Question Full size or Neck size brass for Accuracy ?

[LHSmith]

Not buying into Reddings sales pitch. The whole intent of the JLC and PMA micro adjuster is the ability to easily and incrementally (as small as 0.0005") push the shoulder back as dictated by measuring the sized case. The cases sized by using the Redding Comp. S/H's offer 0.002" adjustment and some of those cases will spring back (after sizing) to less bump than may be optimum. ...in other words - how can you assume these cases have an equal bump? They never will without the ability to finely adjust ram height -to-s/h interface.What am I missing about these magical S/H's?

 

[Patch700]

Not buying into Reddings sales pitch. The whole intent of the JLC and PMA micro adjuster is the ability to easily and incrementally (as small as 0.0005") push the shoulder back as dictated by measuring the sized case. The cases sized by using the Redding Comp. S/H's offer 0.002" adjustment and some of those cases will spring back (after sizing) to less bump than may be optimum. ...in other words - how can you assume these cases have an equal bump? They never will without the ability to finely adjust ram height -to-s/h interface.What am I missing about these magical S/H's?

This pretty much sums it up from my experience.... My redding comp shell holders have pretty much been relegated to fancy paper weights on the loading bench with regards to fine incremental sizing.

Pats adjustable lockring is my go to with regards to keeping things "easily" uniformed.

I have had some instances where the comp shell holders of reddings where "ok" but certainly not a set it and forget it type of solution.

 

[BoydAllen]

I do most of my shooting with a 6PPC and for that brass I have not had a problem with bump variation, but a friend has had that issue, and setting up to toggle slightly at the top of the stroke has helped him get better uniformity for his varmint loading with .223 and .22-250. He as done it both ways, first by making a brass shim, and also with the Redding shell holders. The difference between what he is doing and what I do is that he runs large batches of cases, so resetting dies for increases in work hardening is less of an issue than it is for me with small batches, used over and over. For that, I find the PMA adjuster very handy. I also like it for the control it gives me when coming up to my desired bump. It makes it much easier to not overshoot my mark.

 

[Brians356]

I have had some instances where the comp shell holders of reddings where "ok" but certainly not a set it and forget it type of solution.

No adjustable lock ring can possibly be more repeatable than the competition shell holders, in the same press.

The only aspect of the Reddings I will concede is that they come in .002" increments, so if you feel you need to fine tune the shoulder dead on to .001" or be relegated to shooting larger groups, then I suppose the point has merit.

But with the comp shell holders, spring-back will be the same for every case (assuming the same lot of cases, all maintained the same), so whatever case measurement you get from a particular .002 increment shell holder will repeat for every case. No other system described here can be more repeatable.

 

[LHSmith]

I have found running a 6 PPC or 30 BR full throttle + , tweaking bump between cases is a given.

 

[LHSmith]

But with the comp shell holders, spring-back will be the same for every case (assuming the same lot of cases, all maintained the same), so whatever case measurement you get from a particular .002 increment shell holder will repeat for every case. No other system described here can be more repeatable.

Counters my experience 180.....cases with-in same lot, fired same loads, same number of times have to be constantly measured ....as they WILL vary on how they work harden.

 

[Dusty Stevens]

Anybody that shoots br and runs their cases very hard sees the same as mr smith.

 

[Brians356]

But with the comp shell holders, spring-back will be the same for every case (assuming the same lot of cases, all maintained the same), so whatever case measurement you get from a particular .002 increment shell holder will repeat for every case. No other system described here can be more repeatable.

Counters my experience 180.....cases with-in same lot, fired same loads, same number of times have to be constantly measured ....as they WILL vary on how they work harden.

But, that effect will be the same with some adjustable lock ring method, or any other method. It's not the fault of the comp shell holders that the cases have varying hardness. And no die setup can automatically self-adjust for variable spring-back.

 

[LHSmith]

But, that effect will be the same with some adjustable lock ring method, or any other method. It's not the fault of the comp shell holders that the cases have varying hardness. And no die setup can automatically self-adjust for variable spring-back.

Exactly my point. For my needs 0.002 is too crude of an adjustment. Remember the BR tenet "keep everything EXACTLY the same". Consistent headspace ( casehead to shoulder distance) is paramount.

 

[Brians356]

But, that effect will be the same with some adjustable lock ring method, or any other method. It's not the fault of the comp shell holders that the cases have varying hardness. And no die setup can automatically self-adjust for variable spring-back.

Exactly my point. For my needs 0.002 is too crude of an adjustment. Remember the BR tenet "keep everything EXACTLY the same". Consistent headspace ( casehead to shoulder distance) is paramount.

