Neck tension, accuracy & you....

[fgw_in_fla]

You guys that are making shots into the next zip code, what's your preference on neck tension?

I just got all new mandrels for all of my NS dies. The previous mandrels gave me .0015+" to .002" on the neck. I thought I'd try .001" to see if I could tighten up on consistancy & lessen flyers.

Flyers are far & few but I still get an occasional one. I hate flyers.

In the past, I've tried the current neck tension spec and tighter, even as much as .004" so I thought I try going lighter. I know neck tension can only be so tight before the bullet sizes the neck when it's being pressed in...

I typically load one at a time when shooting from the bench. If we're out in the swamps, I 'spose recoil is a concern & may push the bullet in. I'll probably make tighter necks for that application.

Whatcha think?

Frank in FLa

[darkker]

Don't have any specs to give you, just my results.
I use Lee dies. Arguements for "tighter" tollerances and such aren't my driver in that choice.
My 308 1,000 yard loads using neck dies, never could quite do MOA at that distance. So I began playing with the FCD. What I ended-up happy with, was a very light crimp. This won't be that definitive, I grant you, but it is by feel; for me.
What I USED to do, was CRIMP. So I could feel the "squish" on the bullet. WAY WAY WAY to much!!, now I juuuust get to where I can feel the die contacting the case, with a VERY slight amount of crimp.

It took a bit of fooling around, then shooting. At this point that load is Under Sierra max load for Win 748, 175 SMK's and every headstamp under the sun. Runs about 2550fps at the muzzle, and easily holds MOA at 1,000.

Best of luck!!

[jhelmuth]

Frank...

Neck tension seems to be a deep subject and one I'm just getting to feel better about. So here is my synopsis...

[1] Neck tension is a critical factor in accuracy. Like ALL accuracy issues, consistency is the key.
[2] Consistent neck tension is affected by a few factors (and I may not be aware of all of them)...
- cleanliness of the inside of the neck at the bering surface
- concentricity/runout of the neck wall
- quality of the brass springyness (see annealing)
- proper and consistent neck sizing
[3] Neck preperation with respect to cleanliness as well as trim length and case mouth chamfering

If you combine all that with well preped and sorted brass, perfect charges, and excellent primer pockect prep and seating, you ought to have winner-winer-chicken-dinner hand loads.

Regarding the LEE dies... I will agree with darkker on the .308 Lee dies (I use them myself). Excellent dies for that cartridge, and never let anyone tell you otherwise (Lee gets a bad rap unjustly). I use the Lee .308 dies (less the FCD) for my competitive .308 loads and I get fantastic results with them (why fix what ain't broke?). However, I find that not ALL Lee dies are as great as the .308 dies. I also have the .223 Lee dies, and I feel the Redding and Forster dies are superior for this particular round (I like what Redding does with the neck bushings and I use their body dies too - I use Forster comp seating dies). My feeling is that Lee mkes some great dies - just not for all calibers/cartridges. YMMV.....

[fgw_in_fla]

I use Lee dies exclusively..... Have you seen my targets? Lee dies are great for what I use them for. I can even bump shoulders back after I've neck sized them 5 or 6 times. Nothing wrong with Lee stuff & I like their warranty.....

Anyway -

I'm not a competition shooter. I compete against the last time I visited the range.

My question, for all intents & purposes, is, what neck tension do you guys use?

I already practice everything you told me Jim...

I heard some of the 1000yd guys use .001" or less on the neck tension. I also heard a story (probably just that... a story) about a guy that seated his bullets long & set the length when he closed the bolt - ie, loose tension.

SO..... As I said in the top post, I've tried almost everything from .002" to .oo4" and tighter. I was wondering about the relationship between neck tension & flyers / accuracy.

I hate flyers....

I get them every so often & it's usually a round with a tight neck. I think.

Whatcha think on that?

Frank in Fla

[jhelmuth]

Sorry if I sounded vague (I guess it comes across that way when I understand what I'm saying, but fail to get the idea across). My point is that flyers are usually due to something that was NOT consistent in the load. So - with respect to neck tension (which I stated - superflously - was very important) it may be one of those factors. I always feel certain that I do ALL of those things really well and consistently - but the fliers tell me differently (after all.... I/we are human).

Now... more directly, I think neck tensions of 0.001 to 0.002 are best. But I'm NOT experienced enough to be that definative on that either. My experience is that some cartridges seem to require more/less and are more/less finiky. So I think we all have to do some experimenting on our loads and what works best in our rifle's chamber. But again... I think 0.001 to 0.002 works best in most instances.

