.002 neck tension....

Tod osier

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if the neck inside is sized to .002 below bullet diameter, how much grab is there? In other words, how much force is needed to move the seated bullet? Can it be pushed into the case with firm pressure? A lot of people are shooting for .002 (or .001), I assume that is a hunting ready "tension": waterproof and damage resistant. I have not read how tight the bullet is after seating.

My neck is measuring out at .002 under after using a lee collet die (using calipers to measure I'm getting consistent measurements). The grab isn't what I would consider great and pushing in on a bullet it slipped deeper. Are my expectations too high for a non-crimped round? Anyone have guidance as far as a way to express how tight the bullet should be? I can't grab it and twist it out, but I can push it in further after seating with good pressure that doesn't destroy the tip.

Ammo is shooting very well, so I'm really happy there.
 

rayporter

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a lot of the tension has to do with how many times the case has been shot. personally i use at least .003 when competing and a little more for hunting ammo. when cases get too work hardened i make new cases.

the .001 and .002 you hear about is generally competition ammo. it used to be the rage to turn brass to a perfect fit in the chamber and soft seat bullets by hand [fingers] there are few shooters doing this now. most of us use at least .002 clearance of the neck in the chamber and .003 tension.

hunting ammo for sure needs enough to insure it wont move. i have carried p dog ammo that was light enough to move on the trip out. and i have also carried p dog ammo that was slightly long and seated the bullet when i was ready to shoot.

but heck if it shoots -shoot it.
 
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Tod osier

Tod osier

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Thanks, I tested a few more and what I have now is for sure less tension than I would want for hunting. I'll shoot these up and get the necks a bit smaller next run.
 

VernAK

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High recoil rifles can pull bullets on rounds in the magazine.....when testing loads, do it with a full magazine and measure that last round for length.

Personally, I like the Lee collet crimping die.
 
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You have to account for the springback as Well. The brass is going to stretch and then spring back a bit.....account for that.
 
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Tod osier

Tod osier

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Thanks guys, I think I can put more compression on the neck with the die and I have the undersized mandrel for the die if I can't get satisfaction with the standard. I have some rounds to burn through first.

T
 

rayporter

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if you are using a die with an expander you may with to change to a bushing die to be able to adjust your tension. it is also thought that the expander is not good for making straight ammo.

the spring back changes with each firing. minuscule, yes, but it builds up.

the only cartridge i have tried to crimp is a 45-70. and it did not need it-[single shot]. i dont think neck tension is well understood. it is hard to study because seating pressure is not the same as the pressure needed to move a bullet forward.

with some tension most -heck, all- ammo will get very tight after a week or so setting around. sometimes this is called a cold weld, where the bullet sticks in the neck. if you have some old ammo laying around reseat a couple bullets and you will understand the concept. you will have to use a lot more pressure to reseat a bullet than when you seated it originally. there will be a distinct pop as the bullet is seated.

you would expect this to have a detrimental effect on accuracy but many of us benchrest shooters dont see it affecting the ammo. and obviously hunting rifles are not affected.

i have had left over ammo from a match that set for a week or more and shot it many times with outstanding results.

just last month i dug out a rifle and found some bullets left over from last year. it had been shooting in the .3 to .5 at 200yd back then.

i put the seven shots left over into a nice big .190 at 100y. i poped one for a fouler and the tension was drastically different than when first seated.

neck tension is not particularly understood.
 

rfurman24

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A lot of variables have an affect on neck tension. We, as reloaders, typically express neck tension as the amount of neck sizing we do. The most common way we do that is to load a road with the brass and bullet we will be shooting and measure its total neck thickness. We then subtract .002(or whatever is desired) from that number and use a bushing of that size if using bushing dies. If using regular dies it is not really adjustable. The amount we size can be adjusted and checked for group impact but I have never felt the need to do so.
 

GKPrice

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A lot of variables have an affect on neck tension. We, as reloaders, typically express neck tension as the amount of neck sizing we do. The most common way we do that is to load a road with the brass and bullet we will be shooting and measure its total neck thickness. We then subtract .002(or whatever is desired) from that number and use a bushing of that size if using bushing dies. If using regular dies it is not really adjustable. The amount we size can be adjusted and checked for group impact but I have never felt the need to do so.

Nor have I ^ ^ ^ ^ ^ ^
 

danmayland

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I have felt the need to make sure my neck tension in my custom 7LRM is consistent. I've noticed with the crappy and only available Hornady brass that the neck tension is largely inconsistent. I have to turn the necks and then resize down .003 to get consistent tension. I fought the accuracy in my gun for over a year before I realized the neck tension was the cause of the majority of my flyers. I think it's worth noting that more neck tension equates to more pressure. I've noticed that at .004 my groups open up quite a bit. I use a bushing size .003 smaller than the diameter of a loaded round because of spring back to achieve .002 tension. It's also worth noting that my loads are pretty hot. It might not be as much of a problem is a more mild load. My .2C


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Tod osier

Tod osier

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With the collet die, I have some control over the neck inside diameter, I'm mainly wondering what .002 (or .001 or .003) feels like. Should .002 have the bullet so tightly grabbed it wouldn't get bumped in (or able to be pushed in)? What I have is shooting great, but I wouldn't trust it as a knock around hunting round. I'm just wondering if anyone has some guidance re:how well a non crimped round holds together at the expected range of "neck tensions".
 

rfurman24

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What are you measuring inside necks with? I caliper will not give accurate readings. Two thousandths has a very slight resistance when seating and should not move once seated without some excessive force.
 

wind gypsy

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All of my hunting ammo is loaded with 2-3 thousands of neck tension (necks O.D. measure 0.002 - 0.003" smaller prior to seating bullet) and I have not worried about it. I haven't thought about it much just pushed on them a harder than I suspect they will be in recoil and verify it didn't impact seating depth.

Leave a couple in the magazine for an entire range session and measure them after if you're worried about it.
 

HellsCanyon

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if the neck INSIDE is sized to .002 below bullet diameter, how much grab is there?

Just to clarify.... you're measuring the inside of your neck to bullet diameter -.002"??
Don't measure the inside diameter of your brass, measure the OD of the neck after sizing, and then measure it again after seating a bullet. That will tell you what your actual neck tension is. With .001"-.002" neck tension you will have a very hard time pushing bullets deeper into the case by hand. When I turn the ID of case necks making hornady OAL gauges, it will only take about .0004" of a difference between a snug grip on the bullet and it nearly falling through the neck.

Mike
 
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Tod osier

Tod osier

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Just to clarify.... you're measuring the inside of your neck to bullet diameter -.002"??
Don't measure the inside diameter of your brass, measure the OD of the neck after sizing, and then measure it again after seating a bullet. That will tell you what your actual neck tension is. With .001"-.002" neck tension you will have a very hard time pushing bullets deeper into the case by hand. When I turn the ID of case necks making hornady OAL gauges, it will only take about .0004" of a difference between a snug grip on the bullet and it nearly falling through the neck.

Mike

Excellent - thanks!
 
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