise answer in real world situations and can cost big money to correct. Hard concrete numbers are hard to argue with...... Math has proofs for assumptions.... until proven with hard numbers, they are just assumptions.

Both of the sentences in that statement are incoherent and basically baloney.  But they do reveal a complete ignorance of the role in rounding off and respect for significant figures in engineering calculations. I don’t know what engineering school you went to, but you wouldn’t have made it through one of my classes without a better understanding of the proper use of rounding off and significant figures for displaying a realistic level of precision in engineering calculations.

John

 

 

Attached Files

  • Liked by
  • dbarron
Larry Gibson posted this 22 August 2018

Pat

 

Surely you jest, why show any now......we've not seen any proof from them for 13+ years that I recall......

LMG

 

Concealment is not cover.........

Attached Files

pat i. posted this 21 August 2018

Proof???? Did I hear someone mention proof???? What a novel idea! 

Attached Files

45 2.1 posted this 21 August 2018

Question 2. Will the shot to shot variation in neck tension affect accuracy or muzzle velocity? This was the question I thought this thread was about because of the first two posts. This question has been answered and the answer is no, it doesn’t affect accuracy or muzzle velocity. Then why do cartridges with a bullet that was harder to seat usually shoot out of the group? I've seen that quite a bit and remove those from the lot. it is only worth discussing because a lot of shooters still believe it is important, write that it is important, tell new shooters it is important, and spread information that has been disproven, thus almost certainly untrue because there are no known studies showing it might be true.

Aside from Bottiger's excellent work I haven't seen you say exactly what he was doing for a proof.... can you quantify exactly what he did for all of us since you say it's true? Some proof, not speculation since you made a definitive statement on the matter? which should have been enough to kill this particular Zombie you can easily reach the same conclusion by thinking about the relative magnitudes of the forces involved. Rationalizing is not proof. If it is true, then a scientific or mathematical analysis should be shown (this is what Joe is trying to do).

The forces required to seat a cast bullet without damage are in the range of near zero to maybe 50 to 70 pounds. The force needed to push it back out are almost certainly less -- maybe even zero as pointed out by Ken and others repeatedly. At any rate pretty small and totally insignificant compared to force of the expanding gas which for a 30 caliber bullet will be in the range of 1,500 pounds to 4,500 pounds depending on the load.

Any shot to shot variation in the tiny force that neck tension could possibly provide will be overwhelmed by the much much larger variation in the force doing the pushing. As a math major might say "it is in the round off error and insignificant. As an engineer, I've found rounding gives an imprecise answer in real world situations and can cost big money to correct. Hard concrete numbers are hard to argue with...... Math has proofs for assumptions.... until proven with hard numbers, they are just assumptions.

John

 

Attached Files

John Alexander posted this 21 August 2018

It is apparently impossible to keep the two types of questions about neck tension separated in this thread and because they are quite different questions the discussion degrades to mass confusion. I think we could confuse fewer shooters if we kept the two questions separated into two threads.

Question 1. What is the right neck tension for various situations? This is an important question. The wrong answer can lead to various ills as noted above plus; shaving lead, bending the bullet, upsetting the nose of the bullet to a larger size, possibly affecting combustion, excessive pressure from bullet being set back in case while in magazine by recoil of previous shots.  The list of possibilities is very long and some of them can ruin your day. More than half of the posts above are in answer to this question whether it was asked or not.

Question 2. Will the shot to shot variation in neck tension affect accuracy or muzzle velocity? This was the question I thought this thread was about because of the first two posts. This question has been answered and the answer is no, it doesn’t affect accuracy or muzzle velocity.  it is only worth discussing because a lot of shooters still believe it is important, write that it is important, tell new shooters it is important, and spread information that has been disproven, thus almost certainly untrue because there are no known studies showing it might be true.

Aside from Bottiger's excellent work which should have been enough to kill this particular Zombie you can easily reach the same conclusion by thinking about the relative magnitudes of the forces involved.

