The Lee Collet Sizer is dead consistent
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Velocity Effect of Bullet Tension
- Thread starter Tiny Tim
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What part are you disagreeing with?
Bobcape
Well-Known Member
This is a good short video on neck tension as it applies to ES by Shawn Carlock.
He's shooting Hammers, anything less than .003 is iffy and the powder charge takes care of neck tension???? I'm not following you there
its all about consistency from load to load, case to case, explosion to explosion and. Shot to shot. If any action in the process is sketchy, so goes the shot. However if every action is perfectly repeated from the last, we just adjust our crosshairs to the center and print tiny little groups.
The carbon deposited in the finest film in the neck is a lubricant for the reload. The state of hardness of reformed/ re-fired brass
is not the problem. It is a function of brass life.
be j tension is not equal amongst all loads but if you have a lot of new brass or a lot of fired brass, turned necks or unturned necks, crimped or uncrimped, it matters not. As along as they are consistent. Measuring the seating pressure from otherwise "identical" cases can yield groups of those with variations that might be a ghost in the machine. If they are "identical" they will all be in one hole. just saying
Well we have a lot of certainty showing up in this thread. I have admitted I am not certain of my theorizing about this, but I have some reservations about the certainty being shown above.
First, I would challenge the theory that seating resistance equals neck tension of bullets exiting the case. I listed several possible areas where seating resistance might vary: neck annealing, alignment of the bullet in the die, cleanliness of the neck when seating, chamfering of the neck, etc.
Second thought: if you are measuring the resistance of the bullet being seated, you are not measuring the resistance of the bullet exiting the case. At the very least, the pressure in the case at the moment of ignition will change the neck tension, unless the bullet has completely departed the neck before the case begins to expand -- are we confident we know this?
I do not dispute that consistency is important in reloading, especially for long range shooting (F-class and other LR shooting). We all strive for consistency to varying degrees: same brass weight, same diameter flash holes, same powder charge, same primer seated in the same way, and consistent bullet weight and runout, same case neck thickness, etc.
But is consistency in bullet seating does not automatically equate to consistency in neck tension when the bullet starts moving. Or does it?
First, I would challenge the theory that seating resistance equals neck tension of bullets exiting the case. I listed several possible areas where seating resistance might vary: neck annealing, alignment of the bullet in the die, cleanliness of the neck when seating, chamfering of the neck, etc.
Second thought: if you are measuring the resistance of the bullet being seated, you are not measuring the resistance of the bullet exiting the case. At the very least, the pressure in the case at the moment of ignition will change the neck tension, unless the bullet has completely departed the neck before the case begins to expand -- are we confident we know this?
I do not dispute that consistency is important in reloading, especially for long range shooting (F-class and other LR shooting). We all strive for consistency to varying degrees: same brass weight, same diameter flash holes, same powder charge, same primer seated in the same way, and consistent bullet weight and runout, same case neck thickness, etc.
But is consistency in bullet seating does not automatically equate to consistency in neck tension when the bullet starts moving. Or does it?
muzzletalk
Active Member
I'd echo this. Well said.
Muzzlletalk: And how certain are you that the only variable that was different was the next tension? Not challenging you -- just trying to get a handle on this.
david g ranes
Well-Known Member
You serving breakfast if I'm your guest I like pancakes I'm just stating what he said I don't agree that 10 thou will stick a bullet he wasn't just talking about just match shooting he was talking in general get him to be your guest maybe he will explain it to you so we will both know what I was sayin was more of a question than a statement the only bullet I ever stuck was one that you could seat the bullet by hand and it was bench rest. David
IHFarmer07
Well-Known Member
Do you have donuts forming inside the case at the shoulder/neck junction? This WILL make a huge difference. All of the rifles I use for precision and long range has a several step case prep with neck turning every time to get rid of the donuts and I have played with neck tension myself, it can be a hair pulling, $$$$ rabbit hole to go down. I've bought a k & m arbor press with a gauge pack to measure tension and with that I even polished the necks of 5pcs of brass to a shine! I could not get them to seat without maxing the force pack out on the k & m so I used my co-ax, with that, I had very good everything, es/sd and I think the group was awesome too but there is NO way I'm doing that to every piece of brass I reload!!
In my findings on the rifles I've played with, high neck tension ends up with higher velocity most times with either an accuracy and es/sd loss or gain, low tension usually drops the velocity with either an accuracy and es/sd loss or gain. YOU have to figure out what your gun/reloaded ammo combo likes. Trigger time never hurt nobody. In my playing with neck tension on the liter side it's has been more accurate at times, but it seems to me that the liter the neck tension the harder it is to have all brass consistent with that tension.
