neck sizing vs. full length sizing - bolt guns

[45Badger]

I've been using Lee 3 die sets (deprime/size, seat, crimp) for all my rifle caliber reloading, and have been quite happy with the results. I've mostly been reloading for used for semi auto rifles, but have recently picked up a couple nice bolt guns in .223 and .308 win.

I'm keeping the brass used in these guns separate from the bulk piles. Is there any significant advantage to be gained by using a neck sizing die vs. a FL sizing die? If so, please explain. Also, please recommend a brand/model.


Thanks!

 

[dakotasin]

you can take a fl die and just back it off and get similiar results.

a true neck size die will stay off the shoulder. your fireformed cases will then be an exact fit to your chamber. assuming concentric ammo and good barrel/chamber quality, this results in a bullet that starts out straight when entering the barrel - no yaw. end result is increased accuracy.

you'll have to experiment w/ your rifles yourself to see if you can produce handloaded ammo that is up to that level of precision and if your rifles are accurate enough to realize it.

you're about to embark on the 1-hole group odyssey. welcome aboard, good luck keeping your sanity (i don't have much left)...

 

[243winxb]

Is there any significant advantage to be gained by using a neck sizing die vs. a FL sizing die?

You don't have to wipe the lube off the body of the case when neck sizing.

 

[CZ223]

Badger

What Dakota said is right. Using a neck sizer or backing off your full length resizer die also works the case less and therefore prolongs case life. I have been using the method Dakota recomended for years with great success using standard factory dies by Hornady, Redding and RCBS. The only drawback to either of these methods is that your bolt may close harder, even when using brass that is formed in your rifles chamber. This is the reason that a lot guys, the 6BR types, are using neck dies with a shoulder bump that moves the shoulder back a couple of thousandths. Unless you are hunting or getting into serious competition it shouldn't bother you.

 

[Redneck with a 40]

I neck size in my Remington 700 SPS, I've had very good luck with it, the only brass that gives me problems is Prvi, even after its fired in my rifle, I still have to full length size. Remington, Federal, Winchester, all neck size just fine. I'm using an RCBS die, which sizes them down enough to fit my very tight chamber, the Lee die won't. I have one, tried it, no dice.

 

[kelbro]

I have some rifles that shoot better with neck-sized brass and some that prefer full length sized. You just have to experiment.

 

[Bart B.]

If one finds out what folks shooting high power rifle matches have used to win and set records along the way, they'll learn that proper full length sized cases shoot bullets the most accurate. Mid & Nancy Tompkins and thier daughters Michelle and Sherri Gallagher as well as David Tubb and many others have been full length sizing forever.

Sierra Bullets tests their products from full length sized cases and their best ones easily go into groups benchresters would envy. Full length sized cases have been used to shoot smaller groups than those setting benchrest records at 600 and 1000 yards with neck sized cases.

Case life for the .308 Win. can easily be more than 50 (sometimes as many as 90) reloads per case without any annealing whatsoever if done correctly. Use a full length sizing die with its neck lapped out to 2 or 3 thousandths of an inch smaller than a loaded round's neck diameter so no neck-bending expander ball is used then set the die such that it sets the fired case shoulder back no more than 2 thousandths. You can use an unmodified full length sizing die with an expander ball but case life will be cut in half.

The old myth that neck only sized cases fit the chamber perfectly is easily busted. First off, cases and chambers are not perfectly round. Measure them with proper tools and you'll see they are a bit oval shaped; cases more so than chambers. Second, every rimless bottleneck case has its shoulder set back a few to several thousandths of an inch by firing pin impact driving it forward before it fires so there's always some clearance between the case head and bolt face when the powder burns and pressure builds up. This centers the case shoulder in the chamber and if the case neck is centered on its shoulder, it also is well centered in the chamber neck. As pressure peaks, it stretches the case body back so the head stops against the bolt face. Third, the back of the case is held off center to the side with claw extractors and up with bolt face extractors from the chamber center by the extractor pushing it there when the bolt's closed. It stays there when the round's fired but may move some direction when the firing pin hits it.