The forces required to seat a cast bullet without damage are in the range of near zero to maybe 50 to 70 pounds. The force needed to push it back out are almost certainly less -- maybe even zero as pointed out by Ken and others repeatedly. At any rate pretty small and totally insignificant compared to force of the expanding gas which for a 30 caliber bullet will be in the range of 1,500 pounds to 4,500 pounds depending on the load.

Any shot to shot variation in the tiny force that neck tension could possibly provide will be overwhelmed by the much much larger variation in the force doing the pushing. As a math major might say "it is in the round off error and insignificant. 

John

 

Attached Files

OU812 posted this 21 August 2018

I can see why neck tension would not matter when shooting cast bullets because the bullet should always be chambered to stop against the throat. This resistance makes neck tension null. 

Attached Files

  • Liked by
  • RicinYakima
Shopdog posted this 21 August 2018

OK Paul,I will take a stab at,"which matter and which don't".

First off,ain't much gonna matter if the bullet is undersized or,in anyway "under" developed. This is why bullet fit rises to the top so often in these examinations. It can be looked at as a hierarchy of sorts..... starting with the fit and then diminishing returns as we go down the list.

On a positive side note however,doing certain case prep chores are eliminating that particular potential from effecting other,potentially offending ops. An example;gonna be pretty hard to double charge if you're weighing each. So while it may seem to be a waste of time.... it depends on the specifics or ops "downstream".

Attached Files

joeb33050 posted this 21 August 2018

8-21-18.

This morning while sizing cases, I took some more notes. Neck thickness is .009.

 With .261 bushing: Fired case neck measured .2634; sized, it measured .2612. With .245 diameter bullet seated, .2634.

With .259 Nitride bushing: Fired case neck measured .2632; sized, it measured .2585. With .245 diameter bullet seated, .2632.

Unsized case at .2634 neck diameter with bullet seated measured .2635. On this case, the bullet pushed back to 2.198 when chambered. The sized cases held at 2.210.

Here's something odd. I have been playing with the Dave Lee method of friction fit on the neck when chambering. Fireform, turn the neck a little oversize, then seat a bullet to check if it chambers. Sand with 600 grit paper until it fits. Shoot and do not size, punch out primer, reprime, recharge, seat bullet. The case and bullet will chamber snugly.

This morning, I figured it would be a great idea to size the case in the .259 bushing and seat a bullet. It didn't chamber. I did this 3 times with the same result. I selected another case and seated a bullet without sizing; it chambered. The unsized cases with bullet measured right at .2650 and chambered. The sized cases with bullet measured .2655 and would not chamber.

Any ideas why sizing the case would not let it chamber? It seems spring back may be at work.

 Only an idea. I can neck size or seat bullets so that the body/shoulder junction is enlarged and the case won't chamber/easily. It took me a while to figure out. Will the case that won't chamber, chamber with the bullet out?

Attached Files

Paul Pollard posted this 21 August 2018

In the articles in The Fouling Shot, which I re-read, the following things were done to improve accuracy. 

Cases were sorted by weight, neck thickness measured, cases were INDEXED in the chamber, bullets were inspected and weight sorted, sized and INDEXED, powder charges were weighed.

Which matter and which don't? Is this Better Shooting or BS?

Attached Files

Paul Pollard posted this 21 August 2018

8-21-18.

This morning while sizing cases, I took some more notes. Neck thickness is .009.

 With .261 bushing: Fired case neck measured .2634; sized, it measured .2612. With .245 diameter bullet seated, .2634.

With .259 Nitride bushing: Fired case neck measured .2632; sized, it measured .2585. With .245 diameter bullet seated, .2632.

Unsized case at .2634 neck diameter with bullet seated measured .2635. On this case, the bullet pushed back to 2.198 when chambered. The sized cases held at 2.210.

