Is collet better than full length?

[Lovesbeer99]

I've always used full length sizers for my rifles. Is there any advantage to use a collet neck sizer? Why bother?

 

[Winston_Smith]

I am still a newbie but my understanding is that neck sizing is easier on your brass and results is more accurate ammo due to maintaining the fire formed dimensions.

If you plan to use the ammo in multiple rifles or auto loaders, full length sizing is the way to go.

 

[psyop]

Neck sizing only is primarily for Bolt Rifles using brass specifically for that rifle.
Of course the shoulder may need to be bumped back at some point by either a Body Die or FL Die

Use FL die for Auto Loaders. I still use a Collet Die on my FL sized cases for more consistant Neck Tension.

 

[FROGO207]

I pretty much full length size for all my rifle loading, this is coupled with annealing the brass after every three reloads serves my needs well.
BTW I anneal by using hot lead and dipping the brass. this is described by myself and others in another thread here.

 

[something vague]

FROGO207,

Have you got a link to that method of annealling? Also, what part of MDI are you from? I'm right across the bay in Lamoine and actually do most my work on the island. Your the first person I've seen from any part of Maine on this board.

 

[Grumulkin]

1. Just neck sizing should prolong brass life.

2. Lee Collet Dies may produce as accurate ammo as other full length and neck sizing methods but I've had instances in which they produce less accurate ammo.

 

[psyop]

I've had instances in which they produce less accurate ammo.

I am convinced, after years of testing that all of my less accurate ammo is my fault. YMMV

 

[Steve C]

Neck sizing for a particular rifle is also advantageous for guns that have a generous or oversize chamber that stretches a standard case much. Lee Enfields are one type of rifle where you can get many more reloads by neck sizing with collet die or other neck sizing die where if you full length size the case you wind up working the brass so much that it can crack after just a few resizing operations.

 

[prickett]

When I asked on the bench rest forums what sizing die to get for best accuracy I got a surprising number telling me to get the Lee. I'm very happy that I did. Collet dies extends the case life, do not require any case lube, and seem very accurate to boot. Oh, and they are very inexpensive!

 

[twofifty]

With a collet or other neck-sizing die, its a good idea to give the neck a quick go with a caliber-sized brush, esp. if you have powder residue or grit from pickups.

 

[LTR shooter]

Collet dies extends the case life, do not require any case lube, and seem very accurate to boot. Oh, and they are very inexpensive!

Yep , I was pretty skeptical that this "budget" die could be capable of loading any kind of accurate ammo but for $16 I was willing to take a chance.

A real pleasant surprise to say the least! The accuracy of my loads neck sized with the Lee Collet dies has been excellent! I should have bought this die years ago.

 

[OKIE2]

With dipping brass in hot lead how do you remove the lead afterwards?????????????????????????

 

[Bart B.]

This may surprise you folks but proper use of full length sizing dies produced ammo as accurate as or better than neck sizing. Many groups testing such ammo's been smaller than benchrest records. Example: several 10-shot groups at 600 yards ranging from 1.5 down to .7 inches.

Redding's "S" Full Bushing full length sizing dies using a neck bushing a couple thousandths smaller than loaded round neck diameter is the modern version. Folks used to lap the neck out of standard full length sizing dies to do the same thing.

Sierra Bullets uses these dies (or Redding conventional full length ones) to reload rimless bottleneck cases for testing their bullets. Their best match bullets stay under 1/4th MOA at 200 yards. Not too shabby at all considering they meter powder (not weighed), don't work up loads, test barrels have standard SAAMI chambers and they use these full length sizing dies.

And getting several dozen reloads per case happens. Most I've got is 45 or so with a .308 Win. 'cause I ran out of test powder at the range doing this test with max loads. A friend got 57 reloads on his test case before he ran out of the other part of the powder I shared with him for our tests. Others have gotten more winning matches and setting records along the way.

 

[243winxb]

Is collet better than full length?

Maybe if compared to standard FLRS dies. For accuracy, custom dies are best. You want everthing the same load after load. A neck sized case changes ever time its fired. If you want proof of this, just keep shooting the same case, it will chamber maybe a few time, but soon or later you must full length resize. This mean the body of the case changed with each firing, changing the pressure and how the case sits in the chamber. As said about, a Redding FLRS Type-S Bushing die is hard to beat.

 

[Bart B.]

