When I ful length resize with my RCBS die I get 0.242 out side neck measurement and when I neck size with my Lee collet neck die I get 0.244 out side neck measurement on Lake City 5.56 cases. Which is the right size ? If the RCBS sizing die is set too low would it make the neck diameter smaller ? I am reloading these cases for my Tikka T3x Varmint in 223 cal.
case sizing ?
- Thread starter rebs
- Start date
Alot of issues here. 1rst off, no your die height will not affect your neck size. It will however affect your head space. Do you have some once fired brass from your rifle? You need this to measure your cartridge base to shoulder height. You'll need a few tools for this. A caliper and headspace gage. Your looking to get .002" less than your chamber. This is important as your accurcy and brass life.
2nd, as too yourneck diameter seat a bullet and take another measurement, seems most think that best accuracy is around .002" neck tension. thats the easy way to get that measurement.
3rd, do you have an experienced reloader you know who could mentor you for awhile to get you on the right path. And also read a good reloading manual. Don't just skim through, read it!
Good luck, be safe and keep asking questions!
2nd, as too yourneck diameter seat a bullet and take another measurement, seems most think that best accuracy is around .002" neck tension. thats the easy way to get that measurement.
3rd, do you have an experienced reloader you know who could mentor you for awhile to get you on the right path. And also read a good reloading manual. Don't just skim through, read it!
Good luck, be safe and keep asking questions!
jepp2
Gold $$ Contributor
Try a couple of things.
1'st measure the case neck OD's after you have seated bullets in both. This will tell you how much case neck tension you have from each.
2'nd, measure the collet die mandrel diameter, and figure you will at best be at least 0.001" larger due to spring back.
3'rd, remove the decapping expander rod from your RCBS die and size a case. Measure the OD of the case neck. This is how much your die is undersizing your case neck before the expander passes through it.
You can always either buy an undersize Lee collet mandrel if you want more case neck tension. You will know how much your case neck is being expanded in the RCBS die, and you can make it less (smaller) if you reduce the diameter of the expander.
Different brands of brass will yield different results. And as the case neck work hardens, the LCD will have more springback.
I have been reloading for years but am totally new to neck sizing. I do all the case prep but the neck sizing is all new to me. When I measured the necks it surprised me to see a difference. I am using a Lee collet neck sizer and bought a new mandrel that is .002 smaller than the one that came with it and it surprised me in the RCBS still sizing the neck smaller.
Dusty Stevens
Shiner
now is a real good time to lay it down and NOT get experienced in neck sizing. It's not a bad habit to you just yet so you're way ahead of a lot of people on here with case sizing issues that heard the bad rumor from the 50's that neck sizing has even one advantage. Get a good FL bushing die and start from scratch. you'll cut your learning curve by a long time.
Hmmm??? Just curious, if you don't mind . . .
Have you compared the difference between FL and NS with factory barrels?
I have in just the one factory barrel I have and found the neck sizing consistently gave me the better results. So, this is only anecdotal evidence for neck sizing. But. . . it seems to me that FL sizing would be the better way to go as you say for high end or custom barrels along with a custom die.
Dusty Stevens
Shiner
barrels matter none, its all about case fit. and if I was throwing out blanket statements i'd say its even more important on factory rifles which will more likely be used for hunting or have less extraction capabilities. nothing worse than going hunting and your cases not fit in your rifle because they have been fired a couple of times or breaking the bolt handle off because your base has gotten big and you have no extraction. FL sizing isn't about accuracy- im sure if you took a bunch of examples and averaged them all in you couldn't tell the difference in the 2 except in gun handling ease causing better accuracy.
Actually, I agree that "it's all about case fit" and why in my factory barrel that neck sizing (along with other prep details, like shoulder bumping) has been working better for me than FL sizing in terms of more consent results for target shooting. And I have compared this on more than one occasion, but only with this one barrel and chamber. In trying to understand why, I figure/guess it simply has to do with just having a better/snugger fit that better maintains consentricity with the chamber.
Now, when one is talking about hunting . . . FL sizing seems to me to be a very prudent thing to do, for some of the reasons you so well point out.
Please can you clarify for me the "difference" between FL sizing and Shoulder Bumping.
I've been looking at comments and countless videos, but to me, I still cannot see how you can "shoulder bump" only, without actually doing a FL sizing as well. So perhaps I just missunderstand the terms in that Shoulder Bumping is FL sizing PLUS a bit more? Shoulder Bumping always "sounds" like it is LESS than FL sizing, but that part - if true - I cannot replicate myself using my Redding competition set with the body die and competition shell holder set.
He should use twice fired brass to check shoulder bump, some times once fired isn't completely blown out, or uniform from piece to piece.
