Neck sizing vs full case sizing

[nyyankeedr]

Stupid question here...When only neck sizing is it to be expected that the cases will not fit perfectly into the cartridge gauge? I am referring to 308 brand new brass, which I fired, so now once fired. Hornady 308 cartridge gauge. The cases I fully sized fit as if from factory. The ones I only neck size fit but are snug, and I have to tap them back out from the the other end.

 

[D-4297]

Yes ; because the case is made to fit a SAAMI specification for diameter and lengths , and once it is fired in a chamber , it has been expanded , if only slightly on any or all of the dimensions . The case you have full length re-sized has been , for the most part , returned to manufacturers dimensions . Cases are made to fit within the SAAMI specs to be able to fit "all" chambers of that caliber , of standard manufacturer of the rifle caliber .

 

[cheek9075]

If you are only neck sizing then you will at some point have to push back the shoulders so the case will fit the chamber.

Fire the brass a couple times and only neck size. Then measure the shoulders and adjust the die to set the shoulders back a couple thousands. At this point you are not setting the brass to factory sized brass, but setting the brass to fit your chamber by only a couple thousands of an inch.

 

[nyyankeedr]

See, ask a stupid question and sometimes you get excellent answers. Thanks!

 

[Big Mc]

See, ask a stupid question and sometimes you get excellent answers. Thanks!

Sir the only stuptd question . Is the one NOT asked. You are fine. Just my two cents. Tommy Mc

 

[jepp2]

When only neck sizing is it to be expected that the cases will not fit perfectly into the cartridge gauge?

Kind of depends. I find the Wilson case gauges are cut larger on the diameter. So you can usually insert a neck sized case and it will drop out. Not so on Lyman case gauges. And I find that the burrs on 223 case heads can give you false readings. So I always insert the case head first to check for burrs before I drop it in mouth first.

You do realize the current thinking tends to favor FL sizing over neck sizing. But you are free to do as you choose.

 

[Bill K]

The age old question. Some very serious shooters claim neck size only, 90 % of the time, then FL when they need a bump. Other's say FL each time. Comes down to what you find works best for you and your style of shooting and firearm chambers.

 

[jackson1]

I regularly neck size, but it can bite you in the butt. Anecdotal evidence leads me to believe it works in factory chambers. Monday morning made a trip to the range with a non factory chambered rifle in 25-06, only to discover my rounds would not chamber. Grabbed the ammo for my son's factory rifle, so I was out of luck. Fortunately it is only a 10 minute trip to the range. Another neck sizing draw back could be galling the lugs on your action if you do not monitor and correct your sizing after a couple of firings and you try to force feed.

 

[Straightshooter1]

Stupid question here...When only neck sizing is it to be expected that the cases will not fit perfectly into the cartridge gauge? I am referring to 308 brand new brass, which I fired, so now once fired. Hornady 308 cartridge gauge. The cases I fully sized fit as if from factory. The ones I only neck size fit but are snug, and I have to tap them back out from the the other end.

I routinely do neck sizing on my .308 cases (though I also routinely bump the shoulders) and have no problem with the cases fitting perfectly into my Lyman cartridge gauge. And though I typically use Lapua and Peterson brass, I have use various other brass (a lot of Federal) and have had no such issues with any of them in a factory barrel or the Krieger barrel I'm now using.

What comes to my mind is that it sounds like the size of your chamber might be a little larger than SAAMI spec where you're getting cases slightly larger in diameter after firing . . . just enough to stick a little bit. So, you might try chambering a case that you've neck sized to see it it'll chamber easily enough (using your rifle's chamber as your cartridge gauge). Otherwise, you might just want to stick to FL sizing as that's NOT a "bad" thing.

 

[M-61]

(though I also routinely bump the necks)

Lost me here.

 

[Straightshooter1]

Lost me here.

I miss spoke, I meant to type "shoulders" instead of necks.

Too often I'm thinking ahead of what I'm typing and then don't do a very good job a proof reading. Since I use a Forster Bushing Bump Neck Sizing Die for that, that's probably what was in my mind.

