2 Questions: brass(Nosler vs Lapau) and neck tension

[BrentM]

My first experience with custom Nosler brass is for my 204. I have been very happy with it. For my 6.5-284 rifles I have been using Lapua brass. However, I figured I would try Nosler custom for this new barrel and unfired brass was giving me very good results. Fire formed brass is not as good with the same load which has caused me to work up a new load. I noticed a little pressure signs with the same charge etc etc. Heavier bolt lift, little flattening of the primer, and very slight ejector marks.

Generally fire formed brass is the most accurate and consistent from what I have been able to tell. I typically body size with a Redding body die and bump the shoulder and bushing neck size .002 under loaded neck diameter. I use Federal match primers, same lot. I same lot everything during load development.

So the only thing I notice that is significantly different is neck tension. While seating a bullet in the new brass vs fired brass the tension is significant.

1. I have heard Nosler brass does not handle pressure as well as Lapau and there fore I may not be able to get to desired charge levels without seeing a bit of pressure. True or False?

2. Neck tension is generally believed to be best at .002. Is this still the correct rule of thumb?

 

[FearNoWind]

1. I have heard Nosler brass does not handle pressure as well as Lapau and there fore I may not be able to get to desired charge levels without seeing a bit of pressure. True or False?

2. Neck tension is generally believed to be best at .002. Is this still the correct rule of thumb?

1. Don't know where you heard that but keep in mind that internet forms are defined as places where facts suffer obfuscation and rumors enjoy proliferation.

2. In my shooting circles, neck tension somewhere between .001 and .002 is considered optimum for long range target shooting. I doubt that you'd find neck tension to be a major factor in long range hunting where your target is, figuratively speaking, about 8 - 10 inches.

If your having difficulty with controlling neck tension you may find it useful to turn the necks.

 

[Mikecr]

It shouldn't be a surprise that loads change from new to fireformed cases.
You'll have to do some measuring to lock in on a tension issue. In general, a couple sizing cycles of necks wouldn't cause significant change. Are you pre-expanding downsized necks before seating? Over-cleaning necks?
Measure cases overall, considering capacity.
Would you say there is a lot of body sizing happening here(new-vs-fired/sized)?

 

[BrentM]

fearnowind- yeah, I read on here when I bought the cases and asked a question about nosler brass. Neck tension is fine on fired brass. New brass has a lot more tension. I was hoping the info was not accurate as I like how nosler custom brass is very consistent.

Mikecr- I am not surprised the load changed a bit but I am dissapointed I am seeing a bit of pressure with the exact same load set up. I didn't expand the necks and then resize. Probably a good idea though as that would help reduce variation and set that process to more closely match the fired cases. Body sizing is normal and not excessive. fired case Head space is 1.840 and resized is 1.8375.

I have not tinkered with neck tension variations and have always gone .002 under. Never saw a need as my loads seemed to work well enough. Next range session I am going to play with a couple of loads that seem to work well and call it good.

 

[Timber338]

I have not shot Lapua brass, but I have used Nosler brass quite a bit and am also very happy with how consistent it is. I always start out with .002" of neck tension, except for one very light rifle with big recoil and I use .003". I have played around with .001", and overall I have not found any one neck tension that shoots better than the other. Overall I believe that .002" is the best place to start.

Out of curiosity, are you doing any kind of prep to the inside of the case necks? I always remove the powder residue with a light touch from steel wool wrapped around a smaller diameter bronze bore brush. Just run it in and out/twist until all of the residue is gone, then wipe the inside of the neck with a thin cloth and alcohol. All of the Nosler brass I have used has very consistent neck wall thickness, so no need to turn the necks. When I seat bullets it feels like they all seat into the neck with the same press force.

 

[BrentM]

The fired brass is no issue at all. It is smooth as butter. I was just comparing new brass to fired and the difference in tension. After running my brass through a vibration cleaner I may run a nylon case neck brush and some carbon remover with a drill. I have never had any issue with carbon on brass after cleaning though. I suppose for the best accuracy this should be done. Just been lazy with that piece of the equation.

 

[scottishkat]

So the only thing I notice that is significantly different is neck tension. While seating a bullet in the new brass vs fired brass the tension is significant.

1. I have heard Nosler brass does not handle pressure as well as Lapau and there fore I may not be able to get to desired charge levels without seeing a bit of pressure. True or False?

2. Neck tension is generally believed to be best at .002. Is this still the correct rule of thumb?[/QUOTE]

I would not think that a neck tension differential of .001 would make a significant pressure difference. Have you checked the case capacity of your Nosler brass which is made by Norma? Reduced case capacity would make a difference.

Generally speaking it has been my experience that Lapua brass has less case capacity than all others but there are differences batch to batch. You can try to weigh your brass once it has been trimmed and sized in the same manner. Or you can check the case capacity with water. Lesser case capacity will create higher pressures and high pressure symptoms with loads near max.

Also if you may notice higher velocities with a lesser charge because of said pressure differential.

Good luck and shoot straight. Especially with the 6.5x284.

Bob

 

[BrentM]

Measured new brass OD at .289 to .290. My bushing is a .292 and loaded cases are .294. I ran the expander ball through the cases and neck sized for roundness and uniformity. I use graphite powder to size to that will help the bullets ease into the cases a little better.

On another note, these are the groups I was refering too with a little bit of pressure signs. It was windy and not consistent so there is error both ways. I was trying to tune out the pressure and the best load with no pressure came out to .25 MOA, so a .5 inch group at 207 yards. It was pretty slow though. I think the tighter group was during a low in the wind and I shot as fast I could. I shot a lot of rounds so I can't recall exactly what the wind was doing but that is what my old brain remembers. I was out all day messing around with 2 rifles.

 

[bigngreen]

Nosler/Norma brass will not take the pressure the Lapua will, we always have to back of a load going from Lapua to Norma and give up a little velocity.

I would not hesitate to change neck tension from .002, if all the other normal things are covered and you feel a different seating force I would definitely change out bushings and see what happens. I've recently seen some very excellent bench rest shooting done and all with .004 neck tension which kind of opened my eyes to playing more aggressively with neck tension.

 

[BrentM]

I have .292, .291, .290, and .289 bushings. Been wondering if there is a relationship there but don't have the experience yet to know. Heck, it is still a chore to shoot bugholes at 200 for a guy like me.

On another note, what you said about the Nosler brass is what I recall reading too. It seems to be the case here as well. 56.5 grains retumbo is 2 grains under max load in the berger manual. I could go 57.5 with Lapau brass with similar pressure signs.