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Necksize vs FL size 338LM
- Thread starter Norwegian musher
- Start date
I neck sized then bumped shoulder as needed .002” with Redding body die. Many FL size every time bumping shoulder .002”.
Generally I use Lee collet die/Redding body die for my ammo. I used a Redding bushing die for my 338 when I had it
If I decide it’s time to FL size on brass I’m only neck sizing on then I FL size the entire batch together.
Generally I use Lee collet die/Redding body die for my ammo. I used a Redding bushing die for my 338 when I had it
If I decide it’s time to FL size on brass I’m only neck sizing on then I FL size the entire batch together.
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First off, the principles are going to be the same whether you are shooting a 6mm or a 338. Also, you'll get varying answers.
My take:
- If you only neck size, you run the risk of eventually having extraction issues. Why? Because each shot the brass will continue to expand to the chamber (which also expands and contracts during the shot) and spring back a bit. It will eventually get to a point where the brass doesn't spring back enough and you get heavy bolt lift - or even stuck or broken components on extraction.
- This means that you need to FL size at some point regardless. OK, so why not just neck size for a few firings, then FL size? Well, if you're like me, you're not firing all your cases every time out, so if you only FL size every so many firings, then you will be in a scenario at some point where you are firing some cases that have just been FL sized and some that haven't been for 1, 2, 3, etc. firings. Are these cases consistent in size? No. That means they are also not consistent in volume, which means they are not consistent in pressure created by the same amount of powder.
- This basic premise is why I anneal every firing - I want the cases to all be as similar as possible.
Erik Cortina has a rant about this on YouTube.
How have you survived this long without being made to swallow your own teeth?
What does it matter if it's Erik, or any other championship winning F-Class or Benchrest record holder. They all say the same thing.
I look at Erik like I look at every other successful individual in a given profession:
He is a source of information that I should take note of. It doesn't mean you need to take everything at face value, but If you ignore or write off someone who is as successful as he is in his specialty, then you are a fool.
I alternate between neck sizing, FL sizing and annealing, but I’m just a hack.
I started loading for my TRG in January of 2006, so I have a little bit of experience.
Chris
I started loading for my TRG in January of 2006, so I have a little bit of experience.
Chris
I did it at one time. Never again. It didn't make any difference how the loads shot and plus after several firings the bolt was a PITA to cycle. Have gone back to full length sizing with neck bushings.
Can you give an example of anyone at the top of F class or BR disciplines who advocates for neck sizing?
I was using the 338 Lapua Mag Competition Bushing Neck 3 Die Set but change a few years back and went with small base FL neck sizing die and then open the neck back with a mandrel die. With the Redding body die it was getting hard to chamber after 2 firings but now I have 6 firing on my current Norma brass with no problems.
I shoot an AI-PSR 30in 1-9.3 Bartlein barrel.
I shoot an AI-PSR 30in 1-9.3 Bartlein barrel.
I've neck sized my .308 cases a lot and not had any issues, though I also anneal and bump the shoulders every time. My current batch of Federal brass that I've done this with has 9 firings and chambering still working just fine.
I haven't done this on the Lapua brass I have, as I've alternated where I've done this neck sizing a few times then FL sized and not detected any differences between the two methods (neck and shoulder dimensions are the same).
The issue, like so many have pointed out, is when the case reaches a point where there's extraction problems. That'll certainly happen when shoulders are not bumped back when neck sizing and have been there and done that. But on that Federal brass that's been fired 9 times with that neck sizing and shoulder bumping, I haven't seen a problem yet and watching to see if a problem with the web or body eventually leads to an extraction problem. So far, I'm inclined to think not, because the web and body is work hardening as I go and thus the springback either remains or become more prominent where it shouldn't contribute to any extraction problems. It probably helps too that my firearm is not taken into really dirty or dusty environments. I guess I'll see how it goes as I go into the 10th firing or more on that Federal brass.
I haven't done this on the Lapua brass I have, as I've alternated where I've done this neck sizing a few times then FL sized and not detected any differences between the two methods (neck and shoulder dimensions are the same).
The issue, like so many have pointed out, is when the case reaches a point where there's extraction problems. That'll certainly happen when shoulders are not bumped back when neck sizing and have been there and done that. But on that Federal brass that's been fired 9 times with that neck sizing and shoulder bumping, I haven't seen a problem yet and watching to see if a problem with the web or body eventually leads to an extraction problem. So far, I'm inclined to think not, because the web and body is work hardening as I go and thus the springback either remains or become more prominent where it shouldn't contribute to any extraction problems. It probably helps too that my firearm is not taken into really dirty or dusty environments. I guess I'll see how it goes as I go into the 10th firing or more on that Federal brass.
