How much should your die be sizing

[RyeGuy]

What clearance do you want with a sized case after FL sizing? Are you shooting for Minimal clearance say 1/2 thou to 1 thou, or 5-7 thou? I’m having stiff bolt with 3x fired brass using Whidden die and wondering if I just deal with it or size with the RCBS? I feel like the RCBS is sizing too much?? Any advice from some experienced guys would be appreciated! I’ll attach pic of what my 2 dies are sizing to and see if you think the RCBS is sizing too much. Or should I keep using Whidden, or go custom? Or keep buying new brass every 2-3 firings? It’s a hunting gun so I don’t fire too many rounds a year after I get a load…
thanks

 

[ELR LVR]

338 Norma Specs call out for .585" Base Dia.
Looks like the RCBS is on
the Whidden is off
cartridge drawing Pg. 1

https://sierrabullets.com/content/load-data/rifle/338/338-norma-magnum.pdf

---
I would show everything here to whidden and request a replacement FL die that sizes your base to .585"
---
FWIW, every RCBS die I have is perfect
---
It is very likely you are over pressurizing your cases if your .200" line is expanding
at all, in any way, IE: dont let it
(Edit: sorry I meant the area just above the extractor groove should not be expanding,
the so called .200" line is kind of arbitrary more refering to the area just above the web
Also called "The Pressure Ring"
--- reference the Dia. of a Fired Factory round to get a gauge for what the Dia. should be there)

 

[TheOtherZilla]

I go for 2-3 thou bump on the shoulder.

 

[Straightshooter1]

What clearance do you want with a sized case after FL sizing? Are you shooting for Minimal clearance say 1/2 thou to 1 thou, or 5-7 thou? I’m having stiff bolt with 3x fired brass using Whidden die and wondering if I just deal with it or size with the RCBS? I feel like the RCBS is sizing too much?? Any advice from some experienced guys would be appreciated! I’ll attach pic of what my 2 dies are sizing to and see if you think the RCBS is sizing too much. Or should I keep using Whidden, or go custom? Or keep buying new brass every 2-3 firings? It’s a hunting gun so I don’t fire too many rounds a year after I get a load…
thanks

At the .200 line I wouldn't want .003 movement as that's A LOT of movement down there when sizing. I think .001 to .0015 should be plenty and will give you better case life. For that shoulder junction, .003" of sizing (like to .575) is good. I don't feel like .001 is enough and certainly .008" is too much. I wouldn't use the RCBS die given the numbers you've shown (way too much movement going on when sizing). So, the Whidden die looks just a little too tight at the shoulder junction and you might want to get hold of them to see if they'll ream it out a little for you at a nominal price.

That expansion from those new case number to what you show after firing is really a huge expansion and certainly will shorten case life, just due to that first firing. You should be able to get more that 3 firings out of your cases. . . .

. . .especially if you do some annealing.

Don't forget shoulder bump on your hunting gun should be something like .002 to .003 of bump. IMHO

 

[RyeGuy]

I go for 2-3 thou bump on the shoulder.

That’s bumping shoulder 3 thou… I’m more worried about the wall size, not shoulder.

 

[RyeGuy]

338 Norma Specs call out for .585" Base Dia.
Looks like the RCBS is on
the Whidden is off
cartridge drawing Pg. 1

https://sierrabullets.com/content/load-data/rifle/338/338-norma-magnum.pdf

---
I would show everything here to whidden and request a replacement FL die that sizes your base to .585"
---
FWIW, every RCBS die I have is perfect
---
It is very likely you are over pressurizing your cases if your .200" line is expanding
at all, in any way, IE: dont let it

I have 3 pieces of brass at Whidden now, waiting for reply. Asked the builder and he said use RCBS, claimed that much resize ain’t bad. (I feel like it’s?)
So when you say I’m over pressuring the .200 line.. If the chamber isn’t supporting that area, are you saying the brass won’t grow as long as I’m not over pressure? So my chamber is 7thou bigger then new brass, won’t new brass blow out that 7 thou on first fire? Or will that brass hold strong unless over pressure? No other pressure signs.. Didn’t have any issues till 3rd firing of this brass. And not sure it really an issue, just a lil heavy bolt, which is what made me dig into all this and figure it all out. Thanks

 

[Steve Donlon]

I see with some of the brass I use that it is very hard to keep all the brass bumped to exactly the same spec. to within .001"or even .002" with some outliers. I guess that's why some anneal every time. Mine get bumped from 1-3 at the most without annealing every time.