Since you report seeing varying spring-back within a lot of cases, then you are relegated to sizing a case, measuring, adjusting the die as required, measuring again, etc. Then backing out the die, then reiterate with the next case etc. Is that your system?

 

[LHSmith]

Since you report seeing varying spring-back within a lot of cases, then you are relegated to sizing a case, measuring, adjusting the die as required, measuring again, etc. Then backing out the die, then reiterate with the next case etc. Is that your system?

During the course of a match, I usually have to make an adjustment via a JLC ratchet die adjuster mounted on a Hood press on a few cases. Prior to that set -up I unscrewed the die from a Redding Boss press and changed die shims as required.

 

[bobinpa]

IMHO unless you anneal, I don't believe springback will be consistent. I have a few sets of comp shell holders and they all vary. Not one set steps down exactly .002 at a time. I have as much as .0035 in a step in 2 sets, so getting exactly .001 or .002 shoulder bump is impossible there.

The shell holders may be repeatable, quick and easy, but they are no way as precise as annealing and adjusting a die to get exactly .001 shoulder bump.

 

[savagedasher]

A dead stop on the dies and or shell holder. I don't think would size all brass to .001 . Larry

 

[Patch700]

A dead stop on the dies and or shell holder. I don't think would size all brass to .001 . Larry

If it did i would be saving a few bucks buying adj. lockrings and merely epoxy shims to the bottom of the die and call er good lol.

 

[AckleymanII]

But with the comp shell holders, spring-back will be the same for every case (assuming the same lot of cases, all maintained the same), so whatever case measurement you get from a particular .002 increment shell holder will repeat for every case. No other system described here can be more repeatable.

Counters my experience 180.....cases with-in same lot, fired same loads, same number of times have to be constantly measured ....as they WILL vary on how they work harden.

I had 4 brands of brass Rockwell tested, there was a 12% variation in hardness, and a 6% variation in hardness of the same brand, all using brand new brass.

Full length sizing dies often push the shoulders back .006 or more to get the Sized web's spring back the way you want.

What we need is a set of straight wall dies that size only the web, graduated sizes, that would be similar to the short RCBS form dies where the top is open, then a shoulder bump die.

Just consider the web dia difference between Win, Lapu, and Norma, it is enough to make your head hurt. Now throw in a minimum spec SAAMI match reamer that would give .005 Chamber clearance for Winchester brass, .001 Chamber clearance for Lapua Brass, and Norma brass would be .002 oversize. Then find out that your Redding body die is the same size as your chamber!

 

[BoydAllen]

What you have described are called ring dies. There is a fellow that has made some recently. In the past, friends who have not quite gotten enough sizing at the head diameter of their cases, because custom chamber reamers were too small there, have used .45 ACP dies like ring dies. One fellow had his problem with a .243 AI chamber. I found an old non carbide RCBS set and all he had to do was remove everything out of the die. Another friend used a Lee carbide die, to size 6mm Remington cases. He had to modify the die on his lathe because Lees are built differently than the old RCBS. In any case, bumping case shoulders .006 is not a viable option. It will cause cases to separate if repeatedly done, in fairly short order. Often when I order chamber reamers, I buy the FL die first, locate some well used work hardened brass, size and measure it, and order the reamer so that I will have the clearances that I want. You do not want to do this with new brass because as it is used and work hardens it will come out of the die larger than when it was new. For this, you want brass that has bee fired and Fl size a lot.

 

[amlevin]

But, that effect will be the same with some adjustable lock ring method, or any other method. It's not the fault of the comp shell holders that the cases have varying hardness. And no die setup can automatically self-adjust for variable spring-back.

Exactly my point. For my needs 0.002 is too crude of an adjustment. Remember the BR tenet "keep everything EXACTLY the same". Consistent headspace ( casehead to shoulder distance) is paramount.

Since you report seeing varying spring-back within a lot of cases, then you are relegated to sizing a case, measuring, adjusting the die as required, measuring again, etc. Then backing out the die, then reiterate with the next case etc. Is that your system?

Not to mention that all those cases with varying "spring back" will also have that as a "variable".


If one absolutely, positively, has to have, everything equal, then anneal after every firing. That should even out "spring back".

 

[Barlow]

To the op. I went thru the neck sizing is the only way to gain accuracy mantra years ago, and found it to be not anymore accurate (in my rifles) than full length sizing properly done with minimum shoulder set back. I did try the Lee collet die and shoulder set back die routine on my 12 FTR 308 and it worked well, but not any better than full length sizing. I full length all cases and save myself a lot of aggravation. Barlow