Case stretch during full length resize

[JD Jones]

I am currently starting the process of resizing my first ever batch of 1x brass (newb question)
I have a Redding S full length that I have removed the decaping pin and shaft. Cases are deprimed in previous step. I have inserted my bushing, placed the little black piece on top then capped the die. The bushing has just a little wiggle/rattle. The die is on a co ax. Die was set up by actuating the ram fully, screwing the die to shell holder contact, then backing off ~.25 turn.

I took initial measurements on the fired brass of 1.607 case length and .529 at the case web

After running through die. I get 1.609 case length and case web was unchanged.

I expected case length to go the other way….Am I fubar somewhere or is this normal?

Brass is ADG cartridge is 6.5 PRC.

Note: different lot but ADG brass brand new: 1.608 case length and .528 case web

 

[Reelamin]

I'm in to learn something. I can't give advice as I really don't worry about case length unless I am having a problem. I have always trimmed after sizing. The last one I ran to failure was some 6.5 Suck It Moor Starline..... stopped and put them in the big pile at 12 shots with a 140 and 42.0 of Super. Not one thing done other than clean it size it shoot it....gun is still shooting .5" or less at 100.

 

[can1010]

as long as the sized once fired brass fits in your gun and bolt opens and closes freely just load and shoot.

none of the measurements mean anything until it is fired and measured in your gun. the .529 web measurement is about right for fired brass. once you have fired brass from your gun and is fully expanded to your chamber then worry about shoulder bump

 

[cjuve]

Watch this:



If your case is longer after running through the die you need to screw your die down.

 

[PddPdd]

After sizing with your current die setting, how does the brass fit your chamber? Any bolt closing resistance?

If yes, I agree with screwing the die down slightly to get .001-.002" back so that it will chamber smoothly after sizing.

Note: If you attempt to resize the same piece of brass twice to reduce your headspace the die setting could be different then if you did it in one step. You'll want to set your dies to do it in one step and deal with those that didn't shorten enough by annealing them and then sizing again. Hope that makes sense.

BTW, the bushing die size lettering should be up when the die is installed in your press.

 

[JD Jones]

After sizing with your current die setting, how does the brass fit your chamber? Any bolt closing resistance? Yes bolt will not close
Note: If you attempt to resize the same piece of brass twice to reduce your headspace the die setting could be different then if you did it in one step. You'll want to set your dies to do it in one step and deal with those that didn't shorten enough by annealing them and then sizing again. Hope that makes sense.

BTW, the bushing die size lettering should be up when the die is installed in your press.

Lettering like so?

 

[Dmagna]

Screw the die down more, see if that helps

 

[Murtfree]

I think what you are experiencing is completely normal and is just basic brass flow. Now that the case has been fired and stretched to fit your chamber and you force it back to specs, the "extra size/stretch" has to go some where and it usually shows up as brass flow into the neck because it is the only place it can go. I find my cases do this fairly often especially when you are dealing with the first or second firing; I always anneal and trim after the first two firings. After that any excess brass relative to your chamber is mostly gone and the stretch is usually negligible. Cases with sharper shoulder angle like the Ackley's tend to show less brass flow

 

[Welderboy11972]

Are you measuring over all case length or are you measuring shoulder to base?

If you measuring over all length. They will get longer after you run them through the sizing die. You may need to trim them.

If you are measuring shoulder to base. Then you do need to screw your die in. As your die sizes the body of the brass it will push your shoulders up, until the shoulder contact that part of your die. Then it will push the shoulder back to where you set it.

 

[David Urasky]

The "cheap" or should I say inexpensive dies are none adjustable as far as shoulder bump. They are meant to have the bottom of the die touching the shell holder. Infact camming I believe is propper. The higher end dies are cut slightly short so that bump can be adjusted to what ever is needed. They are not set up with the shell holder in contact with the die. Thus if you want the cases longer, just screw the die up. If you want it shorted for a short chamber, not a problem. But that means you need to pay attention to cartridge length when setting up the die.

 

[skipglo]

DMAGNA said it right. Screw the die down a 1/4 turn on sizer not up so the press Cams over. Screw the seater Up a 1/4.

 

[30BR]

Case length not as important as base to mid-shoulder. Buy a Whidden die, and use the included tool to check that distance. Its normal for 1st firings to sometimes contract OAL as the case expands radially.

 

[QuietTexan]

first ever batch of 1x brass

For starters:

• Your Redding Type S die is great, you don't need to buy a different die, the Redding die will work correctly for you (at least for right now). This isn't a die problem in your situation.
• There is nothing wrong with a 0.002" length increase on the first resizing.
• There is nothing wrong with the web not sizing down on the first resizing.
• You don't necessarily need to screw it down tighter, instead focus on correctly setting up the die.
• I would recommend a headspace comparator to assist setting up the die correctly.
• Your brass likely hasn't grown enough yet to worry about bumping shoulders yet. (Murtfree )
  • This is why you're seeing a length increase from the body being sized, but the shoulders aren't being moved by the die.
  • Or you've set it up so tight already you're bumping the shoulders back too far and causing growth, and screwing the die down will just make your excessive sizing problem worse.
  • The best (IMO) solution that will be accurate and repeatable starts with measuring and getting hard numbers to work with.

Where I would start it this:

1. Check the fit of the brass how it is now, as-fired and before sizing, in the chamber. Does the bolt close without resistance? Do you have to jam it home? (exactly what PddPdd said , but if you have any brass you haven't sized yet try them also)
2. Measure the shoulder with a headspace comparator.
3. Set up your die correctly, even if that means it doesn't move the shoulder on the first resizing - watch Greg's video below
4. Cases will increase in length even with the PRC shoulder. Don't bother trimming until the cases stabilize. If you load a round and chamber check it, make sure it doesn't have a shiny ring at the end of the case neck that would indicate it being too long. Odds are they aren't after one firing. (You can also run a digital borescope down from the muzzle to check a fired case in the chamber to see how much length you have to spare).
5. PRC die problem - don't worry about it yet.

How to set up a die correctly: (instructions included with dies are not correct for 90+% of sizing situations IMO)


Functional:
Amazon product ASIN B000PD5VN8
Fancy:

Modular Headspace Comparator – Kit

This kit comes complete with 4 inserts of your choice, one long body, one short body and the stand. Please make sure you select 4 headspace or bullet inserts. Save $55.00 compared to purchasing individually! *** Solid Bullet Inserts are for bullets similar to Cutting Edge Solids Lathe turned...

shortactioncustoms.com

Teslong borescopes (there are a bunch of options, I use the flexible wifi model):
Amazon product ASIN B096Z65FT7

 

[PddPdd]

View attachment 328240Lettering like so?

Sorry I didn't get back to you sooner. I had computer issues over the weekend.

My Redding bushings have the lettering at one end of the cylinder shape so that piece of advice does not apply for bushing orientation.

The video from Primal Rights (above) covers the details extensively so hopefully all your questions have been answered. If not, please inquire further.