Neck sizing

jackthebear

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Mar 12, 2013
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I recently read an article on advanced reloading where the author advises neck sizing only when necessary. I don't get it! Each time you full length resize doesn't the neck get done in the process? And don't you have to resize the brass after each firing anyway?
 
Lots of schools of thought and you'll get a multitude of comments, I'm sure. I just remove the expander ball when I neck size, if I neck size to lessen the impact of overworking the brass. That lessens case growth as well but thats just me.
 
I don't know what is meant by 'neck size only when needed'. I don't know as it's ever needed but it sounds good. Mostof us learn that it's value for both accuracy and case life is vastly over rated. Neck sizing only helps accuracy if the loader is doing a poor job of FL sizing. Cases usually fail with split necks and, on average, common neck dies work the necks as hard as any FL die. (Lee's unique collet neck die does greatly reduce cold working necks so cases do last a little longer, and do it without the fussyness of bushing sizers.)

Real advanced reloaders usually properly FL size and generally avoid neck sizing but virtually every one has to try it and learn the truth for themselves.

Expander balls in conventional dies are there for a very useful purpose and sizing without expanding causes more problems than it solves.
 
To clarify, are you saying to size the neck significantly under diameter and run a ball back up the neck to expand it to proper tension is the best way?


I guess it depends on whether you agree with the experts who write the books or the experts who write on forums. The books all indicate that neck sizing is a proven method to increase accuracy and case life. Proper neck sizing involves bushings to resize the neck to .002 to .003 under the loaded case neck diameter.

I am on the fence regarding this debate. I have done both for 35 years and found my best accuracy with neck sizing only and no expander ball. But that does not mean I have had poor accuracy with FL sizing. I prefer the neck sizing process at this point but it might be due to how easy it is vs any thing else.
 
don't you have to resize the brass after each firing anyway?
The author is telling you that you do not have to FL size, and with a few things qualified he's correct. You should go back and re-read the article while paying attention to the details in it.
 
In my case, only the real expensive (initially) cases get multiple reloadings. The others might get reloaded 2 times and the very outside 3, because of the sheer numbers of cases I own or acquire for the group or the group owns.

I relegate my bottleneck cases to basically a couple calibers and ask the rest of the group to do the same barring the other rifles that usually don't go through numerous firings.

Typically, I'm loading 308, 223 (5.56) and WSM with frequency and thats it.

Straight walled cases are another animal because we are all pistol shooters and we all compete in various leagues so 44 Remington Magnum, 45 Auto, 44 Special and 357 Magnum cases get reloaded numerous times but a straight wall case (that headspaces on the rim) presents much less of an issue and becaue the charge is less and the pill is less, they are more economical to shoot, plus, there are some lever guns in the group and soon to be another (mine).

One just has to be cognizant of how much you bellmouth the end for pill insertion because thats the only area the brass really gets worked and consequently work hardened. Match chambered 45's in 1911 Nationaql Match Pistols require careful resizing because chambering can be an issue. Colt National Match 45 Auto's as well as Kimbers are very carefully machined and of course you pay for that. The group has 4, I own 2 myself.

I realize straight walled pistol cartridges aren't germane to this forum but if you own pistoil, either semi auto or relvolver, at some point in time you'll probably reload those too.

Candidly, I don't own one bshing die and I don't ever plan on getting any. I do, however, refrain from purchasing less expensive dies.... Like Lee. Lee dies sets are fine for what they are but again, yoiu get what you pay for. Redding, Forrester and even RCBS Gold Medal Match Die sets are more expensive for a reason (not just so the maker makes more profit). All the above parameters that apply to chambers apply to die sets as well. Wilson also manufactures excellent dies but Wilson dies aren't designed for reloading press loading (arbor press instead).

In Lee Precision's defense, I do use Lee Factory Crimp dies on all my semi auto bottleneck rounds despite the end use by the group. Some get used in bolt action rifles. some in gas blowback. I like to actually crimp everything bottleneck and the Lee Factory Crimp Dies make that easy to adjust the crimp and will crimp to a cannelure or no cannelure.

I do bump shoulders when the need arises (for an individual chamber) but I modify the dies ( by removing a couple thousands of material at the base, jigged vertically in on a surface grinder) to allow the die to bump but still resize everything else. Thats just a matter of utilizing the die by adusting the ram stroke in relationship to the shoulder datum and measuring the datum by conventional means using a headfspace gage.

