Neck Turning Part Five, Seating

[jvw2008]

"I still say the best uniformer in spite of all the tricks we throw out there is the expander mandrel."

Yep, that's a basic step in my mind. The rest are tweeks.

[bikemutt]

I know this is splitting hairs but, what I'd like to have is for the center of the curves move up from the red circle to the blue circle. This was the 14th seating for these outside turned pieces, they run closer to 12 thou neck wall than the 12.5 thou. I think if I stay closer to 12.5 thou, I'll get my wish.

[bikemutt]

I haven't done the math on this but, the more we take off the neck wall, the more careful we have to be with the shoulder cut. Having examined some cross-sectioned brass, it's a fine line at that neck-shoulder junction, wouldn't take much to overcut the junction and weaken the neck.

[DHuffman]

I haven't done the math on this but, the more we take off the neck wall, the more careful we have to be with the shoulder cut. Having examined some cross-sectioned brass, it's a fine line at that neck-shoulder junction, wouldn't take much to overcut the junction and weaken the neck.

I think brushing the neolube out will get you there or closer to your seating pressure goal.
You are correct about the cut into the shoulder. I shot the neck off one years ago from getting into the shoulder too deep.
When turning 30° Lapua 6 BR to FF to BRA it's easy to go too far with a 30° cutter but a 40° cutter leaves a nicer feathered edge. It's not as crisp or clean around the shoulder but the transition is better and I've never shot one off doing it that way.

[bikemutt]

Shooting these will have to wait a bit, darn gout flareup 

[bikemutt]

Got this batch ready for tomorrow.

From what I can tell, both with seating feel and gage equipment, annealing the brass smoothed things out. Not earth-shattering but the number of cartridges inside 1 standard deviation of seating Work increased to 25 out of 34 from 21 out of 35. Plus, I did not lube these necks, nor the bullets.

I didn't post the target from the first firing because I changed way too many things; new muzzle brake, new rear rest, I was an on-duty RSO, etc. We are allowed to shoot if things are slow, which was the case. I spent more time adjusting scope turrets than shooting  . In any event, the largest measured 5-shot group at 300 yards was .84 MOA, the best was .34 MOA.

I'm on-duty tomorrow, I'll see how this first reload looks if things stay quiet.

[DHuffman]

Chris I've got a set of used Norma 6 BR Norma I bought last fall.
I bought a set of 450+ cases that were "once fired" LOL not turned LOL for $150

I wanted a set of brass I could shoot the occasional PRS match with and not crawl around on my hands and knees  hunting for those last one or two pieces of precious Lapua brass from a 10 shot string holding up the match. Just pick up what I could find quickly and walk on you know.

Out of 450 Norma cases there were 85 Lapua so I sorted them off.
Then I thought I ought to check the necks because some were obviously turned   they were everywhere from .008" on a few with a bell curve up to .014"
So I sorted them.
There was a Lapua .220 Russian that had been formed to 6ppc, I've always wanted to see one in real life so win win.
About a dozen R-P 6br Remington's
Maybe another 4 or 5 random cartridges that I sorted off.

Wound up with 250+/- of the Normas so I'm thinking I'm still way ahead on this deal not even counting the bonus 85 Lapuas right!

Start measuring shoulders on the Normas and WTF about 40% are about .010" short  not counting the shoulder bump. Decide to load about 20 of them and see if they'll blow back out without separating and the primer pockets are toast on about 90% of them so in the junk brass bucket they go.

So now I'm working a load up in the 160ish that were the right length for my chamber, some pockets are like new, most are just good and about 7-10% of are junk so far.

So I grab the 85 bonus Lapuas, everyone knows they've got much stronger pockets so I measure the shoulders and get the same .010" short not including a shoulder bump on about half of them and toss about 40 of them in the bucket.

So what I'm getting at is you are wasting your talents working on that nice brass so I'll send you this set so you can really hone your skills. How about it?

I'm going to cycle through that 160ish pieces and see how many pockets I lose just to satisfy my curiosity I guess. If I've got 100 pieces left I'll shoot a PRS match and not pick up a damn one LOL leave em' lay where they land.
Unless you want them of course.

[bikemutt]

You ever have "one of those days"?

I felt as if the rifle was fighting me, just could not get a dead-steady hold on the target. Turns out the picatinny rail mounted Atlas bipod had come loose which rendered the cant control useless. I finally discovered this before the last group and did my best to fix it, more work needed.

Meteorologically, the weather was unstable, very windy, rain, sunshine, 45F or so ambient temperature.

Excuses aside, the target is the final arbiter, could've been worse 

From a mission standpoint, I don't feel that turning these necks outside and inside made a mess of things, nor do I see fame and fortune in my future, lol. I did learn not to take adjustable components like a bipod for granted that, just because I locked it in once, it will stay like that forever, that was chump on my part.


