Help me understand something w/ Fl size & length

[CMV]

If I run a bunch of mixed headstamp .223 cases thru the same Lee FL resize die they should all come out different lengths. But the distance from the base to the shoulder should all be the same. Then if I trim them all with a Possum Hollow trimmer which indexes off the shoulder, I should have all these cases that are the same length. ± a couple thou as neither tool can be "perfect" every time.

But that isn't how they come out. Most are right on, but there's a large % that aren't. I noticed tonight running a batch thru the Dillon Super Swage. Some cases wouldn't feed into it without a lot of encouragement (hit the plate that pushes the shell off the swaging rod). Seemed like they were a decent amount longer overall than everything else.

It might just be stacking tolerances from each tool but I don't think so. PMC, FC, & WCC headstamps only had this problem. PPU, LC, IMI, AP, NNY, unmarked, & probably a couple more all went thru fine. Not every PMC, WCC, or FC, just some, but they were the only ones.

Anyway, it just made me wonder how that happens if they all went thru the same tooling/processes designed to make them uniform. Wasn't a ton - maybe 5 out of a hundred - but if I'm getting 5% cases noticeably longer after FL resize & trim it makes me wonder if that's normal or if I'm doing something wrong in the FL resize operation (nearly impossible to screw up the trim with the PH).

 

[gamestalker]

It's a brass thing. This is why some guys will spend the big bucks for top quality head stamps. Take two pieces of even the same head stamp brass that has been precision sized and trimmed, then weigh it on a beam scale and you'll see the answer to your question. Standard run of the mill brass varies by an incredible degree in thickness, even the same lot number will have quite a large spread. And then once it's been run through the firearm the thicker areas will flow to the easiest or closest spot, sometimes that's the shoulder, sometimes the necks, you got the idea. And even with the good expensive precision brass will have a pretty good weight spread, which is why your serious competition shooters sort their brass by weight.
Even mixed head stamps can produce consistent velocities and groups, if they are weight matched after having been resized and trimmed to precision specification.

 

[Hondo 60]

Are you sure you're resetting the shoulder on 100% of the brass?
If they're mixed headstamp that would certainly create different sizes.

Plus metallurgy can be very different from one headstamp to another.
So some may "spring back" more than others after being sized.

 

[Walkalong]

Exactly.

 

[243winxb]

Press flex/spring may account for some of it. Different amounts of lube on each brass would require different pressure to size. But as said above, its the brass.

 

[918v]

Each brass case is unique. Each will spring back differently. Each will have a different amount of tension on the bullet.

Your observation is normal. You can sort your brass that way if you are looking for ultimate accuracy.

 

[rcmodel]

And brass work hardens every time you fire it and resize it.

Two identical cases, one once fired, and one reloaded 5-6 times will come out different.

Annealing everything once will go far in making them all the same hardness.

rc

 

[NeuseRvrRat]

the dillon super swage supports the case on the case web inside the case. what you're probably seeing is the difference in case web thickness between headstamps and even different lots with the same headstamp. this is why dillon instructs super swage users to sort by headstamp and readjust the locator rod when switching to another headstamp.

 

[rikman]

And brass work hardens every time you fire it and resize it.

Two identical cases, one once fired, and one reloaded 5-6 times will come out different.

Annealing everything once will go far in making them all the same hardness.

rc

RC,

Is this why Lapua charges so much for their brass? I got some awesome accuracy in 308Win in my Savage bolt gun at 600 Yds. Not so much at 200Y with my AR15...I have some Lapua cases with 80Grs Amax's I've yet to try.

Rikman

 

[CMV]

Sorting all the "plinking" brass - even just the crimped stuff by HS sort of takes away from the time savings of the Dillon SS.

But I did see that in the instructions - just didn't understand why it would be an issue if they all went thru the same tooling. I was assuming that the FL die was going to push the shoulder back to the same spot on all of them, regardless of their original dimensions, HS, or other variables. I kind of thought that's what the FL sizing die's purpose was.

It's going to be plinking ammo. As long as it can hit a soda can at 100 yds it will be fine.

I have a couple thousand LC to go thru next, so maybe it will all be close enough that it all feeds well. Not a big deal if a few don't here & there - just wasn't what i was expecting.

 

[NeuseRvrRat]

But I did see that in the instructions - just didn't understand why it would be an issue if they all went thru the same tooling. I was assuming that the FL die was going to push the shoulder back to the same spot on all of them, regardless of their original dimensions, HS, or other variables. I kind of thought that's what the FL sizing die's purpose was.

the web of the case, off of which the super swage indexes, is unaffected by sizing. the super swage does not care where the shoulder is.

 

[MEHavey]

It's a brass (spring) thing. Different manufacturers/firing histories will cause different springback conditions, as does stiffer brass which will "spring" the press just a tad differently as well.

If/when encountered, I usually solve most of the problem by just backing the case down (from full stroke inside the FL die) by an 1/8-1/4" and running it back up again to bump the shoulder twice.