 

[something vague]

But there would be far less stretching with a case that is just neck sized, therefore prolonging the cases life by almost double. I do agree that neck sized only brass will probably not be as accurate as F/L sized brass and for the most part have experienced this in almost all cases. But it is usually by an extremely small amount, and the advantage of longer case life is more advantagous than the tiny increase in accuracy for me.

You have to realize that fire formed brass would need to be inserted in the chamber the exact way it was fired in order to have everything lined up. Like some people have said, chambers are not perfectly round. But I do believe in neck sizing in order to prolong my case life.

 

[Redneck with a 40]

I'm getting 1" groups at 200 yards in my .308 with neck sized brass, thats .5 MOA, plenty good enough for me.

 

[loadedround]

Big factor to consider also in neck sizing only is case life. Less working of the brass means more reloads.

 

[Bart B.]

something vague comments:

But there would be far less stretching with a case that is just neck sized, therefore prolonging the cases life by almost double.

I used to think this was normal. Then I measured shoulder setback firing empty primed .308 Win. cases in several rifles chambered for them. Neck only sized and fired reprimed cases had their shoulders set back the same amount as full length sized cases with shoulders set back a couple thousandths when sized. Shoulder setback caused by firing pin impact was about 8 to 10 thousandths of an inch with all of them.

Every rimless bottleneck fired case I've measured has always been shorter than before it was fired. It's the sizing process that makes them longer. How much is determined by the dimensions of the fired case and sizing die.

 

[ranger335v]

Seating/crimping in one step or two; doing it seperately is most commonly the better way to go. Getting consistant OAL demands we push the press lever to it's full limit each time and that may not attain a consistant crimp.

Consistant crimping with a standard seater/crimper die demands the cases be exactly the same length. If not, crimping variatiaons WILL occur. If we set the crimp ring at mid-point, a short case may not get a crimp at all while a long case may actually crimp-crumple the case shoulder when getting the bullet fully seated.

Lee's excellant Factory Crimp Die is not nearly so length dependant. Lee's collet crimping design for rifles works on an entirely different principle which renders modest case length variations irrelevant. That removes a lot of reloading "grunt work" just to keep cases trimmed equally for each loading session.

 

[Bart B.]

Redneck with a 40 says:

I'm getting 1" groups at 200 yards in my .308 with neck sized brass, thats .5 MOA, plenty good enough for me.

Is that the smallest groups you get or are they all that size or smaller?

Accuracy anyone can count on all the time is at least what the largest group is.

 

[Redneck with a 40]

No, my largest groups at 200 yards are 2", that's still MOA, which I'm perfectly happy with. I'm also using a Lee Collet neck sizing die, which I really like. I can load my cases 5 times before I have to trim them, plus I stay away from max charges. Case trimming is a major PIA to me, so avoiding it is nice.

 

[jpwilly]

^ Why is trimming so difficult? If you have a cordless hand drill get yourself the Lee trimmer and cutter set. Chuck up the cutter, Set the trimmer and have at it. I can trim hundreds of resized cases pretty quickly that way. And it cost around $10 for the set up.

 

[something vague]

I like the idea of the Lee trimmer set up as it can be used in a bunch of different ways. The problem I have is that you are pretty much stuck with a set length that you have to trim at, which in my opinion is far too short for my liking. I don't like going all the way down to the trim to length that is listed in the manuals as I have found the longer the neck, the better my loads shoot. Might have to do with neck tension but I can't say for sure. I suppose you could unscrew the pilot on the Lee cutter but then you risk it moving around to different lengths. I like the old Lyman trimmer myself, but this is just what I'm used to. To each his own though, and there is def. great advantages to many other methods of trimming cases. BTW, I don't mind trimming cases either.

 

[armoredman]

I neck size my 303 brit, only way to get more than 3 loads out of it! Lee neck sizing die, works great.

 

[Redneck with a 40]

I guess my technique is crap, because with my lee cutter/lock-stud chucked in a drill, I'll spend 30 minutes trimming 20 cases. The lee neck sizing die saves me from this headache.

Is it ok to have cases that are longer than the 2.015 spec? My lee cutter will trim them down to 2.005. I know that headspace in .308 is important, if the neck is too long, it'll pinch the neck in the chamber upon firing, pressure skyrockets, which equals a bad day.