 

[bikemutt]

I have a mea culpa to come clean on: The printer I use for my targets is a new Brother laser, it replaced a Samsung laser that passed away after many years of service. Unbeknownst to me, the new printer does not allow for tight border margins, it just changes the scale of what actually prints on the page, in other words, an inch is not an inch  . When I posted my last target I assumed each grid on the page was in fact 1"x1", nope, more like 0.95866"x0.95866". Because of the way MOA calculations are made, some targets had higher MOAs, some lower, not by much but enough to p*ss me off  .

Anyway, mistakes happen, lesson learned, "trust but verify", "measure twice, cut once" and so on, lol.

[jvw2008]

"From a mission standpoint, I don't feel that turning these necks outside and inside made a mess of things, nor do I see fame and fortune in my future,"

Chris I am definitely seeing progressive improvement in your groups. Sub o.4 MOA at 300 yds is nothing to sneeze at.👍
I'm willing to bet that at least part of that is better brass prep.

[bikemutt]

Yes and absolutely yes but as Grant pointed out and I agree almost any condition of neck tension, lube or grip can be tuned to an optimum within those conditions.

I still say the best uniformer in spite of all the tricks we throw out there is the expander mandrel.

When I seated this last batch of brass, your words rang a bell.

Both 6.5 Creedmoor seatings shown below were prepped the same; the main points being body sized, necks brushed inside, annealed and neck sized with a Lee collet die. The first one was the second time fired, the second one will be the 3rd time fired. No lube used when seating. Frankly, I was surprised when I seated these, I figured it would be more like the prior seating. The chart shows what I felt; more force required then it just gave up, the press handle slammed to the bottom of the stroke. Here's the charts composite.



I marked both seating charts with a vertical red line at the point where the neck "gives in" and the force required to complete the seating begins to fall. Most normal humans measure distance in things like inches and millimeters but, there's the odd duck who measures distance in ticks, not the insect type, rather the discreet numerology of rotary encoders. The red line more or less centers on 1120 ticks which translates to 0.248". Lets see where 0.248" is on the neck:



No surprise, the seating force falls off where the neck ends. What I find fascinating is the instant the bullet runs out of NEW neck carbon, it gives up the fight, quickly. It makes me wonder if I'd expanded the neck first, say with a Porter Precision die, to .264, then neck sized again with my Lee collet, would I have taken the fight out of the neck carbon, and have a more consistent seating result?

If neck carbon is really a natural lube, I'm not seeing it here but it's a small sample and the reality is the batch shows lower ES and SD than the second seating, as indicated by the blue arrows.

Hoping to shoot these Wednesday if the monsoon weather here cooperates, then it's off to the next Glamping trip to Astoria, OR 

[gman47564]

Question for ya chris.. did you brush the necks before or after annealing

[bikemutt]

Question for ya chris.. did you brush the necks before or after annealing

Yessir, both brushed

[DHuffman]

This falls straight into the "we all have our own way to do it category"

If I'm annealing it's probably because I'm trimming.
If I'm trimming I process the case and size it, trim it THEN anneal it. Trimming and turning brass hardens it rapidly from what I've been told by people with an AMP and a hardness tester.

Basically I

Decap, chamfer, debur & brush neck.
Uniform primer pocket and clean neck and shoulder.
Wipe brass with alcohol on a rag.
Size brass

Trim or turn if applicable
Anneal if applicable

At this point if I trimmed, turned and or annealed I will at the least re lube the necks and at most also neck size the brass.

Prime brass, brush neck, throw powder etc.

Some of you are going to say OMG I'm not doing all that and honestly it's not that bad and I guarantee it's way faster than a trip or two through the tumbler and I realize some of you are getting your neck consistency through the tumbler.

As much as a mandrel is the ultimate uniformer in neck sizing the brush is the great uniformer in seating consistentcy.

Get the size and consistency the same and you're in easy street.

Different size and consistency requires a different tune.
Say a .242 mandrel on One Shot lubed necks vs a .241 mandrel on Neolube necks vs a .2415 mandrel on no lube necks.

They have all tuned up and shot small in my experience.

[bikemutt]

I took a different tack data-wise; since I tracked these rounds as individual specimens, I decided to take a look at the trees, rather then the forest.

It was a bit tedious to step through each round's 2nd seating and compare it to the same round's 3rd seating, but, I'm retired  .

The carbon accumulation in the neck between firings clearly changed the seating force profile in aggregate as we observed in the previously posted seating charts. Individually, the change becomes more obvious I think. The composite graph shown below steps through each round's seating force for the 2nd and 3rd seating.

Depending on how this seating shows up on paper, I may be inclined to repeat the brass prep protocol to see if the change accelerates, reverts or holds steady.

https://drive.google.com/file/d/17-4h3JZmeH4nw6U4RELqYx8--lpfJBTS/view?usp=drive_link