Neck tension - Brass Question

[Jowens]

Ok I am having some issues with reloaded brass on my .284 win

New winchester brass, run through whidden die with a .311 bushing and expander to fix any dented casemouths. Neck OD measures .311.

Once fired brass, tumbled in stainless pins, annealed, then ran through the die with no expander. Brass ends up .310 OD. Once fired brass after this process equals super smooth and easy bullet seating. The new brass requires much more force.

The once fired cases shoot terribly compared to the new brass. I feel like the new brass must have more grip on the bullet since it is harder to seat the bullet.

Anyone have any ideas? What steps do I need to take to get my new brass accuracy with fired brass? Never had this issue before.

 

[noload]

If I undersand your post, I think you are saying fresh annealed brass doses not shoot as good as New Brass.
I just read someones post tonight saying he was getting better groups with brass fired a few times after annealed, as opposed to fresh annealed brass. I also think annealing is a necessary evil when it comes to that. I have found there is no guarantee that fresh annealed brass will shoot as good as couple times fired brass. My 284 Shehane responds better to annealing than does my 6br. Its possible you are not alone concerning this. I haven't figured out how to deal with this myself. The groups I get from fresh annealed brass are good enough to work with but not quite as good as a few fires on it. :-\

 

[DickE]

No expert here but I'd like to know how your concentricity is. Did you chamfer the inside and outside of the mouth of the case?

 

[Jowens]

I was hoping it had to do with the seating pressure difference Im seeing between the two, which could be annealing related? I was hoping I could increase neck tension with a smaller bushing and get back to my new brass accuracy.

 

[Jowens]

Yes, chamfered on both inside and outside when brass was new, but not again for second firing.

On a NECO gage my loaded round is .002 or less.

 

[coford]

Two things come to mind.

Have you tried a smaller bushing to give you more neck tension? My .284 shoots better with about .002 neck tension. I've tried less but did not have as good a luck with it.

Is there a chance that you over heated your necks and made them too soft?

Also - just out of curiosity - did you turn your necks - what is the thickness of your brass - what size is your neck diameter in your chamber - what is the neck diameter of a loaded round?

 

[skiutah02]

I had (I think) a similar situation. In virgin lapua brass, I developed a "great" load. Neck OD on new brass .248, loaded (unturned) was .250. It shot great. I had to pull a few rounds from the virgin brass, and the brass had a death grip on the bullet even though only 0.002 neck tension. Ended up ruining the bullet(s) to get it out of there with a collet puller. Seemed strange. When I went to reload my 1x fired brass, I used a .248 bushing to get back to same neck OD. Measured and all seemed good. When I seated the bullet, I could immediately tell that it took less force.

When I shot it, the tight groups went away.

I played around (alot) and it was not until I went with a smaller bushing (.247) for 0.003 tension that I found my solution. Then small groups returned. I did have to change both powder charge and seating depth to get the best groups. I do not claim to understand this, but it seems that virgin lapua, right out of the box, seems to have a much tighter grip on the bullet even though OD is same. I know that many here work on their brass, but I only weight sorted and loaded it. I've moved to turning necks now, so I expand, etc.

 

[Joe Salt]

Skiutah02 One thing at a time! Now try putting Moly or something on the inside of the neck to give you easier seating, more consistent seating depth, and they will pull easier. Don't ever try seating bullets in dry necks it just galls the bullet. You must see that when you said you are ruining the bullet. I would also polish the inside of the neck with 0000 steel wool.

Joe Salt

 

[Jowens]

I haven't turned my necks.

I could have over annealed, I'm doing it with a torch and a drill. I've always done it with my .308 brass with no issues. I started off with templaque when I first started my .308 cases and could tell if I was there by the color of the case.

My loaded round is .313. I have a .311,.310 and .309 bushing. Ill try the two smaller bushings.

Maybe I should leave the carbon in the case and not stainless tumble as well.

 

[FatBoy]

I agree with one thing at a time. First step for me would be a .001" smaller bushing. If that doesn't work, then try changing something else.

 

[skiutah02]

Skiutah02 One thing at a time! Now try putting Moly or something on the inside of the neck to give you easier seating, more consistent seating depth, and they will pull easier. Don't ever try seating bullets in dry necks it just galls the bullet. You must see that when you said you are ruining the bullet. I would also polish the inside of the neck with 0000 steel wool.

Joe Salt

No sure what you are seeing, but I did do one thing at a time. Maybe you are misinterpreting what I wrote. The small group size returned with the 247 bushing, and I reduced the group size more by changing my powder/seating depth later once the barrel was broken in (saw a 30-40 fps increase in velocity after 150 rounds) and started using the fire-formed brass. Joe as you are following this post and my post about annealing/carbon in the neck, my observation about annealing/carbon came from trying to regain the accuracy of virgin brass. Thanks again, Drew

 

[Keith Glasscock]

From the experiments I've seen, super clean or new brass will be stickier to the bullet increasing the force needed to move the bullet. If you are tumbling only a reasonable time, the inside of the neck will still be "lubricated" slightly. I agree with above posters, more neck tension, and perhaps a little experimentation with the load to find the "fired brass" load.

I would also do a springback test on the brass. It is easy to over-anneal Winchester brass.

 

[Jowens]

Could someone give me the lowdown on the "spring back" test and how it's done

 

[jonbearman]

I use a pair of regular pliers and squeeze ever so gently to just see the brass move and if it doesn't spring back it is too soft for me.

 

[Joe Salt]

Drew yes I've been fooling your posts, if its the new brass thats the problem, Some rifles will shoot Virgin brass better than formed. My old buddy one-flyer, all he did was use new brass gets expensive but sometime you have to go with what works. But make sure you lube inside the neck every time.

Joe salt

 

[wapiti25]

I think getting the neck too clean is bad. I lube the necks with Imperial Dry Neck Lube, every time I load. Annealing does burn the carbon out of the neck or some of it.

 

[Shynloco]

Jowen,
I'm in the concentricty camp on this one. What I do with new brass, regardless of the make, I first fireform the brass and then turn every piece to make sure they are concentric. Now that turning process is just a light pass or two to make sure the brass is right. You might be surprised the variation of brass concentricty even with new brass as to the amount that is lightly shaved off from piece to piece. And the bite of the brass on the bullet needs to be even so the release of the bullet is allowing it to be concentric as it enters the barrel's rifling. And annealing won't help if your brass isn't right. That by the way is one just one factor in trying to find your best loads for a particular rifle. Just my take on it.

Alex