 

[something vague]

Redneck,

Have you noticed with your factory mandrel on your Lee Collet Die that your neck tension ends up very loose compared to a F/L die? Seating a bullet after using the Lee Collet is almost too easy. That is my experience with Lee Collet in .223 and was wondering if you or anyone else has the same issue. I'm getting around .001" neck tension. Do you think that is too loose?

 

[Doug b]

Something vague that has been my experience with Lee's collet dies also.Recently started loading .22 hornet with a collet ,the mandrel measured .224" as in no neck tension at all.I chucked it in a drill and polished it down to .221" to get adequite tension on all cases.

A real pain but I like the results I'm getting using this neck size method with the dead length seater.

 

[Bart B.]

Redneck with a 40 comments:

I can load my cases 5 times before I have to trim them, plus I stay away from max charges.

Some years ago, I took a new Federal .308 Win. case, sized its neck to just hold a bullet, then trimmed it to an even 2.000 inches. Loaded a max charge of metered IMR4895 atop a Federal 210 primer then seated a 165-gr. spitzer hunting bullet. A friend at the bench of his underground 100-yard range shot that round in a standard SAAMI dimensioned chamber and the fired case was about .004 inch shorter. I full length sized the case which lengthened it to 2.001-in, primed, charged and seated another bullet to shoot.

We repeated this for 47 loads on that case before running out of test powder. Each time the case was fired it shortened a few thousandths. When full length sized, it grew about a thousandths more than it shortened when fired. When it got to 2.010 inch, I trimmed it back to an even 2.000 inches. That case was trimmed back 4 times during this session with a single case.

Muzzle velocity spread was 22 fps across all 47 shots that he shot into a cluster about 3/4ths of an inch. Evidence that neck tension remained very uniform across all loads. No annealing was done as none was needed. We could have gone another 20 to 30 loads on that same case but our schedules didn't allow it. My friend was quite surprised that a single case could be reloaded that many times with maximum loads and full length sized each time, too. We credited much of the case life to the die's neck being lapped out to about .003-inch smaller than loaded round neck diameter. No expander ball was used and fired cases were deprimed with a separate decapping die.

 

[Poper]

Have you noticed with your factory mandrel on your Lee Collet Die that your neck tension ends up very loose compared to a F/L die? Seating a bullet after using the Lee Collet is almost too easy. That is my experience with Lee Collet in .223 and was wondering if you or anyone else has the same issue.

I too, had this issue with a .222 Rem. Collet die. I chucked the mandrel into my drill press and polished its diameter down .001" with emery cloth. Fixed the issue nicely for me.

Poper

 

[Poper]

We credited much of the case life to the die's neck being lapped out to about .003-inch smaller than loaded round neck diameter. No expander ball was used and fired cases were deprimed with a separate decapping die.

Interesting. Does this mean you outside neck turn or inside neck ream all of your brass to get uniform neck wall thickness and thus uniform tension on the bullet? If so, what is the min/max neck wall thickness you find acceptable?

Poper

 

[Redneck with a 40]

I actually encounter light resistance when I'm seating my bullets, with the Lee collet die. My reloads are shooting great, about 50% of my groups are sub-moa, so I think I'm doing fine.

 

[something vague]

I just shot 20 of my reloads today that I neck sized with the Lee Collet die which only produced about .001" of neck tension (inside diameter before seated bullet was .2225"-.223"). I went through and shot 5 shot groups with these 20 rounds and waited a good 15mins in between groups to let the barrel cool down. All shots were at 100yrds and shot through a Ruger M77 mark II .223 rem.

Needless to say, I was extremely happy with the accuracy of these reloads. My largest group was .87" while my smallest group was a mere .32". The largest group was actually closer to the smallest with 4 of the shots but I ended up with a flyer that I could feel while shooting it (my error). Who says that a Ruger M77 can't shoot? I have been nothing but blown away by this rifle as I was expecting mediocre results after hearing what has been said about them.

Anyways, my point is that .001" of neck tension ended up creating a very accurate load. I did not expect these results what so ever and am glad that I didn't polish down my mandrel for more neck tension. I ordered another one from Lee and will polish that one down to compare the results.