Neck Sizing versus Full Length Sizing Questions

[ThePretzel]

I'm a bit new to reloading, and I had a couple of questions about the differences between neck sizing and full length sizing. I'm currently using just the standard Hornady full length sizing die (6.5 Creedmoor) on my brass, but I have heard several potential advantages of neck sizing that I wanted to get some information on (as well as downsides).

Neck sizing does increase the effective life of each piece of brass, right? This is one of the big reasons I was thinking of purchasing a neck sizing die, so that I could purchase some more expensive brass and not feel like I might have issues at only 5 reloads like I've had with some Hornady brass.

Is neck sizing more accurate, or is that more of an urban myth? I have seen conflicting reports of whether neck sizing will increase accuracy or muzzle velocity, with some stating that it will do both, some stating it will only do one of the two, and others saying that there's no real difference in performance between full length and neck resizing.

Is it true that you don't need to lubricate your cases if you're only neck sizing?

If I begin to neck size, will I need to full-length resize every so often? I've heard people talk about the shoulder moving when they use neck sizing dies and "bumping the shoulder back", but I'm not quite certain what they mean exactly.

If it can extend the life of my brass without hurting the performance (and speeding/cleaning up the reloading process, if I don't need to lubricate the cases) or running into some other issues, I'll definitely look into purchasing a neck sizing die. Is there any specific brand of die that would be recommended? I've had my eye on the Redding Premium 3-Die set that looks to have their micrometer seating die, a full length die, and a neck sizing die as well, but I wasn't sure if there was a different recommended die set or just single neck sizing die that would be recommended (I currently just use a RCBS seating die and with my Hornady full length sizing die, so I know they're not exactly the highest quality).

 

[Supersubes]

Your rifle and ammo need to be reliable and accurate. Under no circumstances should you be putting brass life in front of either of those things. It is a myth that fl sizing kills brass life. It is true that improperly FL sizing (aka: over sizing) is very detrimental to brass life. Neck sizing is not more accurate, and I would actually argue the opposite.

Every piece of brass does not react the same, even when fired with the same load in the same gun. So you end up with fired cases that are larger than one another. In any batch of cases you have one or two that chamber hard. Next firing it’s more, then more. The neck sizer has to choose when they go through and fl size them all. In my observation, it seems like they always wait too long. You can always spot a neck sizer on the range. They’re the ones muscling their bolts open and closed due to the oversized cases.


most guys here are FL sizing. Using Hornady brass, the fail point seems to be the primer pockets wearing out and not holding a primer, an issue not related to sizing at all. A lapua creedmoor case flat out will not loosen a pocket without going nuclear on the load. Furthermore, they last a long time in every other way, while being FL sized. I’d wager that the lapua would last several times longer than Hornady, making it cheaper, not more expensive. You’ll probably need to anneal to fully realize that life. I use Redding and Hornady creedmoor dies (I have full sets of each). The Hornady match die set works great, and are reasonably priced.

 

[ThePretzel]

You’re rifle and ammo need to be reliable and accurate. Under no circumstances should you be putting brass life in front of either of those things.

While that is certainly true in an idealized scenario, I am currently shooting on a college budget so I prioritize cost per reload over accuracy within reason (my reloads are currently shooting under .3 to .6 MOA 5-shot groups, which certainly equals or surpasses my skill as a shooter in most imperfect scenarios).Brass life is a factor to me for this reason even if not as important as reliability or good accuracy.

It is true that improperly FL sizing (aka: over sizing) is very detrimental to brass life. Neck sizing is not more accurate, and I would actually argue the opposite.

I'm curious, what constitutes over sizing? This is a question just to help expand my reloading knowledge since I haven't heard this term before.

As far as the points you make about neck sizing, those are things I hadn't heard about neck sizing. Does case trimming solve those issues that you say neck sizers have, or is it a matter of the shoulder moving and changing the headspace of the casing?

Furthermore, they last a long time in every other way, while being FL sized. I’d wager that the lapua would last several times longer than Hornady, making it cheaper, not more expensive. You’ll probably need to anneal to fully realize that life.

That's good news to hear, since I had heard stories of people who only got 5-10 reloads out of Lapua brass when they were full-length resizing. I wouldn't want to purchase Lapua brass if it lasted no longer than my current brass under the same reloading conditions, but if it does last that much longer that the investment would start to make sense for me (considering I can buy sub-moa Hornady ammo for $.75 a round compared to the $1.00+ unloaded for Lapua brass).

I was planning on annealing once I had higher quality brass. It didn't seem like much of a benefit for my Hornady brass since the issues I was having between 5-10 reloads was blown primers in fairly relaxed loads that showed no pressure signs up to that point (40.9gr H4350 under a 147 ELD-M gives me best accuracy, Hornady factory load is 40.5gr), but if the primer pockets are a non-issue on Lapua brass then extending the life of the neck would be a concern.

I use Redding and Hornady creedmoor dies (I have full sets of each). The Hornady match die set works great, and are reasonably priced.

