Full Length Sizing FNG Question

Choupique

WKR
Joined
Oct 2, 2022
Messages
581
I am reloading .338 win mag norma brass. I have been neck sizing up to this point. After 3 firings, it was tight to chamber it so I decided I'd figure out this whole shoulder bump thing. I made myself a little comparator out of a 10mm socket, measured one that was tight, put a FL die in and screwed it down till it was tight on the case, sized it, tried it, screwed it in a little more, size it, tried it. I ended up with the die all the way against the shell holder, basically how the instructions recommend setting it before it chambered like new. According to my crude comparator I'm getting 0.002-0.004" of shoulder bump this way. Sounds like I just magically got the right combination of stuff for it to work out that way?

I had read and been told that sizing brass this way dramatically overworks it and results in exceptionally short case life and risk of case head separation with belted magnums. According to my comparator and rifle, it's what it takes to get it chambering like I want it to. Am I about to start blowing case heads this way? How do you even properly check if you're in danger of splitting a case head?
 
Joined
Mar 31, 2019
Messages
3,745
Location
Weiser, ID
Shoulder bump is the way, you're doing it correctly and having the die screwed all the way down isn't an issue unless you get excessive sizing.
 
Joined
Jan 26, 2017
Messages
3,139
Location
PA
by going 3 firings before touching the shoulder, you gave your cases plenty of time to fully expand and headspace off the shoulder vice the belt. you shouldn't have any issues.
 

MtnW

WKR
Joined
Jul 15, 2020
Messages
358
I always full length size my hunting loads. Having case/cartridge problems on a serious hunt is the last thing I want to deal with .
 
Joined
Oct 2, 2021
Messages
331
Location
Central Virginia
I always full length size all my loads. I own a few 3 die sets that came with neck sizing dies, but I have never even set them up. Reliability is way more important to me that marginal case life.
 
OP
Choupique

Choupique

WKR
Joined
Oct 2, 2022
Messages
581
Thank yall. Part of my concern I guess is I hear people say they full length size, which to me means die against shell holder, but then they say stuff like "I full length size to bump the shoulder X thousanths." I don't understand what that means. Seems that prevailing internet opinion is that follow the instructions in a full length die kit is going to blow my rifle up in my face which didn't make much sense to me.

I'll carry on as I am going. I've just been lead to believe that die against shellholder + belted mag = case head separation.

For now, I'm not planning to load them more than 4 times before tossing them anyway until I get more comfort and experience with what I'm doing. Ive got enough brass for a while. I've been through about 200 rounds and still don't know what powder I want to use. I was liking RL17 with 250gr grand slams until I found out I was getting 150fps over book velocity at 1 grain under book max.
 
Joined
Dec 30, 2014
Messages
9,701
I’m not sure I understand your comparator setup but I’d not expect a belted mag FL sizing due to be all the way against a shell holder to get 2-4 thou bump.
 

Koda_

WKR
Joined
Dec 24, 2023
Messages
305
Location
PNW
I hear people say they full length size, which to me means die against shell holder, but then they say stuff like "I full length size to bump the shoulder X thousanths." I don't understand what that means.
All it means is they are using a FL sizing die, but they arent sizing the full lenght of the case because its not needed if you just move the shoulder .002-.003" so it chambers freely. The idea of "shoulder bumping" is to back off the dia (from against the shell holder) just enough so the shoulder moves.

It can be a little tricky to learn, there are a couple things you can do to make it easier.
1) for me I could not get .002/.003" consistency until I started annealing the brass before sizing. You dont need an expensive annealer, just a propane torch method works fine.
2) Get yourself a Forster Accu-ring, they are cheap and have marks on the ring in .001" increments. Replace your sizing dies lock ring with this, set up against the shell holder and snug the Accu-ring only finger tight, then mark the die with a sharpie. Then back it off .010" and lock it down. Start there and size a case and measure its shoulder with your comparator. Adjust the die either way until your shoulder only moves .002 from the fireformed dimension.

 
OP
Choupique

Choupique

WKR
Joined
Oct 2, 2022
Messages
581
not sure I understand your comparator setup

It's a 10mm socket stuck over the end of the case and a regular caliper which best I can tell, that's about what the hornady tool is. All I was trying to do was figure out how far down I had to screw the die in until I started pushing the shoulder back, and ended up bottomed out before I got any movement on my gizmo and the case would chamber easily again.


not expect a belted mag FL sizing due to be all the way against a shell holder to get 2-4 thou bum

Me either. It thought it'd be more like 0.050 or something. I figured I must be doing something wrong. Maybe my measurement just sucks.
 

seand

WKR
Joined
Sep 22, 2012
Messages
328
Location
Tigard, Oregon
Thank yall. Part of my concern I guess is I hear people say they full length size, which to me means die against shell holder, but then they say stuff like "I full length size to bump the shoulder X thousanths." I don't understand what that means. Seems that prevailing internet opinion is that follow the instructions in a full length die kit is going to blow my rifle up in my face which didn't make much sense to me.

I'll carry on as I am going. I've just been lead to believe that die against shellholder + belted mag = case head separation.

For now, I'm not planning to load them more than 4 times before tossing them anyway until I get more comfort and experience with what I'm doing. Ive got enough brass for a while. I've been through about 200 rounds and still don't know what powder I want to use. I was liking RL17 with 250gr grand slams until I found out I was getting 150fps over book velocity at 1 grain under book max.

Your socket comparator seems suspect to me, but easy to check your work….

Add scotch tape to the bottom of the case head until you feel resistance on bolt close. 1 layer of scotch tape is ~ 0.002”. Easy enough to verify your headspace measurement.