 

[L.Sherm]

.003-.004 isn't to much to size at the .200 line it all depends on brass sometimes like with Lapua or ADG look at the AW2 reamers for the PRC's to avoid clickers
Tighter isn't always better.
I dont anneal my Lapua and ADG for my LR hunting rifles but I keep them segregated to times fired and get consistent bump.

 

[ELR LVR]

There are 2 places to measure from
Keep in mind the so called .200" Line, is an open term where it is not at the same height above the rim for every cartridge, this area is just above the Web shown below in the picture.
So cut open a case and see where this area is, it may .300" on the 338 Norma
If so, it is likely not a big deal if your cases are expanding there.
To know how much is acceptable, fire a "Factory Loaded Round" and measure the case dia. there.
This number will be your gauge for that inspection point
The area the 2 arrows are pointing at in the pic is where the brass thins down internally,
This area just above the case Web - is where you would measure from a
fired "Factory Round"
Shoot a few factory loaded rounds and measure there
----
Second area to measure for overpressure is just above the extractor groove
the area just above the extractor groove should not change dimension upon firing
The rim, should not change dimension upon firing
The primer pocket also, should not change dimension upon firing.
----
The rest of the brass above it yes, expands and fireforms to the chamber
The Base, Web, Area just above extractor groove should not be expanding
if it expands more than .0005" (Thats 5/10ths of 1 Thou) means overpressure.
----
One of the main issues with this is, also if the base expands, the primer pocket has to follow
It will also eventually no longer be able to hold a primer
----
Use a paper clip with a small "L" bent into one end as a feeler tool
Reach down into the case with it and run it along the inside up and down in the web/.200 line area to feel for a definite "Catch/ edge/ thin spot etc" as shown in this drawing
Toss any brass you feel this thin spot, as it is about to rupture and separate
---
In short, no your brass should not be expanding as far down as the area just above the extractor groove.
Since the Web area is engineered to contain recommended pressures, it should not expand if staying within those pressures
Also keep in mind, you are "Work hardening" that area if it is being expanded and resized
That area will become the weakest link, hence why it will separate there.
So by not expanding that area at the base, and having to resize it down, you also prolong your brass life for many more reloadings.

 

[L.Sherm]

Repeatedly stretching and sizing down at the .200 Line will cause premature case head seperation.

Doesn't on my Lapua and ADG brass, I have 10 firings on some excessive bump will on any brass.
Like I said look at the AW2 reamers you have to do the same thing with Lapua in a 20VT

 

[6.5 forever]

I only shoot long range steel now days. Stiff bolt lift doesn't bother me. I only push the shoulder
.001-.0015. If I was competing in timed events or hunting I would double the push.

 

[243winxb]

3 firings. It takes this many till the brass actually forms to the chamber.

Didn’t have any issues till 3rd firing of this brass.

"Hard" bolt lift would require a reduction of the powder charge.

Over working the necks, by sizing down to much, shortenes case life. Here, a bushing die can extend case life to 20+ loadings.(Unless pressure is running near 76,000 PSI)

Hunting rifle- If brass fits chamber, after sizing, good to go.
It aint Benchrest.

 

[L.Sherm]

It aint Benchrest

Doesn't matter if its BR, Hunting or Target if the Die to chamber fit isn't right it sucks.

