June 10, 2014, 10:14 PM | #1 |
Senior Member
Join Date: May 1, 2009
Location: Burnet, TX
Posts: 727
|
Case headspace issue
So I got a new toy in the hornady headspace comparator gadget. Decided it was time to start FL sizing correctly and bump the shoulder .001" to .002" back. Well I started measuring what I have been doing and came across something that doesn't make sense. I was zeroing the calipers on a fired case so my resized cases should be (-) negative.
My .308 was getting bumped back -.004": okay, fine a little adjustment and it'll be set. My .223 was getting bumped back -.008": for an AR I'd like it to be -.003" so I need to tweak it a bit. My .280 was measuring consistently +.004": how the heck are my sized cases larger than my fired cases? I measured several cases I had previously sized against ones I shot today. I have no idea how it's possible to get the shoulder moved forward but clearly I have a problem. Any ideas?
__________________
Veteran OEF (2002) and OIF1 (2003) - US Army Member of the Burnet Gun Fighters, Inc. and of course the NRA Oregon State University alum -- Go Beavs! |
June 11, 2014, 02:35 AM | #2 |
Senior Member
Join Date: September 28, 2013
Posts: 3,827
|
Case headspace issue
The die resizes the brass body as well. When the brass is squeezed to a smaller diameter, the shoulder can go forward if there is room for it to do so. It is possible to have a longer brass after resizing. Just screw down the die 1/8 of a turn. You should see -0.005".
Another possibility is that the expander ball pulls the shoulder back up. To rule this out, try taking out the expander ball, size and remeasure. -TL Last edited by tangolima; June 11, 2014 at 02:45 AM. |
June 11, 2014, 05:05 AM | #3 |
Senior Member
Join Date: February 15, 2009
Posts: 8,927
|
Use these labels on your dies to easily adjust them.
http://s860.photobucket.com/user/jep...ent-1.jpg.html Print them on sticky back label paper and they'll work great. |
June 11, 2014, 09:47 AM | #4 | ||
Senior Member
Join Date: July 18, 2008
Posts: 7,249
|
Quote:
Quote:
Meaning the case does not get stuffed into the die, this leaves a gap between the bottom of the die and top of the shell holder, me? When the case whips the press I measure the gap between the bottom of the die and top of the shell holder with a feeler gage, some use light. Reloading has not been fair to me, the amount of resistance to sizing from case to case is not the same, some cases require more effort because they have more resistance to sizing. The misinformation started when someone made up the cute saying, fire form your cases, neck size them for the next 5 firings then start over by full length sizing, then there is that part where the case is not full grown until it has been fired 'X' number of times.. And that I find impossible, how can a reloader start over with a case that has been fired 6 times? And not of the reloaders making this stuff has a feeler gage and never check to see if the press won or the case won. There are methods and techniques, I want to know if my press , die and shell holder has the ability to size the case back to minimum length, I want to know if it is necessary to return the case to minimum length by full length sizing. Reloaders throw around the numbers of bump .001", "I bump my shoulders .002" etc." without explaining how. They size the case, remove it from the press then measure, after measuring they size the case again, remove the case and measure again and repeat this process until they obtain the magic number? You can install the cut outs, then what? I do not assume the press, die and shell holder won, I verify, to verify measure the gap between the shell holder and die. Logic ask, why use the cut outs if the reloader is going to verify the gap, forget the cut out when converting degrees to thousands or degree of rotation? Go straight to the verifying tool, the feeler gage when making adjustments. Then there is flex and deflection, the case has the ability to resist sizing, some more than other, that could lead to more flex and deflection. Reloaders go through the motion of sizing by assuming, not me, I have presses that flex, I have presses that came with a warranty/guarantee not to flex and or deviate, I am the only reloader that purchases the non flexing presses that has the ability to determiner fact and fiction, truth from nonsense. In an effort to sort through problems a reloader was having I found he had screwed the die down 2 turns after contact with the shell holder. The gap between the bottom of the die and shell holder was .014", the press was an A2 RCBS. F. Guffey Last edited by F. Guffey; June 11, 2014 at 09:49 AM. Reason: trmobr t from ta |
||
June 11, 2014, 10:11 AM | #5 | |
Moderator Emeritus
Join Date: June 25, 2008
Location: Austin, CO
Posts: 19,578
|
Quote:
Once the case shoulder contacts the brass shoulder, it will "bump" the case shoulder shorter. Mr Guffey's preceding 8 paragraphs of drivel notwithstanding, the process has been explained many times. If you're getting +0.004, that tells you that the die needs to be at least 0.006 lower in the press. You can use feeler gauges to check the current gap and then use 0.006 less to set the new gap, or you can simply proceed with trial and error. 0.006 is roughly 6/70ths of a turn or just less than 1/10th or roughly 1/3rd of 1/4th. Contrary to the opinion of some, estimates and rough adjustments are fine. We're not going to the moon here, it's only ammunition.
__________________
Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley |
|
June 11, 2014, 10:28 AM | #6 |
Senior Member
Join Date: May 1, 2009
Location: Burnet, TX
Posts: 727
|
Awesome Brian and tango, that's the information I was looking for. I now understand the mechanics of it. Sorry if I brought up a topic that is beat to death.
