Sizing dilemma

[mousegunner]

Today I tried to resize 20 .308 cases shot out of my 40x. Put my Hornady die in my Rockchucker with the LNL bushing. Wanted to push back .002 but went back .005! Tried again same thing. O.k. so I adjusted the die out 1/16-1/32 of a turn now the case grew .004! Tried again and the case was longer. Cases were lubed and I resized without the expander to have that out of play.

I use the RCBS case mic and previously sized brass measured 0.0 on the mic. Had not changed anything on the dies. Checked the dies, the press, nothing wrong I can see.

I've resized a lot of brass for my 40x and .308 Garand with no problems, this has me stumped. I went through the 20 cases and couldn't quite dial it in like before. I'm gonna try some .223 tomorrow and see what happens since I don't have any fired .308 brass, it was just the batch of 20.

Ideas?

 

[nicholst55]

Same shell holder as before?

 

[mousegunner]

Same shell holder as before?

Yes.

 

[sqrlgtr]

your case is probably getting longer because your not bumping shoulder enough after backing die out.Have run into this before when brass gets work hardened and is not as springy ie,as die starts to squeeze body smaller it has to go somewhere so case grows longer.Just start turning die back in s little until you get desired bump.Hope this makes sense and helps..

 

[Ralph Littlefield]

I bet if more folks checked each case as they full length sized them, they would be surprised by the variation in headspace that they are getting. Lots of things can make a thousands or so difference, dirt on shell holder or case head, flex or wear in the press, different amount of force required due to variation in fired case size or brass hardness or amount of lube, variation in the time of stroke (time of pause at end of stroke) and probably more that we can not think of.

 

[243winxb]

adjusted the die out 1/16-1/32 of a turn

Where is F. Guffey, feeler gauge needed.

I would start with .005" gap between shell holder & bottom of die. Size case and count to 10 while at full up stroke. Adjust die down .002" at a time, if needed.
Do this till there is a lite crush fit when chambering a sized case. Bolt action only. Autos need slop/more head clearance.

Or buy a set of Redding Competition Shellholders & a RCBS press that cams over. But even with cam over, there will be a variation of 1 or 2 thousandths. Its the difference in light to hard cam over.
Then there is lube differences, that i know nothing about. Been using RCBS 2 lube only for years & a pad. No lube on the shoulders.

 

[dolek]

Try screwing your die in more, the brass will soon be going the right way . You already know it will bump the shoulder back .005" , so it just needs fine tuning to hit your goal of .002" .

 

[TC260]

I bet if more folks checked each case as they full length sized them, they would be surprised by the variation in headspace that they are getting. Lots of things can make a thousands or so difference, dirt on shell holder or case head, flex or wear in the press, different amount of force required due to variation in fired case size or brass hardness or amount of lube, variation in the time of stroke (time of pause at end of stroke) and probably more that we can not think of.

Been loading for 30 years, it's amazing how much better of a reloader I was before I had the tools to measure everything

 

[JFrank]

The case doesn’t have headspace

 

[dantiff2]

Do you anneal your brass? If not, what a difference it makes with consistent shoulder bumps!! ; )

 

[Ralph Littlefield]

The case doesn’t have headspace

LOL! I think that the language police are here!

But if case base to ogive dimension varies, it will result in headspace variation. Is that worded better?

 

[JFrank]

LOL! I think that the language police are here!

But if case base to ogive dimension varies, it will result in headspace variation. Is that worded better?

Too funny’
Sometimes The press wins the battle and sometimes the case resists sizing.

 

[tmwinds]

The case doesn’t have headspace

fguffey reincarnated.

 

[Ned Ludd]

LOL! I think that the language police are here!

But if case base to ogive dimension varies, it will result in headspace variation. Is that worded better?

The case doesn't have an ogive, either.

 

[Ralph Littlefield]

The case doesn't have an ogive, either.

True! Shoulder ! I'm not doing well at all today!

 

[K22]

Not familiar with the RCBS case mike but is it reliable enough to measure shoulder set back consistently?

I use caliper specific bump gauges, i.e. Widden Gun Works, which reduces measurement variability. I measure with a dial caliper. I obtain fairly consistent results but bump can vary about .001" especially as the brass ages. So for the most part my bump varies between .000 and .002" with the vast majority being about .001". The occasional .000 bump chambers without resistance so I'm ok with that.

As cases age or for different rifles of the same caliber (but have their own dedicated cases) I adjust sizing by using Skim Shims under the lock ring of the FL sizing die. Work quite well and is efficient.

 

[mousegunner]

Well I found some FC once fired .308 brass (out of an M14) tucked away in back. I screwed down the die till it touched the ram, I then put an O ring under the lock ring so I could tighten the lock ring but still move the die. Using the 0.0 as a reference on the RCBS mic the FC brass was .005 longer. I sized the case and it sized to 0.0! Did it 5 more times with same result. Yesterday I sized too much or the case stretched out with just the smallest of adjustment.

Only thing different today was the brass and O ring under the lock ring. I have some primed once fired Win brass and when the range opens I'll shoot it some more and try to resize and see if it gives me the same problem....maybe it was the brass giving me problems yesterday?

The RCBS mic isn't the greatest and I can get good results but I still want some bump gauges for my calipers.

 

[bozo699]

fguffey reincarnated.

PLEASE SAY IT AINT TRUE!.......
Wayne