Neck Tension questions

[fastarget]

Curious,

How much can neck tension affect pressure/velocity in a cartridge? is there a percentage in velocity change?

The universal tension per say seems .002, why?

What bushing do you choose if your brass is measuring in between sizes? ex loaded round is .3155, do you choose a .313 if you want .002 tension or .314? or does it really matter?

 

[savagedasher]

It' depends on how you are loading jumped or jamming .Larry

 

[fastarget]

In the 284 jumped, in the daughter's Dasher jammed. On a learning quest .

 

[savagedasher]

In the 284 jumped, in the daughter's Dasher jammed. On a learning quest .

I can't help I shoot a dasher jumped. Larry

 

[lawrence97]

.002 tension is that magical number most preach about. I used to run anywhere from .001-.0025. Now I let the rifle and target decide what is best. My initial testing is done with .002 and once my powder/seating depth is sorted out I will test neck tension at the distance I will be shooting at.

 

[fastarget]

Very good, why .002 do you think?

By the Way, The questions are in General, apply to reloading all calibers.........

 

[Scott Harris]

Carl, much over .002 and the bullet becomes an expander mandrel...getting scratched and damaged while performing such duties. "Too much" neck tension can be identified when you pull a bullet from a loaded cartridge and notice it is all scratched up. From a practical standpoint, .003 is about the most tension you can have before damaging the bullet becomes a concern.

At the other end, there are lots of preferences. Some folks prefer to "soft-seat" the bullet which means they have .001-.000 tension and seat the bullet long, letting the chamber do the final seating. Personally, I prefer .002 -.003 tension with the sizing die and then run a mandrel that is .002 under through the neck. I don't really play with neck tension or seating depth for that matter.....ima heathen.

A lot of things impact neck tension: neck thickness, annealing, cleaning, bullet coatings, etc. Regardless, I like to see that the bullet is un-scratched when/if I pull it from a loaded cartridge. If it is scratched up, that's a problem in my book. You will have to figure things out for yourself, but I think most folks are running .002 as you said.

 

[chkunz]

Carl, much over .002 and the bullet becomes an expander mandrel...getting scratched and damaged while performing such duties. "Too much" neck tension can be identified when you pull a bullet from a loaded cartridge and notice it is all scratched up. From a practical standpoint, .003 is about the most tension you can have before damaging the bullet becomes a concern.

At the other end, there are lots of preferences. Some folks prefer to "soft-seat" the bullet which means they have .001-.000 tension and seat the bullet long, letting the chamber do the final seating. Personally, I prefer .002 -.003 tension with the sizing die and then run a mandrel that is .002 under through the neck. I don't really play with neck tension or seating depth for that matter.....ima heathen.

A lot of things impact neck tension: neck thickness, annealing, cleaning, bullet coatings, etc. Regardless, I like to see that the bullet is un-scratched when/if I pull it from a loaded cartridge. If it is scratched up, that's a problem in my book. You will have to figure things out for yourself, but I think most folks are running .002 as you said.

Excellent response !

 

[dmoran]

Myself, if I want the best accuracy out of my load, I have to test neck tension to see what amount produces the best accuracy. And at times revisit tension as the brass is cycled.
Donovan

 

[Alex Wheeler]

Carl, much over .002 and the bullet becomes an expander mandrel...getting scratched and damaged while performing such duties. "Too much" neck tension can be identified when you pull a bullet from a loaded cartridge and notice it is all scratched up. From a practical standpoint, .003 is about the most tension you can have before damaging the bullet becomes a concern.

At the other end, there are lots of preferences. Some folks prefer to "soft-seat" the bullet which means they have .001-.000 tension and seat the bullet long, letting the chamber do the final seating. Personally, I prefer .002 -.003 tension with the sizing die and then run a mandrel that is .002 under through the neck. I don't really play with neck tension or seating depth for that matter.....ima heathen.

A lot of things impact neck tension: neck thickness, annealing, cleaning, bullet coatings, etc. Regardless, I like to see that the bullet is un-scratched when/if I pull it from a loaded cartridge. If it is scratched up, that's a problem in my book. You will have to figure things out for yourself, but I think most folks are running .002 as you said.

Have to disagree. From multiple tests at 1k yards, have seem up to .006" neck tension shoot best. I personally find everything I test prefers at least .003" tension. Bottom line, dont take our advise, test it in your combo. That goes for all load questions, IMO.

