Neck Turning Part Five, Seating

[bikemutt]

I've always found virgin Lapua 6.5 Creedmoor brass to be kind of wild when seating bullets, with or without lube. The pull stroke on the arbor press always feels choppy, and the force required is all over the place.

I primed and charged these OD/ID turned and Neolubed cases today. Frankly, I was expecting a tighter set of curves but, it is what it is. It's much tighter than I've experienced with unturned virgin brass, so there's that.

Here's a picture, warts and all:



Filtered to 1 Standard Deviation of Work required to seat, 21 pieces survive, 13 don't:



We'll see how it goes tomorrow, range time 

[jvw2008]

Chris what was your final neck wall thickness after turning?
13 thou is what I'm remembering. Is that correct?

Second question: did you anneal after turning?

[bikemutt]

Chris what was your final neck wall thickness after turning?
13 thou is what I'm remembering. Is that correct?

Second question: did you anneal after turning?

Jerry, final neck wall is 12.5 thou, I did not anneal after turning, probably should have 

[DHuffman]

Jerry, final neck wall is 12.5 thou, I did not anneal after turning, probably should have 

The only time I anneal is after trimming or turning. I've been told by people who own hardness testing equipment that turning necks hardens to the equivalent of many firings.

To add, these high speed trimmers many of us use now likely have the same effect.

[jvw2008]

To get more consistent seating pressures I would suggest getting your neck wall thickness down to 12 or a tiny bit below and anneal always after turning.

I'm anxious to see how your recently turned rounds group.

[bikemutt]

I'm tempted to pull these bullets, probably not worth the effort, I'll just park this one in the "lesson learned" spot.

I think once they have been fired, then fully processed, including annealing, they should smooth out.

[bikemutt]

To get more consistent seating pressures I would suggest getting your neck wall thickness down to 12 or a tiny bit below and anneal always after turning.

I'm anxious to see how your recently turned rounds group.

What I found in my previously outside-only turned brass is taking the neck walls below 12.5 thou-ish drops the seating force plateau down in the 20's, I'd really like to see them square in the 30's. What I'll do in this situation is shoot them, fully prep them, then seat them. If they are till above where I like them to be, I'll turn them down a bit more. I don't have any other lathe work in the pipeline now, I'll leave the holder installed.

[DHuffman]

What I found in my previously outside-only turned brass is taking the neck walls below 12.5 thou-ish drops the seating force plateau down in the 20's, I'd really like to see them square in the 30's. What I'll do in this situation is shoot them, fully prep them, then seat them. If they are till above where I like them to be, I'll turn them down a bit more. I don't have any other lathe work in the pipeline now, I'll leave the holder installed.

Not sure what you are doing "post" neolube but I'm getting better/more consistent grip if I nylon neck brush my neolubed necks before throwing powder and seating bullets.

[bikemutt]

Not sure what you are doing "post" neolube but I'm getting better/more consistent grip if I nylon neck brush my neolubed necks before throwing powder and seating bullets.

How stiff on the bristles? Or better yet, which brand and model please?

[jvw2008]

The IOSSO brush is what I use. Not sure about Dave. Their blue brush is very stiff so it doesn't take a lot passes.

[gman47564]

Elasticity yield point.. I wonder how thin you can go with brass before it loses its Elasticity.. and just stretches.. any body know.. I would think .012or less would be pushing its limits.. but I don't know that.. I have to believe brass with a .012 neck thickness and .002 neck tension has less bullet grip as a .013 neck thickness and .002 neck tension.. I understand you tune to what you have but where does thickness start to yield

[DHuffman]

How stiff on the bristles? Or better yet, which brand and model please?

Not sure the brand, think it's a regular RCBS neck brush that has/had clearish bristles.
Run it on a Lyman rotary tool. Push it down over the spinning brush then pull off.
So far it's as close as I've come to getting as much of the lube out and enhancing grip while maintaining seating consistentcy.

[DHuffman]

Elasticity yield point.. I wonder how thin you can go with brass before it loses its Elasticity.. and just stretches.. any body know.. I would think .012or less would be pushing its limits.. but I don't know that.. I have to believe brass with a .012 neck thickness and .002 neck tension has less bullet grip as a .013 neck thickness and .002 neck tension.. I understand you tune to what you have but where does thickness start to yield

I routinely turned to .0105" and recently moved back up to .011" with plenty of what you're talking about. This is on a .268" neck chamber.

I've regularly seen .264" neck 6mm reamers for sale so would have to assume these require a .009" neck so again would have to assume that is still "holding a bullet" but don't know that from experience.

[jvw2008]

Elasticity yield point.. I wonder how thin you can go with brass before it loses its Elasticity.. and just stretches.. any body know.. I would think .012or less would be pushing its limits.. but I don't know that.. I have to believe brass with a .012 neck thickness and .002 neck tension has less bullet grip as a .013 neck thickness and .002 neck tension.. I understand you tune to what you have but where does thickness start to yield

Grant I think you are right on with that question. I don't know where the break point is and I suspect it may change with the caliber of the bullet. However, if the question is "can brass that is too thin loose its gripe", I will toss out another question: " can too much lube defeat the benefit of neck tension"?

[DHuffman]

Grant I think you are right on with that question. I don't know where the break point is and I suspect it may change with the caliber of the bullet. However, if the question is "can brass that is too thin loose its gripe", I will toss out another question: " can too much lube defeat the benefit of neck tension"?

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.