THE ACCURATERELOADING.COM FORUMS


Moderators: Mark
Go
New
Find
Notify
Tools
Reply
  
Partial Full Length Sizing
 Login/Join
 
one of us
posted
This is a question for Hot Core and others that use this method.

OK, this is what I did, I backed the FL die out to about a nickels thickness from the shell holder, Started resizing and turning the die in 1/16 to 1/8 turn each time. After several 1/8 turns I found the bolt becoming more difficult to close. I then started to turn the die in at very very small increments. I never did find a spot that the bolt would not close, but, I did find a point that closing the bolt was very very hard. I made a reference mark on the die and press. At this point I turned the die in such a small amount I could barely notice the change in the reference mark. The bold closed with ease and just a slight "crush fit".

Then, when I locked everything down and started to size up some brass I noticed that this "sweet spot" cams over and is only about an 1/8 of a turn from the RCBS recommended die setting ( turn down to touch shell holder and add 1/4 turn). Did I do something wrong or is this about where I should have found my "sweet spot"?
Thanks
 
Posts: 1205 | Location: Minnesota | Registered: 07 February 2004Reply With Quote
one of us
posted Hide Post
quote:
Originally posted by steve4102:

Then, when I locked everything down and started to size up some brass I noticed that this "sweet spot" cams over and is only about an 1/8 of a turn from the RCBS recommended die setting ( turn down to touch shell holder and add 1/4 turn). Did I do something wrong or is this about where I should have found my "sweet spot"?
Thanks


When you use this method, you try to attain the die adjustment, which will just set back your shoulder enough to let the cartridge chamber freely. Normally, this is envisioned to be a reduction in head-shoulder dimensions of about .001-.002" from fired to sized shape. Exactly where you reach the desired die adjustment totally depends on the dimensions of the die vs. the dimensions of the chamber vs. the brass you use (brass springback is a factor here).

So to answer your question, the fact that you are close to the factory recommended die adjustment, does not indicate anything other than this is the point, at which you reach the case size reduction you have been looking for.

The fact that you ask the question, probably means you are worried, that getting this close to the factory recommended setting will have pushed back your shoulder excessively. This is the weakness of the method you have used to achieve "partial full length" sizing. You simply can't know exactly how much your shoulder has been set back, and it is hard to be sure it was not another case dimenension that needed reduction before your case chambered freely. You can try to assess this by measuring case diameter at shoulder and in front of the case head (fired vs. sized) while you adjust your die. If the case diameters are reduced before you reach your "sweet spot", you are probably ok.

To be 100% sure, you need a headspace gauge and actually measure the difference in head-shoulder dimension on a fired vs. a sized case. Stoney Point makes a nifty gauge for about 20-30$. The gauge is not perfect, but it is very versatile, can be used with multiple calibers, and takes 99% of the guesswork out of the equation.

- mike


*********************
The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
 
Posts: 6653 | Location: Switzerland | Registered: 11 March 2002Reply With Quote
one of us
posted Hide Post
Hey Steve, You did great! Congratulations on your P-FLR.

Due to manufacturing "Tolerances" in the Press, Shell Holder and Dies, plus the initial dimensions of your cases, it is difficult to describe the process so you get it done correctly. Your post said it as well as I've seen it and much shorter than I can post it. Please share your method with others as you see them ask and it will keep me from wasting lots of Bandwidth.

Interesting observation about how close you are to the recommended RCBS Die Setting Method. Speaks well for your "chamber".

After you shoot the P-FLRed cases, you might need to Fine Tune the Die Setting just a bit, or you might not have to move it at all. When you resize one of those P-FLRed cases that has been fired, after screwing the FL Die into the press until the Lock Ring touches, back it out 1/16-1/8 turn and see if the "Tight Fit" is still there. If it is, screw it back down to the Lock Ring and P-FLR that case once more and try it in the chamber again. If it has the "slight crush feel", go on about your P-FLRing.

I just reverify the Setting because it occasionally may need a bit of tweeking. And you do not want an entire Lot Loaded and then find they are a bit too tight(voice of experience Big Grin).

Congratulations. You did it correctly and didn't need to waste money on any extra devices that tell you what you already know.
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
One of Us
Picture of woods
posted Hide Post
quote:
Originally posted by Hot Core:

Congratulations. You did it correctly and didn't need to waste money on any extra devices that tell you what you already know.