243Winxb's response to the first post:

Maybe if compared to standard FLRS dies. For accuracy, custom dies are best. You want everthing the same load after load. A neck sized case changes ever time its fired. If you want proof of this, just keep shooting the same case, it will chamber maybe a few time, but soon or later you must full length resize. This mean the body of the case changed with each firing, changing the pressure and how the case sits in the chamber. As said about, a Redding FLRS Type-S Bushing die is hard to beat.

I'm not convinced custom dies are best for accuracy. Especially when the only difference between a full length sized case and a neck only sized one's fit in the chamber when they're fired is miniscule. The back end's center of a full length sized case may be 1 or 2 thousandths of an inch more off chamber center at that point than a neck sized one; neither type are centered at the back end both before and during firing. Both have their front end perfectly centered when fired when it counts. And full length sized cases may well be better centered up front than neck sized ones 'cause cases and chambers ain't perfectly round; full length sized ones will have a smaller shoulder diameter preventing interference at the body-shoulder junction that may happen with neck sized ones.

Peak pressure, if that's what you're talking about, is equal for a given load fired in the same chamber regardless of how the case is sized. Both types of sized cases expand out hard against the chamber inner surfaces at peak pressure regardless of where they started from. Then they spring back a thousandth or two.

Shooting at least 15 to 20 shots per group, I've never got any neck sizing technique to do as well accuracy wise as full length sized ones.

 

[FROGO207]

As I reload for several different firearms and they all tend to be semi or lever type I full length size. I did try neck sizing on my 223 and 308 bolt guns. The long and short answer was that I could not tell the difference if there was one to be seen. It is simpler for me to size them all the same and not have to keep track of what was used in what rifle as I have multiples in the same cart. size. This makes me sound so lazy!

 

[243winxb]

Peak pressure, if that's what you're talking about, is equal for a given load fired in the same chamber regardless of how the case is sized. Both types of sized cases expand out hard against the chamber inner surfaces at peak pressure regardless of where they started from. Then they spring back a thousandth or two.

How about the pressure curve, would the FLRS case rise to the peak slower as it must expand the case first?

 

[Bart B.]

243winxb asks about peak pressure timing:

How about the pressure curve, would the FLRS case rise to the peak slower as it must expand the case first?

Both full length and neck only sized cases, dimensionally, have a small amount of clearance around them to the chamber walls. Neck sized ones typically a thousandth or two less than full length sized ones. They both expand a little bit to make full contact with the chamber walls at peak pressure.

Lots of folks think fired cases have a perfect fit against the chamber walls. They don't because the elasticity of the brass makes 'em shrink back a couple thousandths. That's a good thing as chambers and cases aren't perfectly round so there needs to be a tiny bit of clearance between the fired case and chamber else it would be harder to extract. Measure your chamber's diameters at different points on its body area then compare those dimensions to what the same point on a fired case is. Most folks are surprised at the results.

 

[something vague]

Peak pressure, if that's what you're talking about, is equal for a given load fired in the same chamber regardless of how the case is sized. Both types of sized cases expand out hard against the chamber inner surfaces at peak pressure regardless of where they started from. Then they spring back a thousandth or two.

I disagree! Correct me if i'm wrong but case capacity corresponds (spelling) to peak pressure for a given load. Neck sized only cases get larger with each subsequent firing. Therefore your original load with a flrs case is going to produce a different peak pressure and velocity compared to if you neck size only. And I really don't believe that chamber dimensions have much to do with this other than keeping the case dimension somewhat close to the first time you neck sized. But due to work hardening your case will shrink less and less after each firing, which will increase case capacity a bit. This could potentially produce inconsistant loads through different firings of the same case.

Why is it that seating a bullet in a case such as the 9mm too deep create dangerously high pressures? You have decreased case capacity which in turn will increase pressures for a given load. The chamber dimension of that 9mm will not save that unsafe situation. I guess I don't understand what you're saying Bart.

 

[Bart B.]

My comment:

Peak pressure, if that's what you're talking about, is equal for a given load fired in the same chamber regardless of how the case is sized.

And SomethingVague responds with:

I disagree! Correct me if i'm wrong but case capacity corresponds (spelling) to peak pressure for a given load.

I neglected to include the details of my comparison. Sorry 'bout that; it could cause some misunderstanding. I should have stated that both types of sized cases had the same neck/mouth diameters after sizing.

