Shoulder Bump Help

Cosmic338

Ammo will become Currency
Full Member
Minuteman
Dec 11, 2020
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United States
I’m new to reloading and I’m soon going to start reloading some .338 Lapua and I read about neck sizing and bumping the shoulders back. I know the neck sizing is done on a single die, but is there a die specifically for shoulder bump? Or is it bumped with a FL sizing die? I’m just lost on this.
 
That’s the video I watched about an hour or 2 ago. I did take in a lot of information and he explained everything well but when he brought up shoulder bump and FL sizing, The only thing I could put together is he’s using a FL size die to bump shoulders back? But in that case wouldn’t that affect the fire formed brass, making it not fire formed anymore?
 
That’s the video I watched about an hour or 2 ago. I did take in a lot of information and he explained everything well but when he brought up shoulder bump and FL sizing, The only thing I could put together is he’s using a FL size die to bump shoulders back? But in that case wouldn’t that affect the fire formed brass, making it not fire formed anymore?
You can size a bit to ensure function and uniform case treatment without taking it all the way back to minimum specs.
 
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It depends on what works for you but I use competition Redding dies for my .338. Order of work:

1) deprime
2) wet tumble
3) anneal
4) body only die to bump shoulder .001 to .002
5) neck bushing die only (since I use a mandrel latter to set neck tension I use a bushing that gets me to .0025 to .003 and then expand to .002). If you buy the S type FL die you can combine steps 4 and 5 with one pull of the press but since I bought the competition set to start I’ve never switched
6) trim / chamfer
7) dry tumble to remove lube
8) expand necks to .002 tension with dry lube
9) charge and seat bullets
 
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Watching the Panhandle Precision series' have really helped me understand this and other topics. It's well-worth the time investment. On this topic, I'd simplify it by saying that bumping the shoulder back a couple of thousandths with each firing ensures a cartridge will always seat comfortably in the chamber. It's as simple as that.
 
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That’s the video I watched about an hour or 2 ago. I did take in a lot of information and he explained everything well but when he brought up shoulder bump and FL sizing, The only thing I could put together is he’s using a FL size die to bump shoulders back? But in that case wouldn’t that affect the fire formed brass, making it not fire formed anymore?

Yes. Once FL sized, even with minimal shoulder bump, the case is no longer fire formed. It is smaller than its fire formed dimensions by about .005”, but still larger than its unfired size.

Don’t get hung up on this fire forming stuff. It doesn’t make a difference except when you’re crunching powder with compressed loads.
 
It depends on what works for you but I use competition Redding dies for my .338. Order of work:

1) deprime
2) wet tumble
3) anneal
4) body only die to bump shoulder .001 to .002
5) neck bushing die only (since I use a mandrel latter to set neck tension I use a bushing that gets me to .0025 to .003 and then expand to .002). If you buy the S type FL die you can combine steps 4 and 5 with one pull of the press but since I bought the competition set to start I’ve never switched
6) trim / chamfer
7) dry tumble to remove lube
8) expand necks to .002 tension with dry lube
9) charge and seat bullets
So what I’m getting here is that the body die is the die used to bump the shoulder? People aren’t buying some specific custom die that only bumps shoulders?
 
“So what I’m getting here is that the body die is the die used to bump the shoulder?”

Yes, the body die sizes the body and bumps the shoulder back.

However, Forester, as will others, hone custom dies if that’s the route you decide to go.
 
So what I’m getting here is that the body die is the die used to bump the shoulder? People aren’t buying some specific custom die that only bumps shoulders?

Just for clarity-
A full length sizing die will size the neck, bump the shoulder, and size the body.
A neck die will size the neck.
A body die will bump the shoulder and size the body.

So, in order to have a fully resized case, you need to either run a FL die (1 step), or a body die and a neck die (2 steps).
It may be cheaper to practice these concepts on your 223 loading first, instead of trying to learn by launching 5$ bills...
 
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Yes standard FL dies will move shoulder how far depends on how far you screw them in. Some people prefer to have a die that just moves shoulder.
 
Just for clarity-
A full length sizing die will size the neck, bump the shoulder, and size the body.
A neck die will size the neck.
A body die will bump the shoulder and size the body.

So, in order to have a fully resized case, you need to either run a FL die (1 step), or a body die and a neck die (2 steps).
It may be cheaper to practice these concepts on your 223 loading first, instead of trying to learn by launching 5$ bills...
This does clear things up thanks. And yeah I’ll start with something else less expensive lol