I just got done messing with my 6.5prc with Badlands Bulldozers and Gunwerks brass using less and more neck tension, I thought it helped but later in my testing my thoughts on it helping seemed to fall apart. I use a special die made by Kenny Porter, his let's you use gage pins which is tool steel and is very very accurate on sizes. You can find the gage pins on Amazon. In my chase for better es and sd numbers the MAIN thing I found that dropped those numbers was donuts, you get rid of those and you can easily can get high es/sd's way down!
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muzzletalk
Active Member
I'm generally one to read vs. post but this post caught my eye. I think "neck tension" is overlooked. I'll be the first to admit, I'm an expert in absolutely nothing. But I can tell you what I have found in all my testing. So take this as just one mans view on the subject.
It is impossible to be certain of all other variables. If you change one thing, you've changed everything. I've spent a considerable amount of time, effort, and money trying to reduce or remove the variables that I can control. When I'm testing theory, problem, or function all prep is completed without deviation. Primer pocket depths are checked, primer seat depths are checked, brass sorted, bullets sorted, etc.. the list goes on. Primers are seated with Primal Rights CPS, Auto Trickler for powder, and more to the point of this discussion, a hydro bullet seat press to validate seat pressure. The hydro bullet seat press was my biggest asset when I tested "neck tension". It is about as close as I can get to measure the tension placed on a bullet when seated since we can't directly measure tension.
I have found more variance in accuracy and little in precision based on "neck tension". Meaning my point of impact may change, however, how close each shot was to one another wasn't profound. Of course, you will most likely see some variance but I believe that is dependent on other factors like tolerances in manufacturing the bullet, etc...
when I load for competition or hunting, I prep with an expansion mandrel. a hydro seating press takes way to much time. I use an expansion mandrel that is the same size as the bullet for my bolt guns with minimal recoil. For my 6mm rifles, I use a .243 mandrel, 6.5 Creed I use a .264. You can certainly feel the pressure variations in seating bullets when you use a mandrel that's the same caliber as the bullet. You'll also be surprised just how much tension spring back applies to a seated bullet.
Just to note, I'll use more neck tension when I shoot the 300 PRC or larger magnum calibers for obvious reasons.
Hope this helps.
Marine sniper
Well-Known Member
Talking about neck tension in inches is very difficult to quantify; if you really want to get serious about monitoring neck tension get one of these with a force pack.
This press measures the actual pounds of force it takes to seat a bullet, I use one- trust me it will open your eyes to many things.
Comparing neck tension in inches does not give a full picture.
kmshooting.com
This press measures the actual pounds of force it takes to seat a bullet, I use one- trust me it will open your eyes to many things.
Comparing neck tension in inches does not give a full picture.
Arbor Press | K+M's Precision Reloading Best Arbor Press
Arbor Press | K+M's Precision Reloading Best Arbor Press used w/ inline bullet seating and neck sizing dies for a home loading bench or out at the range.
kmshooting.com
IHFarmer07
Well-Known Member
I think, IIRC, .001" of neck tension took anywhere from 25-40#'s dry and using say the imperial dry lube or die wax on the bullet it could've been easily 20-25# IIRC using the mandrel to final ID neck size for a .224cal. Annealing every time will help a lot and also neck tension has to do with how "deep" you seat the bullet as well. Some guys go for stopping the bearing surface of the bullet at the shoulder neck junction and some go for the depth depends on the size of bullet, so, if you have a .284, .264 ect they seat that far into the neck.Talking about neck tension in inches is very difficult to quantify; if you really want to get serious about monitoring neck tension get one of these with a force pack.
This press measures the actual pounds of force it takes to seat a bullet, I use one- trust me it will open your eyes to many things.
Comparing neck tension in inches does not give a full picture.
Arbor Press | K+M's Precision Reloading Best Arbor Press
Arbor Press | K+M's Precision Reloading Best Arbor Press used w/ inline bullet seating and neck sizing dies for a home loading bench or out at the range.
I will admit I'm not familiar with Hammer bullets and the amount of neck tension required. Thank you for pointing that out!
The correct powder charge (and seating depth) cures a lot of problems....In my experiences less neck tension required more powder to achieve consistent results and vice versus. I have never personally found the need or any added benefit to adjust neck tension on a FINISHED load. That said if your are struggling to get a good consistent shooting load...changing to more or less neck tension could certainly alter the course of initial load development.
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The problem with seating force gauges like the K&M and 21St Century are those numbers can be easily manipulated with the amount of speed with which you seat the bullets and the amount and type of lube used.
With consistent reloading practices the variance in seating force probably doesn't vary more than 10-15psi and that is being generous. I doubt many if any could/can shoot the difference unless the numbers were on the opposite ends of the spectrums.