Here's something odd. I have been playing with the Dave Lee method of friction fit on the neck when chambering. Fireform, turn the neck a little oversize, then seat a bullet to check if it chambers. Sand with 600 grit paper until it fits. Shoot and do not size, punch out primer, reprime, recharge, seat bullet. The case and bullet will chamber snugly.

This morning, I figured it would be a great idea to size the case in the .259 bushing and seat a bullet. It didn't chamber. I did this 3 times with the same result. I selected another case and seated a bullet without sizing; it chambered. The unsized cases with bullet measured right at .2650 and chambered. The sized cases with bullet measured .2655 and would not chamber.

Any ideas why sizing the case would not let it chamber? It seems spring back may be at work.

 

Attached Files

Shopdog posted this 21 August 2018

Probably shouldn't respond,oh well....

Don't confuse,... tension.... friction(seating).... hold.

K&M,21st century and some other co( CRS) has been making bullet seating force gauge equipment for a loooong time. It's been pretty well documented in long range JB shooting that batching rounds with very low ES on these gauges shows up on paper.

Just an observation, what gets this discussion derailed is..... does a bullet move forward at the moment of ignition.... OR ..... case neck expands cutting all bullet to case "ties" free. Solve this,and it may help show what once held dear,may not represent the full spectrum of engineering available at any one point.

Attached Files

  • Liked by
  • RicinYakima
shootcast posted this 21 August 2018

I don’t shoot as well but have experimented with neck tension. Jerry’s artical took a great deal of tIme experimenting. One thing I would add I have read in reloading manuals. Since neck tension can be from a slip fit to a rather tight force the powder used can have a effect. Jerry test was with one powder and one bulletin and one firearm. My test showed loose necks and fast powders are better than loose necks and slow powders. To each there own but after lots of trial and error I believe you need enough to hold the bullet firmly but not excessively.

 

Attached Files

  • Liked by
  • RicinYakima
John Alexander posted this 20 August 2018

No, John, the reason why you haven't progressed in this century is because of myopia, group think, and lack of curiosity.

Geargnasher,

That is a pretty ugly list character traits to lay on CBA shooters by a non-member who as far as I know has never had his shooting results printed in CBA match reports.  The CBA shooters I know are a pretty respectable bunch who share their knowledge freely both in TFS and on this forum. They also have the courage to show up at matches where their groups are measured by others and if their groups don’t match the results they have claimed on the internet that’s just the way it is.

Group think?? Virtually all my TFS articles are challenging the conventional wisdom about cast bullets. Please look up the meaning of "group think". 

As far as “lack of curiosity” I have offered to send you an article that that would show any open-minded person that your belief in the importance of variation in neck tension to accuracy is wrong and explain why -- all at no cost.  So far you apparently haven’t been curious enough to send your address.

==================

You and others have gone far out of your way to prove my statement "wrong".

==

That’s because it was wrong.  Having misleading claims on the forum without a rebuttal is not helpful if we are going to learn anything. If you didn’t agree, an intelligent response would have been to submit evidence that you were right, not attack the character of those who disagree with you.

Learning is the major reason the CBA offers this forum.  If enough open-minded shooters participate we will all learn things we didn’t know. It is not a place for grand claims that aren’t verified and can’t be questioned.  If you don’t like others disagreeing with you and citing evidence you are wrong, you are in the wrong place.

I'm tired of your resistance to learning, so have fun doing it the same old way and I'll get back to more productive endeavors.

While you are looking up group-think you may want to check out “irony” as well.

John

 

 

Attached Files

  • Liked by
  • dbarron
pat i. posted this 20 August 2018

Anyway....Paul I expect the bullet to seat deeper into the rifling when using a tighter button but wonder if once the bullet was seated and the case expanded if it would take any more force to get it moving no matter what size button you used. My gut tells me it wouldn't. Could be wrong though.

Attached Files

Show More Posts
Categories
Search
Popular Tags
This Weeks High Earners
Hot Topics
Close