 

[RyeGuy]

There are 2 places to measure from
Keep in mind the so called .200" Line, is an open term where it is not at the same height above the rim for every cartridge, this area is just above the Web shown below in the picture.
So cut open a case and see where this area is, it may .300" on the 338 Norma
If so, it is likely not a big deal if your cases are expanding there.
To know how much is acceptable, fire a "Factory Loaded Round" and measure the case dia. there.
This number will be your gauge for that inspection point
The area the 2 arrows are pointing at in the pic is where the brass thins down internally,
This area just above the case Web - is where you would measure from a
fired "Factory Round"
Shoot a few factory loaded rounds and measure there
----
Second area to measure for overpressure is just above the extractor groove
the area just above the extractor groove should not change dimension upon firing
The rim, should not change dimension upon firing
The primer pocket also, should not change dimension upon firing.
----
The rest of the brass above it yes, expands and fireforms to the chamber
The Base, Web, Area just above extractor groove should not be expanding
if it expands more than .0005" (Thats 5/10ths of 1 Thou) means overpressure.
----
One of the main issues with this is, also if the base expands, the primer pocket has to follow
It will also eventually no longer be able to hold a primer
----
Use a paper clip with a small "L" bent into one end as a feeler tool
Reach down into the case with it and run it along the inside up and down in the web/.200 line area to feel for a definite "Catch/ edge/ thin spot etc" as shown in this drawing
Toss any brass you feel this thin spot, as it is about to rupture and separate
---
In short, no your brass should not be expanding as far down as the area just above the extractor groove.
Since the Web area is engineered to contain recommended pressures, it should not expand if staying within those pressures
Also keep in mind, you are "Work hardening" that area if it is being expanded and resized
That area will become the weakest link, hence why it will separate there.
So by not expanding that area at the base, and having to resize it down, you also prolong your brass life for many more reloadings.


View attachment 1711478

Great info! Thanks for that explanation.

 

[RyeGuy]

3 firings. It takes this many till the brass actually forms to the chamber.

"Hard" bolt lift would require a reduction of the powder charge.

Over working the necks, by sizing down to much, shortenes case life. Here, a bushing die can extend case life to 20+ loadings.(Unless pressure is running near 76,000 PSI)

Hunting rifle- If brass fits chamber, after sizing, good to go.
It aint Benchrest.

I wouldn’t say it’s “hard” bolt Lift at all. it was just a little stiff, which was the first time experiencing that with that load.. After looking at Sammi specs I think my one die is too big. I’ll see what they say after analyzing my fired brass. Thanks all for the info

 

[ELR LVR]

Great info! Thanks for that explanation.

No problem
Factory cartridges such as magnums are often loaded to Max Safe Pressures which is why its good to be able to use those as a comparison

 

[hoz53]

I see with some of the brass I use that it is very hard to keep all the brass bumped to exactly the same spec. to within .001"or even .002" with some outliers. I guess that's why some anneal every time. Mine get bumped from 1-3 at the most without annealing every time.

my 6br lapua brass i use for accuracy loads will springback to differant base to shoulder dimensions after a few loads. i now anneal every firing and it has helped with that and ES has also improved.

 

[L.Sherm]

I wouldn’t say it’s “hard” bolt Lift at all. it was just a little stiff, which was the first time experiencing that with that load.. After looking at Sammi specs I think my one die is too big. I’ll see what they say after analyzing my fired brass. Thanks all for the info

I wouldnt go off saami shooting Lapua brass it needs more sizing at the .200

 

[cdgaydos]

I found that my consistency in bump got much better with the Redding Competition shell holders… they allowed me to set my dies to the perfect amount of cam over while adjusting bump with the shell holders…

Full disclosure, I anneal every firing with an AMP…

Just for what it’s worth.
Chris

 

[Shooter13]

Asked the builder and he said use RCBS, claimed that much resize ain’t bad. (I feel like it’s?)

Not being a wise guy, if you don't trust the builder of the gun why would you let him build it? RCBS will not size it too much. You're good with that, you do not want bolt click or hard bolt lift. I can promise you sizing correctly will not affect accuracy!