Outside neck turning Vs. inside neck reaming.

RBHarter

West Central AR
As I understand it ....... You ream thick necks and forming donuts .
You turn the outside to provide uniform thickness and better chamber centering of the neck .
 

RicinYakima

High Steppes of Eastern Washington
As I understand it ....... You ream thick necks and forming donuts .
You turn the outside to provide uniform thickness and better chamber centering of the neck .
Only if your reamer is too short, and your sizing die doesn't size to the shoulder.
 

RBHarter

West Central AR
Forming donuts ie; 8×57 to 7.65 ,7,or 257 where a neck is lengthened and the former neck shoulder jct is inside the neck , Savage cartridges from 308 family as another example ......the Mauser and Argentine may not have been the best examples maybe those from 06' is a better example .
 
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Fiddler

Active Member
Outside turning will uniform neck wall thickness, a reamer will follow the existing hole and you will still have some variation in wall thickness. The donut occurs when outside turning and you don't get all the way to the neck (not reaming all the way through would also create the donut). Not sure if it is a problem unless the base of the bullet goes that deep.
 

JWFilips

Well-Known Member
I only turn necks: On a bunch of cartridges it is mandatory because the throat requires bigger than spec bullets!
 

Ian

Notorious member
Outside turning a case neck that has a variation in thickness will result in the outside (as well as the inside) being eccentric with the case body. Annealing and fireforming without bumping the shoulder at all is the best scenario for getting things back in place.

Reaming doesn't fix neck wall thickness variation OR concentricity, but does a good job of clearing rings and donuts out of the neck prior to an outside turn, annealing, and fireforming.
 

RicinYakima

High Steppes of Eastern Washington
Ian, my solution, for match 30/06, to that was to FL resize in an LE Wilson old style die with an arbor press. Then remove the case and square the base in the trimmer. Then I fireform and measure for neck wall thickness. After turning, fire in the same chamber and it will be as close as possible on centerline of chamber, but not necessarily the bore. Every case only goes into one rifle. Ric
 

Petrol & Powder

Well-Known Member
From another thread but it fits here:

Outside neck turning is one of those operations that can result in huge improvements or almost no improvement at all, depending on the quality of the casing you start with.
Because few people take in account the starting point of the quality of the brass, you get mixed reports of value.
People that start with good brass don't see much improvement from neck turning and report that it isn't needed (and in their situation, they're correct)
People that start with less than ideal brass report huge improvements from neck turning. And of course they are correct too.

As Ian points out, it's a one time operation and after the first firing you end up with a great casing.

An inside reamer will simply follow the existing contours but after fire forming that may be sufficient to get you where you need to be.
Outside turning over a mandrel is probably a better operation to achieve the results you're after. With outside turning you are more likely to just take off the high spots. While fire forming may still be needed, you are more likely to end up with better uniformity of mouth thickness.
 

popper

Well-Known Member
I only turn converted 223 to BO. Good brass turns the entire neck, poor stuff has lopsided case wall.
 

L Ross

Well-Known Member
Ian, my solution, for match 30/06, to that was to FL resize in an LE Wilson old style die with an arbor press. Then remove the case and square the base in the trimmer. Then I fireform and measure for neck wall thickness. After turning, fire in the same chamber and it will be as close as possible on centerline of chamber, but not necessarily the bore. Every case only goes into one rifle. Ric
Was it worth the extra time and effort? And what do you mean, "Square the base in the trimmer"?
 
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RicinYakima

High Steppes of Eastern Washington
Was it worth the extra time and effort? And what do you mean, "Square the base in the trimmer"?
Was it worth it? Don't know for sure, but won three CBA National Military Rifle championships over the years with the same 400 case lot of brass.
On a Wilson or C&H case trimmer where the case is pushed into a metal sleeve for trimming, if you turn the case around the cutter will square the base of the case. Bases are not normally perpendicular to the case body, but are wavy or tilted or just not flat. I trim them back until about 20% of the base is aligned with the body. This usually only takes about .005 to .010", but you may have to fire form them once to set headspace.
 

Ian

Notorious member
I never thought of doing that, Ric, good idea. I have spent some time draw-filing burrs and nicks though during the great bullet lube adventure because chasing consistent true OAL drove me nuts.
 

RicinYakima

High Steppes of Eastern Washington
And there is so much slop in shell holders, there isn't a dimension to work off of with a seating die. That is how I ended up with a Vickerman seating die that is snug around the case neck, and with squared bases works pretty well.
 
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