I'm not gonna ask which one is better, I'm sure that I will find accolades for both.  What I would like to know is if anyone knows what the difference is between them.

I resized a bunch of LC13 brass with my Redding die.  No problems or issues.  My fireformed brass out of my Rem 700 comes in at around 1.625 +/-.  I set up my Redding die to bump it back to 1.615 +/-.  And the LC13 brass that I was working on had shoulders around the 1.635 mark.  I actually had it set up for all of my brass that I had previously resized to that dimension, not specially for the LC13.  It resized beautifully pushing back the shoulder smoothly.

I was trying out neck sizing with an RCBS neck die on some brass that was fireformed out of my rifle.  I screwed up big time and mixed up my dies.  I was stingy with the lube thinking I was using the neck die and stuck a case in my Redding die.  I removed the case, replaced the bent stem and tried to use it again today.  The brass is coming out with striations along the body, I guess I need to run some lapping compound in the body to smooth out any scratches I may have made removing the stuck case.

So I tried FL sizing using my brand new, unused Forster full length die.  What a difference between the two.

I set up the sizing die as I have in the past in accordance with it's instructions........ handle down (RCBS Rock Crusher), turn die in till it makes contact with shellholder and adjust from that point to get the results I am looking for.

As I get close, but not at, my target bump to 1.615, I observed that the stroke in the ram hits the die before I can get to my number.  Is this "normal" because I didn't have this issue with the Redding die?  Should the shellholder be a Forster shellholder as opposed to the Hornady I always use?  I can see where the case is being bumped down, there is a very obvious line on the shoulder, but it's not able to make it's way down to the body.

Am I "doing it wrong"?

Fired is 1.625"  and you want to size to 1.615"    The .010" difference is to much shoulder set back, if your numbers are correct??  The deck height of shell holders are standard .125"   give or take .001"  

You should only need to resize the brass back .001 - .002 for bolt action ammo.

For semi-autos you'll need to resize back .003-.004 for reliable feeding.

Back from what?  The fired brass (LC12) I'm working with is fireformed to 1.635.  I'm trying to bring the shoulder back <1.620 so that it takes the shape of my chamber.  With the Redding die this was no problem, with the Forster I get close to 1.625 and my shoulder looks like it has a step smushed into it.

1.635-.002=1.633, maybe you are over doing it?

Back from whatever your fired case measures.  If you are sizing your fired brass (which measures 1.635) back to 1.620, then you are oversizing and overworking it.

Need a Photo of >      If it looks like this, its from the seating die, to much crimp????

Your seating die is turn down too far. The crimping function is smashing the case mouth downwards collapsing the case shoulder.

My apologies, I wasn't clear.  The LC12 is range brass, never fired through my rifle.  Heck, it probably went through an MG for all I know.

When I said it was smushed I mean there is an entirely new shoulder being made....... I think that saying the die is too far into the press is an accurate statement.  (I'll try and put up a photo).  The denting is happening before the shoulder gets bumped back anywhere near the 1.620 "standard" that I thought all dies were cut to.

Is there any chance whatsoever that the two dies are "cut" to two different dimensions?  Manufacturer's difference?  Competition vs standard FL die?


Thanks for the replies!!

Yes, you are doing it wrong.

Your brass should be sized about 0.002" shorter than your fired cases.  Sizing to 1.615" is too short (0.010" shorter than your fired cases).  

SAAMI minimum is 1.627".  That your cases come out of the chamber at 1.625" means they are not fully fire formed OR you have a short chamber (below SAAMI spec).  I'd suggest 1.622" or longer, if your chamber is actually longer.

You can do it the old fashioned way, too.  Size, test fit, resize,... until chambers, then measure length and do the others to that size.  


How did you manage to damage your die?  Do you know how to remove a stuck case with a stack of washers and a bolt?  

So...... I have brass that is 1.635 fireformed.  Where it came from, what it was shot through, I have no idea.  I have brass that was fireformed in my bolt action Rem 700 that measures 1.625.  You are all saying that I should resize the brass to 1.625 - .001 to .002.  I am on board with that.  What I fear you are missing because I am not making it clear is that using my Redding Competition die this was not a problem.  I was able to resize 200+ rounds of LC13 to exactly those numbers.  I reread my OP and where I got 1.615 is still a mystery to me.  After switching to a Forster die, I can't even get close.  I'm not talking about +/- .002, I'm saying that I need to bump the brass back .010" to get it to 1.625 from 1.635.  I used the ole Sharpie method of marking the neck and shoulder to see how far the case was going up into the die.  Using that method, I determined that even when the neck was fully inserted into the die, there was no contact with the shoulder (the shoulder remained at the original 1.635 as measured with my Hornady headspace attachment to my digital caliper).  In order to make contact with the shoulder to bump it back, let's forget about the number for a moment, the shoulder begins to deform, using my imagination it's as if the die is cut to some other "shape".  I understand how the shoulder deforms during firing when there is excessive room to do so, and how a die then "reshapes" the shoulder to SAMMI specifications.

I have tried to google the difference between "competition dies" and standard FL dies and am still unclear.  I'm definitely not saying or even thinking that this is the cause of my headache, I don't even know if there is a difference so how could I.

As for how I removed the stuck case...... I pulled the stem out as far as I could (the ball was being held by the neck I assume), drilled then tapped the case, inserted a 1/4-20 and bent the crap out of all of my made in china washers.  Got online with Amazon Prime and they sent me a RCBS kit which I used to extract the brass...... that sumbitch was a mother to get out.

I replaced the stem and tried using the die but it got scratched somehow and is now leaving marks on the brass.  I tried sourcing a replacement die but all I could find were sets.  I tried running some lapping compound on a mop but it's still leaving marks.  Thinking about asking if Redding can fix it.