Guffey, I am using a Lee turret press. And feeler gauges are not perfect either. Whatever method you choose, be it measuring die rotation or using a feeler gauge both have error and both have operator error. If they both accomplish the same task if a person is better one way than the other I'd say its a case of the ends justify the means. I will try this sans feeler gauge just because I don't like the term "feeler gauge" -- kinda creeps me out.
__________________
Veteran OEF (2002) and OIF1 (2003) - US Army Member of the Burnet Gun Fighters, Inc. and of course the NRA Oregon State University alum -- Go Beavs! |
June 11, 2014, 10:51 AM | #7 |
Moderator Emeritus
Join Date: June 25, 2008
Location: Austin, CO
Posts: 19,578
|
Oh, one thing the feeler gauges are good for is to take up the slack between the case and the shellholder. If you can't get the sizing you need for whatever reason (it would mostly mean you had a very short chamber or a defective die) you can slide a gauge under the case in the shellholder so it it held tight as high as it can sit. There's usually at least 0.015 available there.
__________________
Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley |
June 11, 2014, 11:24 AM | #8 | |
Senior Member
Join Date: January 5, 2009
Location: Just off Route 66
Posts: 5,067
|
Quote:
Post #2 explained it all. That's why you trim your cases AFTER you full length resize and not BEFORE. Jim
__________________
Si vis pacem, para bellum Last edited by Jim243; June 11, 2014 at 11:44 AM. |
|
June 11, 2014, 02:17 PM | #9 | |
Senior Member
Join Date: May 27, 2007
Posts: 5,261
|
Quote:
__________________
If I'm not shooting, I'm reloading. |
|
June 11, 2014, 02:41 PM | #10 | ||
Senior Member
Join Date: July 18, 2008
Posts: 7,249
|
Quote:
Quote:
Then there are other terms that must be dribble like: Standard, transfer and verify, all three terms apply to the feeler gage. F. Guffey |
||
June 11, 2014, 02:54 PM | #11 | |
Senior Member
Join Date: July 18, 2008
Posts: 7,249
|
Quote:
Maybe not this time. I assure you the case will get longer from the mouth of the case to the case head if the the sizer plug is removed. I will assure you the case will get shorter if the sizing plug is not removed. F. Guffey |
|
June 11, 2014, 05:12 PM | #12 |
Senior Member
Join Date: September 28, 2013
Posts: 3,827
|
From shoulder, not the mouth, to the head.
-TL |
June 11, 2014, 07:10 PM | #13 | |
Senior Member
Join Date: January 5, 2009
Location: Just off Route 66
Posts: 5,067
|
Quote:
Via or with. Jim
__________________
Si vis pacem, para bellum |
|
June 11, 2014, 07:18 PM | #14 |
Senior Member
Join Date: April 14, 2013
Location: Milwaukee, Wisconsin
Posts: 2,693
|
Sans means Without.
|
June 11, 2014, 09:44 PM | #15 | ||
Senior Member
Join Date: July 18, 2008
Posts: 7,249
|
Quote:
So I was misquoted with the "There's usually at least". Sans: Vie, or with or without? Quote:
Even then, a fired case gets longer when sized, if a reloader could figure a way to measure the case before the ram was lowered they could prove it. When the sizer plug is pulled through the neck of the case the case gets shorter. F. Guffey Last edited by F. Guffey; June 11, 2014 at 09:57 PM. |
||
June 13, 2014, 12:22 PM | #16 |
Senior Member
Join Date: April 10, 2008
Location: Alaska
Posts: 7,014
|
Now the Butt Grinder thing has me creeped out!
|
June 13, 2014, 06:58 PM | #17 |
Senior Member
Join Date: September 15, 2007
Posts: 1,707
|
To OP, perhaps the issue is your press? I too have the Classic Cast Turret press, and I have found that I get very uncertain results on bottleneck cases when trying to arrive at uniform shoulder setback. Perhaps a change to a Rock Chucker or the like will assist you some.
Too PMA make a lock ring that will help you in setting your dies for proper shoulder bump. Die Lock Ring PMA Lastly, unless you anneal your cases each time, the best I have achieved in terms of consistent shoulder bump is +/- .001 from my target setting. There are inconsistencies in brass springback otherwise as the brass work hardens. Lube film thickness will also affect your results. I have found the Lee toothpaste lube when applied with an atomizer, and diluted about 6 to 1 with ISO alcohol gives the most consistent lube film, without sticking cases. Also, since some gets in the case neck, the expander ball doesn't drag the neck out of concentricity on many cases. Some do get out of line. HTH. |
June 15, 2014, 01:16 PM | #18 | ||
Senior Member
Join Date: July 18, 2008
Posts: 7,249
|
Quote:
Quote:
I did not spend a lot of time looking at 'it'. I can not master bumping, I have bump presses, I can adjust a press to bump if It was designed to bump but when the shoulder portion of the die contacts the shoulder of the case the body of the case supports the case body and the neck sizing portion of the die has already finished sizing the neck. The best I can od is controll the length of the case from the shoulder to the case head, again, I can not do that without case body support. F. Guffey Last edited by F. Guffey; June 15, 2014 at 01:22 PM. |
||
|
|