 

[dkhunt14]

Have to disagree. From multiple tests at 1k yards, have seem up to .006" neck tension shoot best. I personally find everything I test prefers at least .003" tension. Bottom line, dont take our advise, test it in my combo. That goes for all load questions, IMO.

+1

 

[Scott Harris]

Have to disagree. From multiple tests at 1k yards, have seem up to .006" neck tension shoot best. I personally find everything I test prefers at least .003" tension. Bottom line, dont take our advise, test it in your combo. That goes for all load questions, IMO.

Alex, I do completely agree with testing all ideas rather than taking things as gospel. "neck tension" is a very fuzzy idea. My brass is .013 - .014 thick and I"m guessing many of you turn your necks thinner than that. Therefore, our neck tension may end up being closer than it first appears. But, I do believe you should check the bullet condition and prevent damage. Have seen some great competitors that use next to nothing for neck tension and soft seat and others use lots of neck tension. Like many things with reloading, I simply aim for 100% consistency from cartridge to cartridge.

 

[Joe Salt]

I agree with Alex and Matt just like with seating depth, if you start into the lands and work your way out. You should do the same with neck tension, start at .002 and increase .001 at a time. I know what everyone's going to say! But my barrel will be worn out before I find the spot. Well if that's the case maybe you need a new barrel.

Joe Salt

 

[fastarget]

Alex, I do completely agree with testing all ideas rather than taking things as gospel. "neck tension" is a very fuzzy idea. My brass is .013 - .014 thick and I"m guessing many of you turn your necks thinner than that. Therefore, our neck tension may end up being closer than it first appears. But, I do believe you should check the bullet condition and prevent damage. Have seen some great competitors that use next to nothing for neck tension and soft seat and others use lots of neck tension. Like many things with reloading, I simply aim for 100% consistency from cartridge to cartridge.

Scott,
Thank you for the reply, and your generous help from the very beginning. Consistency is key I am learning, now trying to get an understanding of some of the factors in reloading to make it repeatable. I have had some excellent groups with .001-.003....

Is it normal to get the brass/silk threads when you use a bushing die on your brass. Seems to only happen on brass that has had necks turned, never occurred on 6.5-284 no turn necks.

I will continue to try out different tensions for my brass is like Scott's .0135-.0140 + or _ .0002, so tension may be varying by .005.

 

[Mozella]

I would agree that consistency is probably more important than the absolute value. You certainly want enough tension to hold the bullet and that will be higher if you feed from a magazine and could be much lower if you handle your ammo carefully and load one at a time using a "soft seat" technique.

Some people who jam bullets might elect to use increased tension because if you must clear your chamber with a round in place, you don't want to pull the bullet and dump powder all over the place, especially in the middle of a timed competition. That consideration might apply to a hunter as well.

 

[tenring]

What are brass/silk threads? Like so many things in this game, .002 neck tension sometimes works, other times not. You need to try various bushings and test each change at the range, just as you would with bullets, powders and primer. There is no "one size fits all".

 

[fastarget]

What are brass/silk threads? Like so many things in this game, .002 neck tension sometimes works, other times not. You need to try various bushings and test each change at the range, just as you would with bullets, powders and primer. There is no "one size fits all".

After sizing with a bushing die on necks that have been turned, I find fine threads of brass, pushed around the shoulder or filling up the die above the bushing.

 

[dmoran]

After sizing with a bushing die on necks that have been turned, I find fine threads of brass, pushed around the shoulder or filling up the die above the bushing.

After you turn the necks polish the necks with fine steel-wool, is my advise.
Donovan

 

[Alex Wheeler]

I would agree that consistency is probably more important than the absolute value. You certainly want enough tension to hold the bullet and that will be higher if you feed from a magazine and could be much lower if you handle your ammo carefully and load one at a time using a "soft seat" technique.

Some people who jam bullets might elect to use increased tension because if you must clear your chamber with a round in place, you don't want to pull the bullet and dump powder all over the place, especially in the middle of a timed competition. That consideration might apply to a hunter as well.

Absolutely not, look at Toms ladder test he posted. Thats shot a 1000 yards. The obvious winner is .0047" neck tension (263 bushing). Tom and these guys are giving away GOLD.

 

[fastarget]

After you turn the necks polish the necks with fine steel-wool, is my advise.
Donovan

Can and will do , thanks. Yes lots of good info here, really helpful.

Any problems if I had gotten a bunch of brass neck sized, decide I want to use tighter tension then run the brass through a tighter bushing?