[supergolfer18]

just quick question: Lee Dies what type of run out are you seeing with the different dies for the 308 win?

[jhelmuth]

For the cases I use (winchester), typically no more than about 0.001 - sometimes less and closer to zero. I measure on a machineist v-block set-up with a staret dial gauge.

[fgw_in_fla]

It sounds like you & I are at similar stages with reloading for max accuracy. I think it's an ongoing learning process. One that we'll probably never be happy with the results.
You tend to always think you can do better....

Golfer - I don't shoot .308. Yet, anyway. I think my next project will be a .308 although a 30.06 barrel with brake is high on the priority list.
As for runout, I use the "roll across the benchtop" method. If the tip doesn't wobble, in the front of the box. Wobblers go to the back of the box. I gotta admit, I've shot group that were pretty tight with the wobblers so I sometimes wonder if there isn't another factor that causes or helps cause inconsistantcies & flyers.
Frank in Fla

[jhelmuth]

Maybe I misunderstood the question - but I thought golfer was asking about neck runout. As far as bullet runout, I do not measure that so much, but I was getting about 0.003 (I'm reasonable sure my memory serves me correctly) on the bullet. I too use a visual roll test as I'm loading just as a quick-n-dirty reference. If I can't see it in the roll, I don't care to fix whatever it may be. As I am learning I feel that the results I get seem to imply that for the .308, bullet runout is not such a big deal if it is not visually detectable. I also think concentric and consistent necks minimize that too...

[acemisser]

whats minute of angle at a 1000 yards....?

[rjtfroggy]

Ace it is10. one minute per 100 yards.

[fgw_in_fla]

MOA should be the proportional to the shorter distance.... I think.


If you're getting .5 at 100yds, you can expect 1.0 at 200.....

[JackinSD]

whats minute of angle at a 1000 yards....?

Really?

[Blue Avenger]

MOA should be the proportional to the shorter distance.... I think.


If you're getting .5 at 100yds, you can expect 1.0 at 200.....

LOL How many have a 1000 yard MOA load that will not do moa at 100 yards? I know a couple do!

[lal357]

i started annealing my brass when flyers became more and more plus i could feel the difference when i was seating my heads after annealing them they feel the same seating them . i use a bushing die on my 308 and 223 and i play around with the neck tension that way and see what effect it has on the groups. another thing i do for my match load is run them thru my hornady concentricity guage and staighten out any run out i worry more about it on my 6.5 creedmoor since i load them .120 off the lands and want the bullet as straight as possible when it hits the lands/bore.. my 223 likes the amax's with a resizing bushing .003 under (i measure the the thicknees of my brass and come up with that ) this winter i'm going to try neck turning my brass and see if it yields any better results i also will need it for my 6.5creemoor since i am going to start making/forming my own brass out of some other caliber(trying 22-250 right now tried 308 lapua's and have to take some of the necks to use.

[earl39]

whats minute of angle at a 1000 yards....?


If you are asking what size area does 1MOA cover at 1000 yards it is approximately 10 1/2 inches or 10.47 inches to be more precise.

[MZ5]

Maybe I missed the answer skimming this thread at high speed. In case not:
You can't get more than about 0.001 to perhaps 0.0015" of 'neck tension.' Sizing the neck smaller doesn't give more neck tension, it just means the bullet is resizing the neck as it's inserted. Both Redding and Lee will tell you that this is the 'optimal' neck tension, and to set your dies accordingly (there's a thousandth or so of spring-back from sizing, depending on thickness & hardness of the brass). Trying to get 'more' tension just increases cartridge runout. Cartridge runout may be the underlying cause of the flyers. Or brass hardness (tension). Or shooter error. Or little green men.
:)

[darkker]

LOL How many have a 1000 yard MOA load that will not do moa at 100 yards? I know a couple do!

My 1,000 yard load STINKS at 100 yards, but since that isn't where I'm shooting to; who cares!

[DanSavage]

My 1,000 yard load STINKS at 100 yards, but since that isn't where I'm shooting to; who cares!

Explain darkker, are your 100 yard groups like 2''-3''?

[fla9-40]

How are you guys measuring neck tension?

On my .223 I did a test over time on neck sizing and FL sizing to see if there was a difference. On all the test run, my FL sized brass was way more accurate then the neck sized brass. I do use the FCD on both...VERY little crimp. I know they say you are overworking the brass and it see's a short life span by FL sizing but I have read different so I go by... brass is cheap!

On my .308 I use the Redding Competition Seating die, and still need to do more testing on it to see if it has helped any.
I do know the run-out is slim to none now. I use the Horandy Concentricity Gage for the bullet run-out.