Just couldn't resist getting in that dig to all of us Stoney Point users, could you! jump

Steve4102, like HC says everything sounds like it happens just like it was supposed to. If you had a Stoney Point Head and Shoulders Gauge you could have watched it happen with exact measurements on your caliper. And, if you have a rifle like a couple of mine that the bolt closes tight anyway, you would be able to PFLR without having to feel by closing the bolt on the case exactly when that point of slight crush fit happens.


____________________________________
There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice.
- Mark Twain |

Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others.

___________________________________
 
Posts: 2750 | Location: Houston, Tx | Registered: 17 January 2005Reply With Quote
one of us
posted Hide Post
just reverify the Setting because it occasionally may need a bit of tweeking. And you do not want an entire Lot Loaded and then find they are a bit too tight(voice of experience ). Fireformed brass will vary,fireformed brass may measure differently due to alloy and temper variations in the brass,work-hardening,which results re-sizing and firing,will have an effect,type and amount of lube aplied to the case can have an effect on the resized dimensions.High primer will "shorten" headspace.Using the head and shoulders cartridge headspace gauge makes it easier.HARD BRASS WILL PROBABLY SPRINGBACK MORE THAN THE OTHERS. Stoney point users Cool
 
Posts: 439 | Location: Quebec Canada | Registered: 27 August 2001Reply With Quote
one of us
posted Hide Post
quote:
Just couldn't resist getting in that dig to all of us Stoney Point users, could you!
To quote Flip Wilson(surely everyone remembers him), "The Devil made me do it!" Big Grin
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
one of us
posted Hide Post
quote:
Originally posted by Hot Core:
quote:
Just couldn't resist getting in that dig to all of us Stoney Point users, could you!
To quote Flip Wilson(surely everyone remembers him), "The Devil made me do it!" Big Grin
_______________________________________________________________________________________________________________ Hotcore the way you adjust the sizer "without the gauge" is the best way to go Cool thumb I think one should buy one,cost not that much,but dont forget to buy the anvil base kit(ab-1)otherwise it will be hard to use,I am a little confused about "springback of the case,I know that thing exists but one must take under consideration others variables. You have a good sens of humour ,what will be reloading without it...
 
Posts: 439 | Location: Quebec Canada | Registered: 27 August 2001Reply With Quote
one of us
posted Hide Post
quote:
Originally posted by rejpelly:
...I am a little confused about "springback of the case,I know that thing exists but one must take under consideration others variables. You have a good sens of humour ,what will be reloading without it...
I much prefer laughing than arguing.

There are various kinds of "springback":
1. When a Case is fired it Expands to fill the Chamber and even stretches the Chamber slightly. As the Pressure is going back down after the shot, the Brass begins Contracting from it's Stretched condition (springback).
2. When a Case is Full Length Resized, the Case wall, shoulder and neck are all squeezed until they are slightly below the SAAMI Minimum. Then as the Ram is lowered, they each "expand" slightly and are just a bit larger(springback).
3. As the Expander is pulled through the neck, it increases the neck diameter and after it has passed through, the neck contracts slightly to a bit smaller diameter(springback).

This ability the Brass has to Expand and Contract is what makes it so useful as Case material. Over time the repeated Expansion and Contraction will "Work Harden" the Case Necks and they need to be Annealed to return the Elastic ability. Otherwise, they will eventually exhibit "Splits" in the Necks.

The Case wall and shoulder do not experience the same amount of Expansion and Contraction that the Neck sees, so they do not work harden as quickly. An over-size chamber or an under-size Die has the potential to overwork the Case wall and shoulder, but I've not heard of that happening in many years and have never experienced it myself.

You can have Cases that "split" or develop "Pin Holes" in the Walls, but that is generally from the cases being exposed to Ammonia causing embrittlement or the Cases having the wrong "Temper" from the factory.

Best of luck to you.
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
one of us
posted Hide Post
I would make my determination by what I intended to use the rifle for...For big game hunting and especially dangerous game hunting I want a slop fit of a full length resized case and will forfiet the accuracy which is very minimal, For varmint hunting I want a very light crush fit. for target about the same...

My main varmint rifle has "O" tolerance, and hand dies, requires outside neck trim to even chamber......I could actually use it without resizing the case I suspect.

At any rate I determine my reloading practices by what I intend to use the rifle for...


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 42309 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
  Powered by Social Strata  
 


Copyright December 1997-2023 Accuratereloading.com


Visit our on-line store for AR Memorabilia