Thanks for the heads up.

 

[BoydAllen]

The age old question. Some very serious shooters claim neck size only, 90 % of the time, then FL when they need a bump. Other's say FL each time. Comes down to what you find works best for you and your style of shooting and firearm chambers.

This is not the case, at least in competition, which is the standard by which we should probably judge the effectiveness of procedures. One issue is that many only have experience with factory chambers and dies that over work cases. Smart shooters of bolt action rifles match their dies to their chambers and adjust the dies so that when a case is sized it is only reduced in size by a very small amount. This is entirely different from what happens with typical factory dies, sizing brass from factory chambers.

 

[David Milisock]

See, ask a stupid question and sometimes you get excellent answers. Thanks!

I have some 6MM Remington cases that have been fired 25 or mone times in my Remington 700. I never did anything but neck size them. The necks get brittle and crack and I recycle them.
Once fired I never full length size them again. Load pushes a 75 grain VMAX at 3,900 FPS.
I have a Howa 1500 in 223 that gets the same treatment. Haven't had the cases long enough to trash any, maybe 9nly 15 to 20 firings. Load pushes a 40 grain VMWX at 3,900 FPS.

 

[INTJ]

Neck only sizing is an old method that most-- if not all--serious competition shooters have moved on from. Everyone I shoot with and know in LR BR bumps the shoulder.

The arguments we have are: do we bump shoulders .002" or .003"? Should we small base every time? Should neck clearance be .003" or .004"?

LR BR shooters make no compromises when it comes to the ultimate in accuracy at longer ranges. Yet over the years we have actually increased case to chamber clearance as our groups aggs continue to get smaller.

F-class shooters like to bump the shoulder as well. Don't even ask @Erik Cortina about neck-only sizing........

 

[BoydAllen]

Neck only sizing is an old method that most-- if not all--serious competition shooters have moved on from. Everyone I shoot with and know in LR BR bumps the shoulder.

The arguments we have are: do we bump shoulders .002" or .003"? Should we small base every time? Should neck clearance be .003" or .004"?

LR BR shooters make no compromises when it comes to the ultimate in accuracy at longer ranges. Yet over the years we have actually increased case to chamber clearance as our groups aggs continue to get smaller.

F-class shooters like to bump the shoulder as well. Don't even ask @Erik Cortina about neck-only sizing........

The amount that you should bump shoulders depends on the application, and the consistency with which your brass bumps at a given die setting.

If you are a Benchrest shooter and your brass is such that setting your die to bump .001 or less gives a consistent feel from chambering those cases, then you have enough clearance, and that much or even less will work fine, but if your brass is such that setting to that amount does not even bump some of the more work hardened cases (or the factory annealing is not that consistent), so that the amount of bump that you get from a die setting varies by several thousandths, then you will have to screw the die in slightly so that the hardest case is bumped a minimal amount.

In this I am just discussing bolt action rifles, since semiautomatics require a looser chamber to loaded round clearance.

In all of this, we need to remember WHY we bump shoulders. There is really only one reason, which is to provide clearance. If a case already has clearance shoulder to head, then there is no need to increase that clearance. an example might be the typical once fired case, that usually will not be tight in its head to shoulder dimension.

If we repeatedly use a die setting that over bumps shoulders we will inevitably cause cases to have incipient separations, and if we ignore that, cases will separate in front of their heads.

On the game hunting side, I would suggest removing the firing pin assembly from the bolt, and running all of your ammo through the rifle to test for fit and function, so as not to have an unexpected feed or chambering problem spoil an expensive hunt.

 

[Intheshop]

"Part" of the issue is the assumption that it's always a full power loading,referenced either/or.

 

[cw308]

My Rem.700 in 308 is my benchrest rifle , blueprinted , bedded , match barrel and Jewell trigger set at 10 ounces . I was neck sizing , changed to Full Sizing with the Redding Competition shellholders . You could size your cases from zero , .001 2 or 3 on up if you want. Never have a stiff bolt lift and all the cases are sized exactly the same . I would suggest .002 for bolt action no more or less. The shoot more accurately then neck for me.