I try to always get the group to segregate individual loads for individual rifles (or pistols) because each chamber has a unique set of dimensions. No two chambers will be exactly identical, even if machined in sequence and thats the result of many factors not limited to tooling wear, boundary lubrication as it pertains to the machining operation, ambient temperature in the machining enviroment, feed rates for tooling and allowable/acceptable tolerances as required by the print. Even the quality/ridgidity of the machine tool comes into play. TIR of any spindle will adversely impact of how the attached tooling cuts, so lots of varibles are at work, constantly.

Whether I get a box of empty casings from Linda or Bill or Tom or Rod or Jeff or Cy or myself, each box is labeled for the firearm used in, the number of times loaded plus the pill and powder charge and the jump if applicable) and when reloaded, go back in the same box and the data is updated. BTW, I learned a long time ago that girls are better at shooting than guys are. Linda can outshoot any of us, especially when it comes to pistols............:)

Just like rifling in the tube. No two barrels will be exactly the same. Thats how forensic technicians can ascertain what firearm discharged a bullet by matching the engraved rifling marks on a pill to a certain barrel. No two barrels engrave the exact same pattern and no two chambers are exactly, dimensionally alike.

Machining tolerances (and chamber internal dimensions) can vary greatly across a certain caliber family. As a rule of thumb, the more costly the firearm is, the tighter tolerances it's machined to. You don't changeout tooling or exercise as much care when machining a cheaper firearm versus a more expensive one, thats just economics of manufacturing, despite what the maker claims.

Fireforming gives you the closest impression to that particular chambers internal dimensions but you still must maintain proper headspace and shoulder datum to chamber internal set back dimension which is whay I like to practice segregation of brass and utilize a headspace gage when things get tight and they will get tight at some point due to factors such as case growth and even internal carbon fouling. Not everyone cleans their chamber and bore and removes carbon buildup every cleaning, perfectly.

I won't even mention bullet jump or neck tension/turning...lol

Thats how I do it and my procedures may or may not work or apply to your scenario. Just relating my SOP, nothing more. I may be FOS but that works for us and has worked for a long time. Many years before I even started posting on any forum.
 
Glad this topic came up and I've been considering moving towards neck sizing only. Just this week I was wondering if I could send all of my FL sizing dies back to factory and have them ream and convert to neck size only. Here's my thoughts and experiences:

FL sizing is a good thing when done properly, taking note of shoulder bump. I use RCBS precision mics for this. We all know the neck is sized during this process.

If in fact I cater to my laziness, I'd much rather just neck size and forgo all of the case lube crap and extra cleaning of the cases. Which is what I'm seriously considering. But if I do, then I wonder what will happen that day in the field when I have a feeding issue on a neck sized only loaded round. That is the one thing that has kept me from neck sizing only all of these years.

I can't see how this can't be a fact but if indeed neck sizing dies are used, there is certainly less work hardening on the cases and if less work to the brass means longer reloads, then it must extend the usefulness of the brass.

As to bushings and Lee collet dies, never had either. I chose to send my size dies back to manufacturer and have them hone the necks to .003 less than a loaded round. No collet or bushing needed. When the case is fired, it's going to expand the neck to the chamber dimension and only half of my rifles are "tight-necked." So, at the moment, my case necks when fired and sized still do not get near the work hardening they did prior to the modification when using a button. But the body still gets worked.

As to buttons in the sizer die. The ONLY use I have for them is virgin brass. I take the extra step. I size all new brass with the button to ensure consistency to whatever level that batch of brass allows. Then take the button out and do it all again where neck is reduced again. Then trim all, flash hole debur, and they are ready to go.

All fired brass gets sized w/o the button. No need for it and it only runs the risk of introducing runout.
 
I guess it depends on whether you agree with the experts who write the books or the experts who write on forums. The books all indicate that neck sizing is a proven method to increase accuracy and case life.

Depends on which books you've been reading. Frankly, I don't know any successful competitive shooters who neck size, including (literally) the best in the world. Most of the writers who put such stuff out wouldn't be caught dead at such shoots, and have no idea what they're talking about. When Ohio Ordnance came out with their M1918A3 semi-auto BAR, one of those same gun writers (very well known, and from one of the more prominent gun magazines) promptly declared that it'd be, "the perfect rifle to use in Service Rifle competition at Camp Perry." The guy clearly had no idea what constitutes a Service Rifle, has never attended a high power match of any type, and probably couldn't even find Camp Perry on a map.

