Neck tension - looking at it the wrong way?

[ebb]

If bullet neck opening before bullet moves is desirable then seating into the lands is a sure way to accomplish that.

 

[mikecr]

I'm sure you can still add/subtract starting pressure, while into the lands, with tension.
But normal tension variances probably matter less.

 

[BoydAllen]

Test and believe your targets. I have done that and in my test changing the bushing made a definite difference on the target, it was clear. All of these theoretical arguments are fine, but they are usually full of assumptions about things that have not been observed directly, and at that point they become my visualization vs. yours.

Some of you may know that I have made a hobby of helping those that want it, to improve their shooting results. It is something that I have enjoyed, and it has taught me a lot about human nature, mine and theirs.

One thing that I have learned is that people are absolutely tenacious about holding on to their assumptions, and even when presented with on the target proof of their errors, will launch off into the land of "you would think".

I have had the privilege of meeting many excellent shooters, and the one thing that sets them apart is that they do their own testing of just about every variable that you can think of, and some that, until they mentioned them, I had not.

 

[rwj]

I agree that the neck expands first. If the bullet slipped out the gas pressure would equalize on the outside of the neck and the neck would not expand. Plus I have seen when with overly long freebores and bullets barely in the neck, this exact thing happened. The bullet slid out of the neck and no expansion occurred.

This a leading cause of soot on the case shoulder/body?

 

[AlNyhus]

Good question. I was in a conversation about this and a national champion BR shooter that had a reputation as knowing his stuff, said that all neck tension issues were mute when the bullet was loaded to touch the rifling as it was chambered. I have always been curious if this was the fact.

While that can be true in certain situations, that's not an absolute for every chambering/bore size/bullet/powder/throat geometry, etc. situation.

One size doesn't fit all. Which is why this stuff gets tested on an individual basis.

Good discussion! -Al

 

[dusterdave173]

To me new brass is sketchy--twice fired and neck issues go away or at least diminish--no matter what method I use I can't shoot the difference of the things in this topic--I started out with 223 plain old Redding FL set with button. Spent on neck dies and 21st century mandrels etc--Have decided that brass brand, seating depth and as much care as I can muster in the process works better than all of the "tricks" for me. Some bullets are easy as pie--I have said before if a 53 Vmax with N133 is in front of the bolt head and behind the barrel crown it will shoot -- some projectiles are like that -others not so much. Finding a solid combo of all the ingredients--that play well together in my rifle seems to get me to acceptable results. I find myself back to the basics time after time to get Repeatable results.
I LOVE reading these threads and learning--
My poor old eyes and body decline--as my knowledge and experience increase--I got into this Way too late
Good thread--good gang here on this site
Thanks

 

[VA_XTC_Shooter]

Test and believe your targets. I have done that and in my test changing the bushing made a definite difference on the target, it was clear. All of these theoretical arguments are fine, but they are usually full of assumptions about things that have not been observed directly, and at that point they become my visualization vs. yours.

Some of you may know that I have made a hobby of helping those that want it, to improve their shooting results. It is something that I have enjoyed, and it has taught me a lot about human nature, mine and theirs.

One thing that I have learned is that people are absolutely tenacious about holding on to their assumptions, and even when presented with on the target proof of their errors, will launch off into the land of "you would think".

I have had the privilege of meeting many excellent shooters, and the one thing that sets them apart is that they do their own testing of just about every variable that you can think of, and some that, until they mentioned them, I had not.

This is exactly why I am on this forum asking questions, to learn, improve my shooting.

The gun industry is full of all kinds of dogmatic ideas and assumptions. I don't expect, in this case regarding neck tension, to see a one size fits all. I am hoping to get a better understanding so I know what to test and look at.

For example, I see the logic in the idea that if the bullet is jammed, neck tension doesn't matter as much. But sounds like others have tested that and seen a difference. Of course, you always have to ask, how was it tested. Were these 3 shot comparisons or was it a thorough, repeated results, test? If only we all had plenty of time and money.

 

[BoydAllen]

This is exactly why I am on this forum asking questions, to learn, improve my shooting.

The gun industry is full of all kinds of dogmatic ideas and assumptions. I don't expect, in this case regarding neck tension, to see a one size fits all. I am hoping to get a better understanding so I know what to test and look at.

For example, I see the logic in the idea that if the bullet is jammed, neck tension doesn't matter as much. But sounds like others have tested that and seen a difference. Of course, you always have to ask, how was it tested. Were these 3 shot comparisons or was it a thorough, repeated results, test? If only we all had plenty of time and money.