If you are moving the shoulders then you arent neck sizing only and thus dont have neck sizing only problems.
What die are you using that moves the shoulders without any body support to keep it from buckling?True. But it's not FL sizing either.
I think what Spife is getting at is that the die is almost certainly providing support to at least some of the body below the shoulder. If the case was simply floating in space it could bow out and create a donut beneath the shoulder while it was being pushed down, even if only a couple thousandths.
Certainly not moving as much brass as a full-length resizing die, but at least some of the case body below the shoulder is probably also being resized with that die.
If my assumption is incorrect, I'm down to learn something new, but I just can't fathom how you wouldn't blow out the body while putting downward pressure on the case to move the shoulder if at least some of the body wasn't supported (and probably getting resized if only a small amount)...similar to pressing straight down on an empty soda can and having the sides crumple as it gets shorter.
I tried neck sizing only for a .308 for a bit and didn't see the benefit of better groups, so I just FL resize all my brass each time now.
Certainly not moving as much brass as a full-length resizing die, but at least some of the case body below the shoulder is probably also being resized with that die.
If my assumption is incorrect, I'm down to learn something new, but I just can't fathom how you wouldn't blow out the body while putting downward pressure on the case to move the shoulder if at least some of the body wasn't supported (and probably getting resized if only a small amount)...similar to pressing straight down on an empty soda can and having the sides crumple as it gets shorter.
I tried neck sizing only for a .308 for a bit and didn't see the benefit of better groups, so I just FL resize all my brass each time now.
When bumping the shoulder (.0015 - .002") after neck sizing with a collet die, I get no measurable change in the OD at the shoulder-body junction. A donut may be forming on the ID of that junction, but I can't tell and if so, it doesn't interfere with anything. FYI: I don't use the bushings of the above die to size the neck, only use the die to bump the shoulder; getting better concentricity than using the bushings.
What I found interesting was that after neck sizing the head space measurement on the case increased ~ .001" along with the case's OAL of ~.0015 - .002", indicating flow of the neck material in both directions. How much flow there is into the shoulder will depend on how soft the shoulder is from the annealing process. And that's logical to me when thinking about how the collet die works to size the neck.
While I also see no real advantage in terms of what I get on paper, I'm sure this neck sizing method (along with the annealing) results is very little work hardening of the case body as FL sizing does, thereby increasing the life of the brass.
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Agree completely with this. Had a month where I was having "pressure signs" with my 338LM Kreiger barrel. They were false pressure signs from neck sizing.
Neck sizing is one of those things that was mindlessly adopted from the benchrest community (me included) to areas where it has no place and even does harm.
I now use the Redding S dies to FL size the case, bump the shoulder, and the right bushing for the desired neck tension. I note that my $2000 custom WTC 50 BMG die does exactly the same thing, albeit with a different design.
Interesting that you don't get a measurable difference in the OD below the shoulder using the die. I wonder if it's moving so little it springs back.
Or you realize yourself and him are trying to meet very different end goals, as far ammo accuracy requirements.
Given that I anneal after every firing, I wouldn't think there's much springback, even at that area of the case. But now as I think about this more, I wonder if there's some compression going on that reduces the diameter at the neck-shoulder junction when bumping the shoulder as I do. I suspect that like the body-shoulder junction, there'll not be enough change to detect with a caliper.
Fools look up to assholes like him . The rest of us are comfortable in our own skin . I guess if i sucked at this sport and liked a sarcastic dick maybe I would be fool enough to worship him .
How fast you run into problems neck sizing, is going to be directly proportional to how much pressure your ammo is making.
Haney has a participant sash, from the Miss California bitter ole bitty beauty pageant. Some one named N. Pelosi won.
Haney has a participant sash, from the Miss California bitter ole bitty beauty pageant. Some one named N. Pelosi won.
I found with my 338 LM that I had to full length resize or I would get difficult bolt lift and extraction. I am even considering a small base sizing die to further reduce this issue. I also recommend annealing after each firing as it extends the life of my Lapua brass. I too am a fan of using a mandrel for the neck.
Very true, but that's not my point. The point is that I take information in from a variety of sources and make an educated decision based on my own experience and what those sources espouse.
I'll never fly acrobatic jets, but that doesn't mean I won't listen to what Chuck Yeager has to say and possibly incorporate some of it into my discipline.
EDIT: I should say that I'll never regularly fly acrobatic jets. I've flown acrobatic prop aircraft, and if I somehow think that I'd rather fly an hour in a jet fighter/trainer than, say, get a new rifle with a ZCO and all the goodies, then this could happen at some point.
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