When I was comparing 190's from a .308 Win. with 20 neck only and 20 full length sized cases using the same load and seating depth, both had their necks sized the same amount. The neck sizing die's bushing was the same diameter as the lapped out neck of the full length sizing die; .332 inch. All the WCC58 cases had the same neck wall thickness. Release tension was the same for both types of sized cases. The only difference in these two loads was body diameter and case headspace; full length sized cases had body diameters about 3 thousandths smaller than the neck only sized cases and full length sized cases had their shoulders set back 2 thousandths from their fired position which was what the neck only cases were. Shooting them alternately through a chronograph while testing for 600 yard accuracy, the averge velocity (screens at 10 feet) difference was less than 2 fps with a spread of about 20 fps for each 20 shot group. Neck only sized cases shot about 6 inches for 20 shots, full length sized ones grouped about 3 inches.

Note that when peak pressure occurs, both types of sized cases are pressing hard against the chamber walls. The inside volume of both types of cases are the same because the chamber's the same. If pressure was different between cases with a few thousandths difference in body diameters and case headspace, then my muzzle velocities in my accuracy tests would have been much greater than 2 fps.

But I agree that seating a 9mm (or most any other cartridge) bullet too deep can cause higher pressure. It's the increase release force needed that causes it more than the smaller case capacity; the more the case mouth grips the bullet the more force is needed to get it moving. I've seated 150-gr. bullets at different depths in .308 cases with their necks sized to the same dimension and got higher muzzle velocities with the deeper seated ones. The deeper seated ones also required more weight (old bullets) in the can wired to a shell holder below a bullet puller holding the bullet seated in a case to check release tension. And seating a bullet in a case full length sized in a normal die but without the expander ball (great force is needed) makes a magnum out of a mouse gun; well flattened primers as well as much higher muzzle velocity. But case capacity's the same as with normal neck tension.

 

[woods]

I've seated 150-gr. bullets at different depths in .308 cases with their necks sized to the same dimension and got higher muzzle velocities with the deeper seated ones.

This is clearly in conflict with Barnes data

http://www.barnesbullets.com/resources/newsletters/september-2007-barnes-bullet-n/

This is a chart of different calibers and the pressure taken with the closest seating of .025" depth on the left for each caliber and increasing by .025" going to the right in most cases. The pressures generally show to decrease with increased seating depth

Here is what Hornady has to say

http://www.hornady.com/ballistics/internal.php

To illustrate the effects of variations in bullet travel before the bullet enters the rifling, we'll compare a standard load with adjustments made only in the bullet's seating depth.

In a "normal" load with the bullet seated to allow about one 32nd of an inch gap (A) between the bullet and the initial contact with the rifling, pressure builds very smoothly and steadily even as the bullet takes the rifling. Pressure remains safe throughout the powder burning period (B), and the velocity obtained - 3500 fps - is "normal" for this load in this rifle.

Seating the bullet deeper to allow more travel before it takes the rifling, as in these next two illustrations, permits the bullet to get a good running start (C). Powder gases quickly have more room in which to expand without resistance, and their pressure thus never reaches the "normal" level. Nor does the velocity; with the same powder charge it only comes to 3400 fps (D).

When the bullet is seated to touch the rifling, as in the accompanying illustrations, it does not move when the pressure is low (E); and not having a good run at the rifling as did the other bullets, it takes greatly increased pressure to force it into the rifling. As the rapidly expanding gases now find less room than they should have at this time in their burning, the pressure rise under these conditions is both rapid and excessive (F). Velocity is high at 3650 fps - but at the expense of rather dangerous pressure.
Many rifles deliver their best groups when bullets are seated just touching the rifling. Seating bullets thus can be done quite safely if the reloader will reduce his charge by a few grains. The lighter load will still produce the "normal" velocity without excessive pressure.

You'll have to go to the website to see the illustrations. But the point is that seating deeper decreases pressure and velocity, probably up to a certain point.

Hornady also says

Though some rifles deliver their best groups when full length resized, neck sizing alone usually promotes better accuracy, because when our reloaded cartridge is returned to the chamber it is almost a perfect fit; headspace is just right with all cases, whether rimmed, belted, or rimless; and most helpfully of all, the new bullet is almost perfectly aligned with the bore.............................................

..............If optimum accuracy and prolonged case life are important to the reloader, our advice is to neck size alone whenever practical. There are of course, situations in which it is advisable to full length resize. Shooters reloading for pumps, lever-actions, and autoloaders must do so to facilitate reliable chambering. A lever-action, for example, doesn't have the powerful camming action of a bolt action and may not easily chamber cases larger than factory standards. Shooters who reload cases from one bolt action for another will also find it necessary to full length resize. Even shooters reloading for one bolt action will occasionally need to full length resize for the sake of easy clearance; over repeated firings the case may conform more and more tightly to chamber dimensions, making chambering and extraction increasingly difficult.