The more you bump the shoulder the more full length sizing you have. The die has taper and the farther you run the case in the die, the smaller it becomes. They are both full length sizing. Depending on loads and hardness of brass, some need more shoulder bump. Usually about .002 is enough and the less you size the brass the longer it lasts. I have never saw a loss of accuracy with more bump then .002.
The other problem that occurs if you bump too much is stretching the case body and possible case head separations. Matt
rebs
It really depends on if your rifle shoots better with more or less tension . Some bench shooters soft seat , meaning the case has so little neck tension they seat the bullet long and let it seat itself when chambering . I didn't like that method , my rifle shoots better with .003 - 4 . There is no right or wrong in neck tension .
It really depends on if your rifle shoots better with more or less tension . Some bench shooters soft seat , meaning the case has so little neck tension they seat the bullet long and let it seat itself when chambering . I didn't like that method , my rifle shoots better with .003 - 4 . There is no right or wrong in neck tension .
So my "understanding" is thus correct - shoulder bumping is actually FL sizing your brass MORE than what just a "normal" FL sizing setup on your die will do.
I base this on what you say above as well as what I've seen myself when following instructions on how to setup for shoulder bumping - specifically using the competition shell holders:
1 - Setup FL/Body die to touch the ram and perhaps even a little more to ensure a proper cam-over ( on a cam-over type of press).
2 - Incrementally increase the shell-holders in .002" increments from that point until you detect the bolt can close without any resistance.
This is what is puzzling me, since every time I read something on shoulder bumping the impression is created that you are working your brass LESS when shoulder bumping than a "proper" FL sizing, yet I see the opposite?
Common. Bushing dies resolve the problem or Lee collet neck sizing die.
Spring back of the brass is in a different direction between RCBS & Lee. RCBS in, Lee out.
Aim for .002" neck tension. Measure neck OD before and after seating a bullet..
Lee provides some good info on use of their products.http://leeprecision.net/support/index.php?/Knowledgebase/List/Index/13/product-support
Dusty Stevens
Shiner
A bump die is a term that has confused people over the years since it was introduced. Its when you take your actual chamber reamer and run it into a die blank short. You can bump the shoulder back but not size the body. This was commonly used for trying out a wildcat design without spending the full coin on sizing reamers and custom dies
Typically, when one does FL sizing Shoulder Bumping takes place as part at the same time with the die set up properly. Shoulder bumping can also take place when sizing necks with a bushing neck sizing die like Forster's (see: https://www.forsterproducts.com/pro...ing/bushing-bump-neck-bench-rest-sizing-dies/ ). I have this die and I would get too much run out (more than I like, anyway) when using the bushings . . . even when I had Forster check them out and polish them. So now, I simply use the die without the bushing and of course without the expander ball where I'm only bumping the shoulder back by .002 after I've neck sized with a Lee collet die.
BTW: I always to the neck bumping only as the next to last operation to get uniformity with all the brass as my last step is trimming with a Giraud Tri-Way trimmer since the trimmer uses the shoulder as a stop. This way I get consistent case lengths with speed.
Yes, FL sizing works the brass much more than just shoulder bumping and/or neck sizing. With FL sizing, you're squeezing the whole case from the web up making it smaller in diameter (reason why there's less case capacity in a FL sized case vs a neck sized one). That squeezing process "works" the brass and through subsequent firings makes the case walls thinner as the brass "flows" during firing.
Neck sizing with a shoulder bump only works the neck and shoulder and if one doesn't anneal, those areas area will get "worked" more quickly unless one is annealing to keep the neck and shoulder softer than the rest of the case to get more consistent results on paper.
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piie,
I think of shoulder bumping as setting the die (full length or body) to size the case a specified amount, e.g. 0.002”, rather than simply turning the die, until it touches the shell holder plus ¼ turn.
Cases resist sizing in varying amounts, so simply adjusting the die off the shell holder yields varying case head to shoulder (datum) lengths.
The Competition Shell Holders have incrementally more deck height, allowing one to size a case a desired amount less than would be done using a standard shell holder (0.125” deck height). Setting up for cam-over ensures consistent results.
I prefer measuring a fired case using a caliper and comparator such as the Hornady Headspace Gauge then selecting the shell holder to size the case to the desired length.
Here I have edited your procedure using the feel of bolt closure:
1 - Setup FL/Body die to touch the + 0.010” shell holder plus enough more to ensure a proper cam-over (on a cam-over type of press).
2 - Incrementally decrease the shell-holders in .002" increments from that point, until you detect the bolt can close without any resistance.
You really need to measure the OD of a loaded round, most prefer a minus of .002
This is why people use a bushing die to ensure a good fit rather than leaving up to the Die manufacture to tell you what you want.
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