Neck turning questio

[Mulligan]

After firing my brass a few times it needs to be turned again. Is this normal?
I am using necked-up 6.5x284 Lapua brass in my .284 F-open rifle. I no longer have the clearance I started with and the donut is a bugger to get the mandrel past.
Accuracy wasn't what it should be, so I tested .003 to .008 clearance, .005 & .006 showed the most promise with accuracy coming back with the recut necks.
CW

 

[ImBIllT]

I don't think it's completely abnormal. I'm not sure how many shots .284 shooters tend to get before they encounter that. As far as donuts, one of the few things I like about the K&M turner, is the angled cutter. It allows you to cut a little into the shoulder without as much risk of cutting/shooting your necks off. That does seem to reduce/delay donut issues. I'm sure there are plenty of other neck turners with angled cutters too.

 

[tenring]

After firing my brass a few times it needs to be turned again. Is this normal?
I am using necked-up 6.5x284 Lapua brass in my .284 F-open rifle. I no longer have the clearance I started with and the donut is a bugger to get the mandrel past.
Accuracy wasn't what it should be, so I tested .003 to .008 clearance, .005 & .006 showed the most promise with accuracy coming back with the recut necks.
CW

How do you know the necks need to be re-turned? As long as you have .002-.005" clearance between chamber neck and brass neck, re-turning is not needed. Agree with using the K&M angled cutter to remove donuts.

 

[mikecr]

Normal when you're way over sizing your brass(creating donuts).

 

[Mulligan]

How do you know the necks need to be re-turned? As long as you have .002-.005" clearance between chamber neck and brass neck, re-turning is not needed. Agree with using the K&M angled cutter to remove donuts.

Accuracy started to degrade.
When I measured a loaded round I only had .002 clearance and they were originally cut for .003. The "extra" brass was from the shoulder to mid way up the neck. I was really amazed at how much brass it took off on the second pass. Additionally accuracy was back as soon as I recut it.
CW

 

[Mulligan]

Normal when you're way over sizing your brass(creating donuts).

I set the die to bump the shoulders back .002. Smith said the Redding dies are the right match for the reamer.
CW

 

[Shynloco]

Wondering if that problem is unique to the 6.5x284 caliber (because of the pressure generated)? Personally, I'd do whatever it takes to regain accuracy and to heck with opinions on the subject. But be careful to check the necks for cracking and the neck/shoulder junction for signs of weakness on a recut because you are taking off more brass. Hence you won't get as many reloads on your brass as before and failures are sure to come sooner.

Alex

 

[LCazador]

How much are you cutting into the shoulder? I've been shooting both 284 and 6.5/284 for 20 years now and I've never had an issue with donuts and I shoot some pretty stout loads. I cut a 32nd" onto the shoulder and never had the donut issue. Of course all of my chambers are cut to eliminate bullet contact with the shoulder/neck junction area. I use a pumkin turner.

 

[Mulligan]

How much are you cutting into the shoulder? I've been shooting both 284 and 6.5/284 for 20 years now and I've never had an issue with donuts and I shoot some pretty stout loads. I cut a 32nd" onto the shoulder and never had the donut issue. Of course all of my chambers are cut to eliminate bullet contact with the shoulder/neck junction area. I use a pumkin turner.

The donut formed right away, second firing. Hasn't been a issue as the bullet never gets close to it. When I went to re-turn the necks, the mandrel fought with that donut a bit. I believe it pushed some of the "extra" brass to the outside and it was removed with last turning. I use a Sinclair turner and cut into the shoulder, just enough to "hang" a nail on. Maybe that's not quite enough cut on the shoulder, I'm not sure how to measure it?

The issue was a decrease in accuracy, after measuring the "regular" stuff and working up different loads it became obvious I was missing something. I then checked neck clearance and seen it was less than the original spec I established. Returned the neck clearance and accuracy returned. Best part is I did a neck clearance test and this rifle appears to like a bit more clearance and accuracy is now a bit better.
CW

 

[LCazador]

The donut formed right away, second firing. Hasn't been a issue as the bullet never gets close to it. When I went to re-turn the necks, the mandrel fought with that donut a bit. I believe it pushed some of the "extra" brass to the outside and it was removed with last turning. I use a Sinclair turner and cut into the shoulder, just enough to "hang" a nail on. Maybe that's not quite enough cut on the shoulder, I'm not sure how to measure it?

The issue was a decrease in accuracy, after measuring the "regular" stuff and working up different loads it became obvious I was missing something. I then checked neck clearance and seen it was less than the original spec I established. Returned the neck clearance and accuracy returned. Best part is I did a neck clearance test and this rifle appears to like a bit more clearance and accuracy is now a bit better.
CW

Brass will flow forward and if there isn't a place for it to go it's going to increase the thickness of the neck and shoulder junction. If you do it the same way you're going to get the same thing going on next time. Try cutting a bit more into the shoulder so you can have some room for the brass to flow without causing a donut.

 

[mikecr]

Brass doesn't 'flow' anywhere..
It's moved right where we put it -through sizing cycles.

I have neck turned cases with over 100 reload cycles that have zero donut formation, because I do not FL size these cases. I haven't moved brass thick toward thin, webs toward case mouths, with sizing.
And with this, it should be obvious that I don't have to trim away consistent case capacity either. It stays right there.