Do you have any preference between these two brands of dies? I'm not opposed to spending the extra money on the Redding dies (since it's something I forsee myself using for a long time) if they are better quality or produce better results than the Hornady dies. Specifically it seems like the micrometer seating die would make precisely adjusting CBTO much easier and more repeatable from time to time (as it is with my RCBS die I have to guess and check in small increments until I reach the desired length each time I reload), and the Hornady match seating die appears to roll crimp (I don't know if that's good or bad, but it seems to be a difference).

 

[Supersubes]

Any fl sizing die should be able to size a case down so that case will fit in any chamber, even if that chamber is at the small end of the spectrum. These are just industry tolerances, so things work together. What is key for you, is that you’re only sizing the case enough to fit back in your chamber. You have no control over the diameter dimensions of your FL sized case, but you can control the resulting headspace dimension by controlling how far you push the case into the die. Generally, if you’re screwing the die all the way down onto the shell holder during setup, you’re likely oversizing. Repeatedly pushing the shoulder back too far and firing the case, over works the brass. This almost always shows itself in a near or full case head separation(google it).

Anybody killing lapua cases in 10 firing is doing something wrong. If they’re enlarging pockets in lapua creedmoor brass, they’re loading way too hot. In fact, if you got to that point, where the pockets were big and it surprised you, you were likely ignoring or just oblivious to obvious pressure signs.


No, case length has nothing to do with neck sizing issues.

Annealing is beneficial always, not just for premium brass. Neck life depends on how much it’s getting sized, just like the rest of the case. You must size it so it will hold a bullet. If your doing a thou or two of neck tension, the overall sizing amount just is what it is. Assuming an in spec chamber neck, annealing will extend neck life almost indefinitely. Tom Sarvers 1000 yd world record group was fired with brass that had been fired sixty something times. Not an apples to apples comparison with you, since he was using a precisely designed chamber with a matching die, but you get the point.


If you wanted to test neck sizing, simply back your die off so it doesn’t touch the shoulder. I highly recommend you purchase a headspace comparator set like the one Hornady sells, if you don’t already have one.

 

[Supersubes]

I don’t believe the Hornady seater has a crimp function. Youre RCBS die should though. I only mention that because like any crimping seater die, if you don’t want it to crimp, dont set it up so the case goes deep enough to crimp.

Im not a huge Redding fan these days. I own many many sets of them. I do find myself buying them occasionally because the cartridge menu is extremely wide, and they’re available. My Hornady match set was 80 bucks. The Redding two dies type-s was 180. Cost aside, id still choose the Hornady. They’re perfectly dimensioned, and have a great internal finish. I cant say that about many Redding dies sets I’ve purchased. The Hornady seater is more rudimentary, but still easy to adjust. As a side bonus, a Hornady 6.5 seater will work on any 6.5 case unlike the chamber type Redding match seater. You can also convert the Hornady to other bore sizes cheaply and easily if needed. If the budget was an issue, Hornady seems the obvious choice. I don’t know which Hornady you have, the standard one with the collet decapper retention, or the match. The match uses the same .5” neck bushings as the type s Redding dies.


Hornady did a good job with the Creedmoor. It was designed from the ground up as a match/tactical precision round. It did not start out as a hunting round, or a military round, and that’s reflected in its tolerances. From the saami reamer specs, to the typical brass dimensions, it’s pretty much a best case scenario for the shooter/reloader, without going custom
on everything(reamers, dies, etc). That is not the case with many cartridges.

 

[ThePretzel]

Cost aside, id still choose the Hornady. They’re perfectly dimensioned, and have a great internal finish. I cant say that about many Redding dies sets I’ve purchased.

Alright then, I'll have to hunt for some of the Hornady match dies to see if I can find them in-stock anywhere. I looked when I picked up my brass today but the 6.5 Creedmoor dies are quite popular right now. Right now the one I have is just their standard full length sizing die, not their match grade die.

it’s pretty much a best case scenario for the shooter/reloader, without going custom on everything(reamers, dies, etc). That is not the case with many cartridges.

That's reassuring to hear, I'll have to see if I can't get bullets through one hole with some tweaking and my new brass once I get ahold of the dies (current best group was 5 shots at .29 MOA).

 

[Supersubes]

The dies you have seem to be working fine. As long as you’re not pushing the shoulders back to far, you’re probably fine. The lapua brass has slightly smaller internal volume, so be prepared to back down the charge a half grain.

 

[ThePretzel]

The dies you have seem to be working fine. As long as you’re not pushing the shoulders back to far, you’re probably fine. The lapua brass has slightly smaller internal volume, so be prepared to back down the charge a half grain.

Yeah, my previous load was 40.9gr so I've got a new ladder test prepared from 39.6gr to 41.6gr for tomorrow so I can take a look and see what the Lapua brass w/ CCI 400's likes best. This time I can actually do it right as well, using a Magnetospeed I did not have the last time I tried different powder weights so I can properly test SD and ES.