Testing does not require a lot of money. The fastest way to do it is to move your reloading to the range, which is a lot easier than is sounds. As far as the number of shots it takes to produce reliable data goes, that depends on your setup. The more variables that you can control the fewer shots it takes it learn something for sure. A good example of this is wind flags. When you go to the range do you see many, or anyone using some kind of indicator to see what the wind is doing between their bench and the target? Probably not. IMO that is probably because of a couple of things. They do not realize how much effect shot to shot variations have on their results, and they think that the wind that they feel at the bench is uniform going down range. If you do not do your own testing, in many cases you will not be able to reliably distinguish good advice from bad. Believe me, counting forums and YouTube, there is a lot of bad advice out there, given by people who can be quite convincing, unless you have done what they are talking about. Finally, some advice on how to get the most from a forum like this, ask specific questions, and do your best to determine the order of importance of things. For instance, it is stupid to worry about hundredths of a grain of powder if you are shooting a factory rifle that has not had its action bedded. While that is an extreme example, I see things similar to it all the time, only to a lesser degree. Take care of the big stuff, before worrying about the little stuff. A good start would be to describe the equipment you are working with, and the results you are getting, not the wallet group, but your typical result. Getting back to the number of shots it take to have reliable results, for my best rifle, shot off of a concrete bench, on a day when the wind is light and predictable, with wind flags between me and the target, at 100 yards, if there is paper between the first two bullet holes, I do not need to fire a third round. I should mention that my best rifle is a custom built 6PPC with a 2 oz. trigger, and a proven high magnification scope. On the other hand, I started out shooting an unmodified 788 Remington, and when I started reloading for it, it was with a Lee loader, and a plastic mallet. With that, it took a few more shots to see differences, but not many.

 

[AlNyhus]

This is exactly why I am on this forum asking questions, to learn, improve my shooting.

The gun industry is full of all kinds of dogmatic ideas and assumptions. I don't expect, in this case regarding neck tension, to see a one size fits all. I am hoping to get a better understanding so I know what to test and look at.

For example, I see the logic in the idea that if the bullet is jammed, neck tension doesn't matter as much. But sounds like others have tested that and seen a difference. Of course, you always have to ask, how was it tested. Were these 3 shot comparisons or was it a thorough, repeated results, test? If only we all had plenty of time and money.

It's not as complicated to test this stuff as it would seem. Or how people make it. The first rule is to use wind flags. If that's not in place, any 'results' aren't valid. A lot of what gets regurgitated on forums and the InterWeb are 'facts' based on people not using flags. A simple analogy is the GIGO term used when inputting data into a computer: Garbage In Garbage Out.

Good shootin' -Al

 

[gunsandgunsmithing]

It's not as complicated to test this stuff as it would seem. Or how people make it. The first rule is to use wind flags. If that's not in place, any 'results' aren't valid. A lot of what gets regurgitated on forums and the InterWeb are 'facts' based on people not using flags. A simple analogy is the GIGO term used when inputting data into a computer: Garbage In Garbage Out.

Good shootin' -Al

Oh, but I'm shooting the 230gr Ballistic Magic bullets. The wind doesn't affect them at only 100 yards, so I do all my testing at 300.
Flags look silly and are too much trouble. Oh, I know the short range guys need them with those short, light flat base bullets though.

Yes, sarcasm intended. Lol!

 

[dryhumor]

Neck prep. Turn or don’t turn. I can see the thickness variance or non concentricity being pushed to the inside whether a bushing or FL die. I can see that that would increase or decrease neck tension.

A mandrel’d neck providing a consistent inside gives me the ability to measure the outside. If I don’t turn, the only means I have to get neck tension close is to measure and batch. I do see a positive in that, particularly after the first firing and resizing. I can feel it as I seat bullets on once fired cases.

I should probably just turn necks and be done with…..

 

[BoydAllen]

Neck prep. Turn or don’t turn. I can see the thickness variance or non concentricity being pushed to the inside whether a bushing or FL die. I can see that that would increase or decrease neck tension.

A mandrel’d neck providing a consistent inside gives me the ability to measure the outside. If I don’t turn, the only means I have to get neck tension close is to measure and batch. I do see a positive in that, particularly after the first firing and resizing. I can feel it as I seat bullets on once fired cases.

I should probably just turn necks and be done with…..

It depends on your total setup and what you are using the rifle for. I would never bother with turning necks for a field rifle. This gets back to the question of your total setup. Do you have all of the big stuff taken care of? Back in the day, for varmint calibers like my .222 and .223, after bedding and floating, and some trigger adjustment, loading with typical one piece dies, I reliably got under half MOA accuracy, well under. The question as to whether to turn depends on a lot of things, and if you do not given details about your total setup, it is impossible to give good advice.