 

[NeuseRvrRat]

Different manufacturers/firing histories will cause different springback conditions, as does stiffer brass which will "spring" the press just a tad differently as well.

this is true, but i do not think it is the reason for the OP's problem.

 

[rcmodel]

I think it is.

Old work hardened brass will not resize as easily as soft new brass.

So, press flex and hard brass spring-back is a very real thing to contend with.

Is this why Lapua charges so much for their brass?

No.
All brass has to be annealed several times during the manufacturing process.
Lapua does it several times, and so does Federal Lake City do it several times.

What I was saying is, every time your fire and resize a case it gets work hardened more.
Annealing it again will soften the neck & shoulder back to normal again.

rc

 

[Walkalong]

I agree with rcmodel as to the OP's problem.

Lapua charges more because it is so much more consistent than other brass. Wall thickness is more consistent, both from case to case as well as being consistent all the way around the case. It is also straight, unlike some brass.

 

[NeuseRvrRat]

Old work hardened brass will not resize as easily as soft new brass.

So, press flex and hard brass spring-back is a very real thing to contend with.

i do not disagree with this. however, i do not see how it's relevant to the operation of the dillon super swage. have you used a dillon super swage before?

 

[MEHavey]

"...do not see how it's relevant to the operation of the dillon super swage."

"...I noticed tonight running a batch [of resized/Possum-trimmed cases] thru the Dillon Super Swage. Some cases wouldn't feed into it without a lot of encouragement (hit the plate that pushes the shell off the swaging rod). Seemed like [the cases] were a decent amount longer overall than everything else...."

The question settled on the position of resized shoulder [case's "headspace" measurement], since that determined the overall case length after the Possum trimmer got through with it. CMV noted that some cases were coming out too long to fit the operation of the Dillon SuperSwager without some "tinkering," and wondered if non-uniform resizing wasn't at the root of the problem.

 

[NeuseRvrRat]

neither case length nor shoulder position have any effect on whether the head of the case hits the black "plate that pushes the shell off the swaging rod" on the dillon super swage. the super swage has a "locator rod" over which the case goes, it centers the case. the end of this rod indexes on the web inside the case. when the locator rod adjustment is held constant, the thickness of that web determines how close the case head is to that black plate with which he is having interference issues. i just do not see how case length or shoulder location could create an interference issue. please explain.

 

[MEHavey]

Seems I'll have to pick up a Swager and find out...

 

[NeuseRvrRat]

i think if you check one out and swage a few primer pockets with it, then you'll understand what i'm saying

 

[rcmodel]

But, the OP's question wasn't about the Super Swage.

He ask how come his resized cases shoulders were not all the same when he trimmed with a Possum Hollow trimmer which indexes off the shoulder.

How the Super Swage got involved, I don't know, but I thought he said the trimmed cases were hard to push on the support rod.

That would be caused by a bur in the case mouth left from trimming.
He needs to chamfer & debur them after trimming but before using the Super Swage.

At least that's what I thought I read in the first post.

rc.

 

[NeuseRvrRat]

from the OP:

I noticed tonight running a batch thru the Dillon Super Swage. Some cases wouldn't feed into it without a lot of encouragement (hit the plate that pushes the shell off the swaging rod). Seemed like they were a decent amount longer overall than everything else.

the super swage got involved when the OP mentioned it. he says that it seems that overall length is his problem, but i informed him that case length has nothing to do with how the case fits in the super swage.

yes, if there was a major burr on the inside of the case mouth left from trimming, then that might cause issues with getting the case on the super swage locator rod, but i think that if that were the case then it would be quite obvious to anyone. not to mention that a case mouth burr has nothing to do with the varying spring-back between various lots of brass.

he does not mention having trouble getting his cases on the super swage locator rod. he says that his problem is with the case head hitting the black plate through which the swage rod goes on the downstroke of the swager. again, this has nothing to do with case length.

once again, i ask, have you ever used a dillon super swage?

 

[MEHavey]

...I noticed tonight running a batch thru the Dillon Super Swage. Some cases wouldn't feed into it without a lot of encouragement (hit the plate that pushes the shell off the swaging rod). Seemed like they were a decent amount longer overall than everything else.

his problem is with the case head hitting the black plate through which the swage rod goes on the downstroke of the swager. again, this has nothing to do with case length.

See http://www.youtube.com/watch?v=LaZHeSUqQbk

Reading what the OP describes and looking at the video, ... it sure looks like a case length problem.
(Although I can't imagine clearances being that tight)

 

[NeuseRvrRat]

i honestly can't tell if you're serious or if i'm being trolled out of my mind

 

[CMV]

Ok - I just went back through a bunch to find one that hangs up feeding. I measured it & it was exactly 1.750" - the same as another HS that fed just fine. The mouths are not hitting the flared part of the rod that holds the case which is what would happen if they actually were too long. Was a bad assumption on my part that they weren't fitting due to being too long.

The ones that "don't fit" actually do - I just have to wiggle the plate that pushes the shell off to get them to seat. That indicates that the web thickness (or some other condition causing the rod to bottom out "higher") and not the OAL is where the variation lies.