6xc brass question

[ctrickett]

I have some Norma 6xc brass with about 7-8 loading, primer pockets are still good, but after sizing brass f/l and bumping shoulder about 2 thou, seat bullet the bolt does not close easy. Seems like there is a small donut at the base of the neck( inside) which causes the neck to expand, making the bolt real tight to close.

So is this common in (maybe) older brass, or is this something that happens typically

Thanks for any help

Charlie

 

[rcw3]

When new, the shoulder metal of the Norma 6XC brass is thicker than the neck metal and as you fire cases, unfortunately some of that shoulder metal grows up into the base of the neck area and makes a "donut". Whether this is the source of your issue or not I don't know but it can lead to there being a heck of a donut there.

The other circumstance I know of is that the Norma 6XC brass was made more off a .243 Win base than the 22/250 base that the 6XC cartridge was originally designed from and many of the 6XC chambers are too tight at the base and after cases are fired multiple times, some bind up at the base and some sizing dies cannot resize the brass enough at the base because the web is just too big and there's too much spring back. There is a 6XC II chamber out there that has a more generous base dimension to accommodate this problem.

 

[spclark]

All of what rcw3 wrote is true enough.

In fact there have been several iterations on 6XC chamber dimensions since the cartridge first appeared for general use several years back.

One recourse to "tight base" chambers causing fired brass to chamber with effort is to use a small-base 308 sizing die to maintain control of case web diameter.

For that donut you can either set yourself up to inside-ream case necks with the proper tooling (I prefer Wilson products as that's what I already use to trim & square case necks) or cut a little bit of the shoulder brass away when neck turning so what migrates forward to form a donut gets thinned out before it can do so.

As good as the Norma brass is it's still not perfect & needs a little finesse to work well over time.

 

[mikecr]

The donut is caused by your FL sizing. That's how you're putting brass there.

 

[Mudcat]

another reason I use Winchester brass.....no donuts.....ever. With Lapua 22-250, you will get donuts as well. Have had too much trouble with the norma stuff to use it or the tubb stuff in matches. practice, yes, matches no.

 

[WyleWD]

There is a multitude of possible issues and combinations of issues that may have caused this. How hot you load, how your chamber was cut, the difference in size between your chamber and the resizing die, no turn neck vs turned neck, just to name a few. Also, you might double check to make sure that your primers are seated properly..... I've seen this cause difficult bolt close on occasion. So be prepared to look at several factors rather than just "blame the brass".

My 6xc Norma brass has at least 12 firings on the cases and are still competitive and functional. As a point of reference only.... I neck size and bump the shoulder after each firing... my Norma brass has never been through a FL die. WD

 

[ctrickett]

Thank you all, good info...I will do exploring. For the foreseeable future we shoot the 6xc as prone guns only. Our load has been Norma brass, 210m primers, 39.0 of H4350, 115 DTAC bullet, there are no pressure signs.

Mudcat, are you starting with 22-250 brass?

We are shooting 2 different rifles, from 2 different smiths....I didn't realize that more than one chamber was available. I do use different sizing dies to control sizing for each chamber

 

[Mudcat]

Mudcat, are you starting with 22-250 brass?

We are shooting 2 different rifles, from 2 different smiths....I didn't realize that more than one chamber was available. I do use different sizing dies to control sizing for each chamber

Yes. With Win, no donuts, with Lapua, donuts. I use the Lapua in my prone only rifles (no rapid fire use) and have my bbls throated long enough to avoid seating into the donut.

I have also noted that even with the same bbls by the same smith (WOA Wilsons) I get sizing issues between rifles. Yeah, its only a thousandths or so, but over time, its stretching the brass when they get used in several rifle/bbl combos. Not sure how many firings I am losing, as most of the brass is still going, so I havent really worried about it. BUT, for rapid fire use, I have to be careful to size the brass to the rifle its going to be used in. Would be easy enough to just knock the shoulder back a bit more, but that speeds up the stretch.

 

[james pope]

I have some Norma 6xc brass with about 7-8 loading, primer pockets are still good, but after sizing brass f/l and bumping shoulder about 2 thou, seat bullet the bolt does not close easy. Seems like there is a small donut at the base of the neck( inside) which causes the neck to expand, making the bolt real tight to close.

So is this common in (maybe) older brass, or is this something that happens typically

Thanks for any help

Charlie

I have some Norma 6xc brass with about 7-8 loading, primer pockets are still good, but after sizing brass f/l and bumping shoulder about 2 thou, seat bullet the bolt does not close easy. Seems like there is a small donut at the base of the neck( inside) which causes the neck to expand, making the bolt real tight to close.

So is this common in (maybe) older brass, or is this something that happens typically

Thanks for any help

Charlie

at least the case doesn’t separate after 3 reloads like the new Norma brass does. I am using Norma brass from Tubb and the base separates or cracks when 115 dtac’s are loaded 39.6 GR h4350@ 2950 FPS. Anybody having the same problem?

 

[lee1982]

at least the case doesn’t separate after 3 reloads like the new Norma brass does. I am using Norma brass from Tubb and the base separates or cracks when 115 dtac’s are loaded 39.6 GR h4350@ 2950 FPS. Anybody having the same problem?

How much are you bumping the shoulder back? Which chamber do you have?

 

[DTubb]

at least the case doesn’t separate after 3 reloads like the new Norma brass does. I am using Norma brass from Tubb and the base separates or cracks when 115 dtac’s are loaded 39.6 GR h4350@ 2950 FPS. Anybody having the same problem?

you have a headspace problem..

 

[Deton8tor]

at least the case doesn’t separate after 3 reloads like the new Norma brass does. I am using Norma brass from Tubb and the base separates or cracks when 115 dtac’s are loaded 39.6 GR h4350@ 2950 FPS. Anybody having the same problem?

I have been using Tubb brass in my XC for over a year, same lot. I do not have case head separation issues as described above. You have a headspace issue if you get 3 firings and a rupture. Additionally, I shoot 105-108's with the same charge being used with 115's, which may add to the problem. I would be doing some tolerance checking.

 

[rcol317]

you have a headspace problem..

Take note! I've been shooting DTubb and Norma brass since they've been available in a number of 6 XC's and have not had your experience.

 

[accuracyman]

I shoot Norma brass purchased from Mr. Tubb in three different rifles and have never experienced any issue with the brass. I find the brass to be very uniform and of the highest quality. It have noticed a donut like a lot of different brands of brass but if your reamer is designed properly for the bullet you intend to shoot then you stay away from the neck/shoulder junction. With 105 Berger VLD's you will need at least .100" freebore preferably more and around .150" to .160" freebore for the Berger 115's or DTAC.

 

[Frankr]

this is kind of a old thread. for the OP I hope he got it figured out. My buddy was telling me about a guy having a similar issue that his cases were bolting hard and they could not figure out why and he found the problem you will never guess what it was..I diden't .. he never cleaned his primer pockets and after he sized them they chambered ok then he primed them loaded them now they went in hard.. his dirty primer pockets were causing the primer to stick up slightly and that caused them to bolt in hard...Hard to believe... I always clean mine so I never ran into anything like that actually I never run into weird problems like that I learned long ago weird problem get rid of it. . I had a 22PPC once first firing was in a hole, next firing not so good 3rd and 4th firing shot gun. we found the necks thickened after firing..So we got rid of the brass and a new chamber. then I had a 6 dasher and I experienced the same thing the necks would thicken after firing sent it down the road.. dont know what causes weird things to happen like that. But I run a tight 6XC chamber with a tight neck and .104 FB and been shooting HOT loads on Norma brass for years never had a problem. I had the 6XC II chamber and also never had a problem..