 

[dryhumor]

It depends on your total setup and what you are using the rifle for. I would never bother with turning necks for a field rifle. This gets back to the question of your total setup. Do you have all of the big stuff taken care of? Back in the day, for varmint calibers like my .222 and .223, after bedding and floating, and some trigger adjustment, loading with typical one piece dies, I reliably got under half MOA accuracy, well under. The question as to whether to turn depends on a lot of things, and if you do not given details about your total setup, it is impossible to give good advice.

Some are bedded, some are in HS or BC stocks. Primarily hunting, with the range common of 2-300 yards. Crop fields 4-600 yards. Retired now, so I actually have time to fully engage instead of catch as catch can when time permitted.

 

[BoydAllen]

Some are bedded, some are in HS or BC stocks. Primarily hunting, with the range common of 2-300 yards. Crop fields 4-600 yards. Retired now, so I actually have time to fully engage instead of catch as catch can when time permitted.

OK, now we have some information. First tip, go to erniethegunsmith.com and read up on bedding stocks with bedding blocks. A friend, who is a smith has tried that method and it worked very well. My friend builds top level benchrest rifles. This was for a fun gun to shoot plates with, with his buddies.

 

[K22]

My simplistic approach to neck tension is that consistency is the most important aspect for me. Thus, my loads / rifles are tuned to that consistency. Also, it is critical that I have sufficient tension to prevent bullet movement of cartridges in the magazine.

Also, I do not use any elaborate reloading methods relative to neck tension other than having a range of expander buttons for my standard full-sizing dies so I can easily vary the neck tension depending on a lot of cases and specific rifle married to those cases.

I am not saying that the elaborate process / methods are not necessary for benchrest or F class long range competitors, maybe they are but as "The Rifleman" once said when asked "how good are you", he replied, "I am good enough."

PS: I often wonder about this neck tension issue when I see sub 1 moa groups routinely shot at the range with Savage 6.5 Creedmoor rifles and premium factory ammo which are crimped and have remained seated for indefinite periods of time (neck weld) since being manufactured.

 

[jelenko]

pressure, expands neck to chamber walls, then bullet moves. Some gases move around bullet between case neck forward until bullet moves forward and seals against the forcing cone.

But, how is the neck expanded if there's no gas between the bullet and the brass to push on the brass?

It would seem to me that the gas pressure expands the neck behind the bullet as the bullet moves forward. The neck would be fully expanded just as the bullet leaves the neck.

 

[CharlieNC]

The mechanism by which factors at the neck (seat depth, annealing, sizing, etc) has been elusive to me. Interestingly the RSI Pressure Trace web site gives an example demonstrating seating depth has a significant effect on chamber pressure. It's rare to see individuals report using this tool for testing and understanding, but of course the target rules.

 

[VA_XTC_Shooter]

But, how is the neck expanded if there's no gas between the bullet and the brass to push on the brass?

It would seem to me that the gas pressure expands the neck behind the bullet as the bullet moves forward. The neck would be fully expanded just as the bullet leaves the neck.

I think you are looking at it like a corked champagne bottle. Unlike the glass and champagne, the brass expands with pressure and in the brass, the first area of the case to expand is the thinnest neck/shoulder area. You don't have to have space to push outward, the gas is pushing at the vertex of the bullet and case and pushing the case outward toward chamber wall.

This is at least how it works in my mind. I don't have video footage, lol.

 

[BoydAllen]

I'm sure you can still add/subtract starting pressure, while into the lands, with tension.
But normal tension variances probably matter less.

Years ago, I tested this starting with a well tuned load for my 6PPC. The load was shooting really well in a .262 chamber. Since I had the bushings with me, I backed up to .001 neck tension, and the group went to hell. Next I tried .002 and it got better, but was still not as good as it had been at .003. This sort of thing is so easy to test that it makes me wonder about all those who seem to prefer conjecture to what is such an easy test. I should add that 133 likes neck tension. These days I might be using .004. Other powders do not share this characteristic. In a PPC, LT32 seems to like less. .0015 to .002 would be fine.

 

[mikecr]

The moment necks expand at all free of bullet bearing, gas goes around the bullet. If you have a lot of chamber end clearance, some of the gas scoots around the outside of the neck, and with a lot of neck clearance the soot can reach all the way to shoulders before neck sealing occurs.
There is nothing 'good' about that.

With tight chamber end and neck clearances, necks snap to seal with little to no sooting.
This doesn't hurt a thing.