 

[INTJ]

The amount that you should bump shoulders depends on the application, and the consistency with which your brass bumps at a given die setting.

If you are a Benchrest shooter and your brass is such that setting your die to bump .001 or less gives a consistent feel from chambering those cases, then you have enough clearance, and that much or even less will work fine, but if your brass is such that setting to that amount does not even bump some of the more work hardened cases (or the factory annealing is not that consistent), so that the amount of bump that you get from a die setting varies by several thousandths, then you will have to screw the die in slightly so that the hardest case is bumped a minimal amount.

In this I am just discussing bolt action rifles, since semiautomatics require a looser chamber to loaded round clearance.

In all of this, we need to remember WHY we bump shoulders. There is really only one reason, which is to provide clearance. If a case already has clearance shoulder to head, then there is no need to increase that clearance. an example might be the typical once fired case, that usually will not be tight in its head to shoulder dimension.

If we repeatedly use a die setting that over bumps shoulders we will inevitably cause cases to have incipient separations, and if we ignore that, cases will separate in front of their heads.

On the game hunting side, I would suggest removing the firing pin assembly from the bolt, and running all of your ammo through the rifle to test for fit and function, so as not to have an unexpected feed or chambering problem spoil an expensive hunt.

The thought of one LR BR competitor and recent National Champion is that a .003" bump acts as sort of a damper as the case stretches under firing. He thinks brass so sized is this more forgiving of variances in the other components. He has the results to make his idea worthy of consideration.

Another competitor I know that does very well and develops a lot of accuracy enhancing tools thinks that anything over .002" is too much and sort of re-fireforms the brass each time it is shot.

The one thing virtually all LR BR shooters agree on is that a case that is too tight and causes sticky bolt lift messes up tracking. Messing up tracking, especially during 10-shot strings, can put you out of the micro-condition and open your groups well beyond your tuning.

 

[cw308]

The problem with tight bolt lifts is , it creates too much wear on your locking lugs after awhile , .002 seems to be the sweet spot for me , never had a hard bolt lift . It also depends on how your seating your bullets , with a touch , jump or jam .

 

[K22]

I'll try not to repeat what's already been said. (My remarks are based on bolt action rifles only.)

The OP mentions Hornday Cases. I've had new unfired Hornady cases that are above the upper step on a Wilson Case Gauge seemingly indicating that the cases are too long in head space. This may or may not be true for your rifle. The only way to know is to check the case in the rifle to determine the amount of resistance to chambering the case. Removing the cocking mechanism from the bolt enables a better "feel" for the amount of resistance to close the bolt.

With my rifle, the new cases had to have the shoulder pushed back to provide optimum chambering. The lesson here was just don't assume the new unfired cases meet SAMMI specs which is what the Wilson Gauge attempts to measure(i.e. the case should fit between the upper and lower steps of the gauge.)

This in not an indictment of Hornady cases. In fact, I like them a lot and use them extensively. After the first firing and setting up my FL sizing die for a .001 to .002" shoulder set back, I'm completely satisfied with my reloads both from an accuracy, consistency, and functioning standpoint.

Since I'm primarily a precision varmint / predator hunter, I full size my case with a slight shoulder bump to ensure flawless chambering. When I began reloading in the late 60's it was widely believed (published) that neck sizing improves accuracy and extends case life over that of full sizing. That's probably true if you full size cases improperly but if sized properly for optimum fit of your rifle's chamber then these assertions are not true at least in my experience. I've sized and shot thousands of rounds both ways and I can attest that full sizing, done properly, does not reduce case life or degrade accuracy. The benefits of full sizing are improved functionality and less wear on the lugs.

The key is to learn how to full size properly which means you need a bump gauge and a caliper to measure the fired case head space so you can adjust your die to set the shoulder back just enough so that it chambers with only slight resistance which typically means a .001 to .002" shoulder set back

The OP is might want to read the article on the Redding-reloading.com web site by Todd Spotti entitled "Dealing with Headspace" which does a better job explaining this than me.