Sticking to those who both write, and actually compete (a very small club, I assure you), you'll never hear any of them recommend Neck Sizing.
 
Kevin...

Camp Perry is where the wind always blows the wrong way, it's cool in the summer and the shadow of the N-Plant is on the close horizon. (I go by there regularly on my trips from Cleveland to Toldeo...)

I think sometimes neck sizing dies are just put in reloading sets to take up room in the box...........:)
 
I neck-size for all my bolt-action rifle calibers. My only single-shot is a .45-70 1874 Sharps, and the others are lever-actions, and those get FL sized.
 
Sidecarflip,

I'm pretty sure Murphy includes them in die sets, specifically to catch the unwary, and create alibi relays on those same Lake Erie shores of which you speak!
 
To clarify, are you saying to size the neck significantly under diameter and run a ball back up the neck to expand it to proper tension is the best way?

I guess it depends on whether you agree with the experts who write the books or the experts who write on forums. The books all indicate that neck sizing is a proven method to increase accuracy and case life. Proper neck sizing involves bushings to resize the neck to .002 to .003 under the loaded case neck diameter.
I agree with the folks winning matches and setting records and getting best results testing bullets for accuracy

With bottleneck cases headspacing on their shoulder, the case neck and the bullet in it are centered in the chamber based on how well centered the case neck is on the case shoulder. With such ammo, the case shoulder's hard into and well centered in the chamber shoulder when the round fires. In line ejectors push it there before the firing pin drives it there when it fires. The case body doesn't touch the chamber at all except at its back end where it's pressed against the chamber wall opposite the extractor on the case head. The case neck floats in space in the chamber neck. How well the bullet aligns with the bore is decided by how perfectly centered the case neck is on the case shoulder.

Full length sizing dies with neck diameters a couple thousandths less than a loaded round's neck diameter best center sized case neck on shoulders. They hold the neck sizing part of the die well aligned with the body of case centered in the die body. Neck only sizing dies don't do that. Tension's determined by how much smaller the sized case mouth is than bullet diameter.

Few top ranked, match winning and record setting rifle shooters write books. Nancy Tompkin's one of them. She, her husband Middleton and daughters Michelle and Sherri have probably won more matches and set more records that any other group of four people on this planet. They've been doing it with full length sized bottleneck cases for decades.

Sierra Bullets' been full length sizing all their cases used to test their stuff for accuracy since the 1950's. I doubt anyone shoots their stuff more accurate than they do. Most benchresters switched over to full length sizing their cases a few years ago. While their smallest groups stayed the same size, their largest ones shrank quite a bit.

I've observed over the years that brand new cases, both rimless and belted ones unprepped in any way, typically shoot bullets more accurate than any neck only sizing ones do. But I judge accuracy by where all shots fall, not just a small cluster of a few of them dead center in a larger group of shot holes. Any fired case sizing process will sometimes put a few shots in the smallest group their maker has ever seen.
 
Good info. I don't shoot bench, my sanity is already questionable, as that would end it for sure. And I don't write books, I can't read. I guess I am ok with .5 MOA or less and for some reason, probably luck, I get that. LOL

I am not set in my ways on this issue at all. Perhaps for the average joe you can go either way and be fine. I still don't like the amount of work my brass goes through with a RCBS gold FL die and ball. It hammers the neck one direction and then pulls it the other. So the middle option is something like a forester perhaps that FL sizes with bushings for the proper tension?
 
So the middle option is something like a forester perhaps that FL sizes with bushings for the proper tension?
If all your case necks have the same wall thickness within .001", I'd have your full length sizing die's neck honed out to .002" smaller than a loaded round's neck diameter. Some die company charges for doing this are way less than 20 bucks.

I don't like the bushing full length sizing dies as they don't size the case neck all the way back to the shoulder but instead stop short 1/16 to 1/32 inch. Their makers claim that's done so the unsized portion of the case neck helps align it in the chamber neck. That's not reality in my opinion; that part of the case is smaller in diameter than the chamber neck therefore no way does it help center the case neck; it's the case shoulder in the chamber shoulder that does that. And their bushings are a bit loose in the die so they can get off center from the case body axis when the neck's sized. However, bushing dies from RCBS and Redding are probably the best ones out there commercially; Sierra uses Redding ones on their cases they'er made for and get great results.

Then decap fired cases separately in another die and toss that die's expander ball someplace.
 
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