The combination of the Lee Collet Neck Sizer and Redding Body Die is an excellent way to neck size until they become too hard to chamber and then push the shoulder back .001" for partial full length resizing.

 

[Bart B.]

My comment:

I've seated 150-gr. bullets at different depths in .308 cases with their necks sized to the same dimension and got higher muzzle velocities with the deeper seated ones.

...was counter by Wood's comment:

This is clearly in conflict with Barnes data

There's no conflict with how I did the testing. I didn't change seating depth more than 50 to 60 thousandths. Note the first two bars for the .308 Win. with extruded powder which is in the range I did my tests. They show the deeper seated bullet has about 5,000 units more pressure. My tests had a higher velocity which follows this example pretty close as pressure had to be a bit higher. But yes, some cartridges sometimes show an decrease in pressure as seating depth increases. Note the .300 Win. Mag and RUM cartridges both have a pressure increase for the first 50 thousandths or so of increased bullet seating depth. It's probably dependent on several things.

Hornady's comment is much the same as what Nosler tells folks:

neck sizing alone usually promotes better accuracy, because when our reloaded cartridge is returned to the chamber it is almost a perfect fit; headspace is just right with all cases, whether rimmed, belted, or rimless; and most helpfully of all, the new bullet is almost perfectly aligned with the bore....

What they don't tell you is there's no significant difference in rimless bottleneck case's bullet alignment to the bore when the round's fired with both neck only and full length sized cases. Maybe both companies don't know this, but neither do most folks who reload. Neither one understands why Sierra Bullets' full length sizes their cases used to test bullets for accuracy and gets smaller groups than they do. There are reasons why Hornady and Nosler bullets are seldom seen in competition.

Hornady's comment on headspace for different cartridge types is misleading. Belted and rimmed cases' headspace isn't effected by firing and resizing them. These cases headspace at their back end where there's no dimensional change when any case resizing operation is made. Having talked with Hornady and Nosler about belted cases, they've both not believed that folks shooting belted cases winning matches and setting records got better accuracy with full length sized cases with body diameters reduced back to new case dimension in front of the belt, or using new cases, get better results than conventional full length or neck only sizing.

All this aside, people will reload ammo with tools and techniques they feel comfortable with. It's all limited by their skills and knowledge.

 

[youngda9]

For best accuracy when firing brass from the same gun. Use your full length sizer and back it off so that it only sizes 2/3 of the way down the neck of the case. This way the rest of the brass exactly fits your particular chamber. The bullet will be centered and pointing in the right direction since the rest of the cartridge is snug to your chamber.

 

[Bart B.]

youngda9 comments:

For best accuracy when firing brass from the same gun. Use your full length sizer and back it off so that it only sizes 2/3 of the way down the neck of the case. This way the rest of the brass exactly fits your particular chamber. The bullet will be centered and pointing in the right direction since the rest of the cartridge is snug to your chamber.

I tried this years ago. Sierra Bullets tried this back in the earlhy 1950's. The results were the same as others shooting high power competition while being classified as masters (those who typically win the matches and set the records). All the fired cases I've (we've) sized this way end up with greater case headspace than what the fired case had. Accuracy was not too good as the bolt bound up closing on the case with too much headspace and it didn't seat to the same place for each shot. The only place a case so sized will be snug is at the chamber shoulder and bolt face; its body is pressed against the chamber at the top of its back end and the bottom of its back end is a thousandths or more clear of the chamber bottom. Problems are amplified when the bolt face and case head are out of square, too.

However, if one full length sizes rimless bottleneck cases too much setting the fired case shoulder back too far, your process above (commonly called partial full length sizing) may produce better results.

Regardless of how a rimless bottleneck fired case is sized, the bullet will be well centered up front when it's fired because the firing pin's driven the case into the shoulder hard enough to set the shoulder back a few thousandths. The matching case and chamber shoulder angle makes this happen. At the back end, the case will be pressed against the top of the chamber by the extractor, but the slight angle the chamberd round has is insignificant to accuracy.

 

[essayons21]

I use lee collet neck sizers for my 30-06. I've also have RCBS full-length dies. Even when only slightly bumping the shoulder with the full-length dies, I get better results only neck sizing. I've loaded the same brass about 8 times now with no annealing or shoulder bumping and it still shoots fine.