FL size vs Partial FL sizing is silly. It’s all FL sizing if you are bumping the shoulder. You want to make sure you have room to chamber brass in a field rifle, but aren’t excessively setting back the shoulder. In a hunting rifle 0.003-0.005 is good. If I’m in that range I don’t adjust anymore.
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
1,693
I was in your boat a couple years ago. I started by neck sizing but just like you, I only got a couple firings which makes sense.

When someone says they're FL sizing, it just means they're using a FL sizing die. It doesn't have anything to do with how much they're sizing. I switched to this method because it is just easier and more dtraightforward. My favorite setup is the RCBS matchmaster set with a FL bushing die and the seating die with the window. I see no reason to have anything else for every rifle cartridge I reload.

Do this next time, screw it to the shell holder and loosen it one full turn. Size the brass. I bet you'll find that it actually grows. Screw it in 1/4 turn increments and measure the shoulder. At some point in there it will likely be the same size as when you started. Bump it another 1/4 turn or so and you'll be awful close to your 2thou bump. Lock your collar and be happy. I have some dies I have to screw in past where they touch to get some cam over on the die to bump the shoulder. Hitting the shell holder is arbitrary.

Go ahead and buy the comparator kit. While you're at it, get the one for bullets too. This will make your life much easier. On top of that, get the OAL tool and your set to find the lands and start tweaking seating depth with some accuracy. Measure a handful of bullets and you'll see the length of them are different. What's typically more consistent is measuring the ogive. In this case, that's where the bullet measures .338.

Good luck and
 
OP
Choupique

Choupique

WKR
Joined
Oct 2, 2022
Messages
581
screw it to the shell holder and loosen it one full turn. Size the brass. I bet you'll find that it actually grows. Screw it in 1/4 turn increments and measure the shoulder. At some point in there it will likely be the same size as when you started. Bump it another 1/4 turn or so and you'll be awful close to your 2thou bump. Lock your collar and be happy.

This is what I did. I just found it was all the way down before it started chambering like I want it to.


Go ahead and buy the comparator kit. While you're at it, get the one for bullets too. This will make your life much easier. On top of that, get the OAL tool and your set to find the lands and start tweaking seating depth with some accuracy

I'm really trying to avoid buying every gizmo and doodad there is for this game. I'm not sure I'm that committed yet. I'd rather just run the die all the way down and toss the brass after 3 shots for now. Seems like everything I think about doing there's a pile of gizmos for sale to deal with it. Seems like a very slippery slope.

I found the lands via neck sizing a case, cutting a slit in the neck, seating a bullet in it wayyyyy too long, chambering it and measuring that OAL, and taking the average of 5. They usually come in within a couple thou each time and always dramatically longer than the magazine for every bullet I've tried so far.

I'm still in the don't blow myself up phase of this. Groups look good though!
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
1,693
This is what I did. I just found it was all the way down before it started chambering like I want it to.




I'm really trying to avoid buying every gizmo and doodad there is for this game. I'm not sure I'm that committed yet. I'd rather just run the die all the way down and toss the brass after 3 shots for now. Seems like everything I think about doing there's a pile of gizmos for sale to deal with it. Seems like a very slippery slope.

I found the lands via neck sizing a case, cutting a slit in the neck, seating a bullet in it wayyyyy too long, chambering it and measuring that OAL, and taking the average of 5. They usually come in within a couple thou each time and always dramatically longer than the magazine for every bullet I've tried so far.

I'm still in the don't blow myself up phase of this. Groups look good though!
I completely understand. The tools I recommend, I use every single time that I sit down to reload. They are really invaluable. However, there are plenty of things that I've bought along the way that I don't use anymore so I get it. If you're already setup with what you need to reload, I doubt you're not going to do it but my personality is to deep dive into everything that I do. Good luck man!
 
Joined
Mar 28, 2020
Messages
929
Forget all the shit you read on the internet about comparators, shoulder bump etc.

To set up a FLS die lube a tight case, including inside the neck
Put the die in the press and screw it down till it hits the shellholder, then back it off a whole turn
Size the case and try it in the rifle, most likely it will be tight
Lube a DIFFERENT tight case, screw die in 1/16 of a turn and try again
Repeat this process until you are happy with the feel of the sized case in your rifle, set the lock ring and you are done
 

JGRaider

WKR
Joined
Jul 3, 2019
Messages
1,836
Location
West Texas
I'm very much a simplest solution person. I just want accurate reliable ammo, preferably less than $5 a pop.
If you're into simple, use a Lee collet neck sizing die and rifle specific brass. No lube needed, and you won't have to bump shoulders or do what Castle Rock suggested above every 4-5 loadings on that brass, at least that's how it works out for me.
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
1,693
If you're into simple, use a Lee collet neck sizing die and rifle specific brass. No lube needed, and you won't have to bump shoulders or do what Castle Rock suggested above every 4-5 loadings on that brass, at least that's how it works out for me.
What are you shooting that you don't have to bump the shoulder back after a few firings? I think the instructions for the die even mention it.
 
Joined
Mar 28, 2020
Messages
929
What are you shooting that you don't have to bump the shoulder back after a few firings? I think the instructions for the die even mention it.
Every rifle I own except for my 6.5 Creed which wants FLS after about 5 due to the shitty Hornady brass I am using
 
Joined
Mar 28, 2020
Messages
929
And the first thing you should do when you buy dies is chuck the directions away, they really are catering to the dumbest customer that they expect to encounter
 

Latest posts

Featured Video

Stats

Threads
349,544
Messages
3,681,984
Members
79,967
Latest member
M700
Top