Shoulder setback readings/Lee CC Turret press; Seating depth variance.

[stubbicatt]

Good Day: I've been working through my present reloading setup in anticipation of perhaps shooting F/TR later this summer. In preparation, I dusted off my old Lee Classic Cast Turret press, and began by resizing a few cartridges in attempt to set the shoulders back properly. I learned a lot of things, and I jotted down a few questions that arose.

I'm using a RCBS X Die, which I really like, a RCBS shell holder, and Lapua brass in 308 cal.

Unsized brand new brass measured out at 3.637 to 3.629 inches at the shoulder using the Stoney Point Comparator, insert numbered ".400."

Fired brass, not resized, was consistently 3.628 inches.

My resized cases, from dinking about with die adjustments, came in between 3.626 and 3.629". I had rather expected better consistency in the as sized brass. Which got me to thinking, what would lead to such inconsistency?

I had three theories about this .003" variance, and thought I'd seek validation of the theories, assuming that you guys are getting tighter readings in your setups.

1. The turret press maybe flexes enough to give the .003" variation in shoulder setback.
2. The X die acting on case necks imparts different shoulder setback.
3. The expander ball, me not having lubed the insides of the necks, pulling on the necks, pulled the shoulders forward for longer readings.

-There may be other answers as well, but these are the ideas I came up with.

Possible fixes/responses I came up with to my theories:

1. I no longer have an "O" type press, having gifted my Redding press to my son to initiate his interest in this hobby, so I cannot compare my results in the turret press to such a more rigid press at this time.

2. Not willing at this time to ditch the X die to see if a different arrangement works better. However, if necessary, I can ditch the expander ball and use a Lyman "M" die to expand and flare the necks to accept a bullet, after "outside" resizing.

3. Next time I size the cases, I will lube the insides of the necks to avoid expander ball screech, and perhaps level things out.

Thanks guys for helping me think this through.

Second Observation:

I am really pleased how well the Lee seater die works in this application, seating either 155 Scenars or 175 SMK bullets. In the case of the 175 SMK, measured at the ogive with the Stoney Point Comparator, the ogives measured out at a low of 3.248 and a high of 3.252. The 155 Scenars came in at 3.198 to 3.201".

This is a .003 to .004" variance in seating depth. Again, I do not know how uniform this measurement should be, i.e. are you guys getting more consistent seating depths with your setups? Or is this about what one can expect?

Thanks for your experiences and suggestions in advance.

Regards,
Stubb.

 

[Rule3]

Well beyond my pay pay grade.
Do you have an instrument that is truly capable of measuring .003 constantly. The width of a hair?

 

[243winxb]

The .003" is not bad at all for your set up. The shell holder must make full contact with the FL die to get the best shoulder bump control. But this may push the shoulder back more than you want. The fix is Redding Competition Shellholder Set #1. http://www.midwayusa.com/product/525874/redding-competition-shellholder-set-1-308-winchester-30-06-springfield-45-acp

came in between 3.626 and 3.629"

You mean 1. ??

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[fguffey]

Stubbicat,

http://www.saami.org/PubResources/CC_Drawings/Rifle/308 Winchester.pdf

http://www.saami.org/PubResources/CC_Drawings/Rifle/30-06 Springfield.pdf

When making reference to variation the variations for the 308 Winchester would be somewhere near or around 1.634 then there is that – factor, I pick 308 W because of the .400” reference, assuming the .400” is the datum.

If we are takljing about 30/06 the +/- factor would be to either side of 2.052 with a reference to the datum being .375. If you are not making reference to case length from the datum to the head of the case save your money on the redding competition shell holders, I do everything (+ more) the Redding shell holders do with a feeler gage, again, I form cases for short chambers, I form cases for long chambers, that would include short cases from .012” shorter than full length sized to infinity. I know, it is believed the press and die can not alight without making contact between the shell holder and bottom of the die, my cases have case heads, my case heads are from .200” thick to .260” thick, that is well above the deck height of the shell holder of .125”.

But let us say you can use the Competition shell holders, I had rather determine if I need them over purchasing them only to decide I do not need them, the 30/06 shell holder cover many applications, again, I have done OK without them. For me it has never been necessary to grind the tip of the shell holder or bottom of the die nor has it been necessary to purchase another set of shell holders.

I do have a #6 set, I could not pass them up, $5.00. I formed 200 + cases for a friend, he needed magnum wildcats formed from 8mm Remington, 300 Weatherby etc. cases. Just my luck, with all those expensive shell holders I had to back the forming die off .190”

F. Guffey

 

[HJ857]

Definitely put a bit of lube inside the neck, for exactly the reason you've said.

Also, on the fired brass, there's a chance the rims are not square, especially if fired from an autoloader. That will definitely throw off your measurements if using the Hornady comparator. If you spin the case 45 degrees and re-measure and your measurement changes, then it's likely the rim.

It may be useful to use a case gauge such as this one, rim deformation doesn't come into play, or at least you can visually see if the rim is bent if one side of the case is flush with the gauge and the other side is above the gauge. http://www.grafs.com/retail/catalog/product/productId/23851

I like the comparator better because it gives hard numbers and use it to set up the sizing die. But sometimes the brass confuses the comparator and that's when the gauge is most useful to figure out if brass is being difficult. I rarely adjust the sizing die, but sometimes do run a piece of brass through the die two or three times if measurements go wonky. I also use the LCT press.

 

[stubbicatt]

Dang guys for all that I forgot to say it is a 308. Keeripes. Also, all cases fired in a CZ 550, bolt actioned, CRF, rifle.