Home Forums Hunting & Shooting Ask The Gunwriters WSM's: Full length re-size or neck size only?

Hi all,

Was wondering if it's best to FL resize or neck size for WSM's? I'm want the best accuracy I can get from the rifle.

On Short Mags, they suggest only FL sizing and say that seems to work best. This seems to run contrary to my past experience with other calibers.

If FL sizing is better, what makes it better than neck sizing only for Short mags? can anybody explain?

Thanks,

JM

I don't know why but my 7 WSM M70 requires full length resizing to get it to feed easily, even with factory rounds. I wonder if it has to do with the higher pressures of the WSM loadings. I have not noticed the same thing with my .270 WSM, .325 WSM, or .243 WSSM. I played with it the other day trying to set the die to neck size but had to screw it down all the way before the bolt would close easily. I generally like neck sizing unless I am going to shoot the reloads in several different rifles.

I'm reading this like you wanted to neck size only with a FL die. With a cartridge having little taper to the body of the case the FL die is going to begin squeezing a good bit of the case body before you get much of the neck sized. This goes on well before forward movement of the shoulder is constrained by the die so the shoulder flows forward and voila, hard chambering. So you have to turn the die in until the shoulder is reset to a length that chambers nicely.

As to the widespread belief that neck sizing is always better for accuracy, well it ain't necessarily so.

Thanks for the replies fellas,

With a factory chamber, I don't know how much it can help accuracy. But neck sizing can save me on the brass.

I crudely calculated that I have .007 clearance in the chamber using factory ammo.

I was just wondering if anyone had experimented with FL and neck sizing in a WSM and seen any difference in accuracy or encountered any problems.

Notropis,

Attempting to neck-size with a full-length sizing die sometimes does not work well. This is particularly true with cartridges that have very little taper in the body. What happens is that the case body at the junction of the shoulder comes into contact with the sizing die well before the ram tops out. This actually "sizes" and reduces the diameter at the top of the body a bit, which has the side effect of lengthening the body just a bit. This partially-sized round is now actually too long to fit in the rifle's chamber. The only recourse, then, with the full-length sizing die is to go ahead and screw it down and full-length size the case. By the way, this is actually when the case neck stretches and gains in length - during the final stages of full-length sizing when the shoulder is shoved downward and the case brass extrudes forward into the neck.

If one wants to neck-size only, the best course is to obtain a neck-size die. This die is designed to not contact the case body or shoulder. However, neck-sizing can be done without spending the money for a new die if one is cleaver. As far as I know this is originally my idea as I have not heard or read of anyone else doing it, though I am not particularly well-read. The idea is to use a sizing die actually made for a different cartridge of the same bullet caliber, but with a larger diameter body. This way the case body does not contact the sizing die. The die must also be for a cartridge that is not so much longer than the cartridge to be sized so the neck can reach the neck portion inside the die. One example I can cite that I have used successfully is neck-sizing 7x57 cases in a 7-08 die. The 7-08 case body is larger in diameter at the shoulder than the 7x57 so only the neck of the 7x57 case contacts the die. Also, the 7-08 case is shorter than the 7x57, so there is no problem with the neck of the 7x57 case reaching the neck portion of the 7-08 sizing die. However, care must be taken to properly adjust the die so that only the neck of the case is sized when the ram of the press is fully raised. My 7-08 die had to be backed-off considerably for this purpose so as not to transform my precious 7x57 brass into 7-08s with a bad headstamp.

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Mathman, The just-fired cases would not fit easily back into the chamber even before I started tinkering with the resizing die. I don't understand why because they ejected easily. Sizing them with the dies backed out a bit did make them a little harder to chamber.

Perhaps neck sizing is not really what I do most of the time. I usually try not to bump the shoulder back so far that it has to stretch a lot when the round is fired, especially with belted cases.

Notropis, try making the marking and try chambering it and then turning the case 20-30 degrees and retry. Several WSM's that I've seen/heard of have chambers that are out of round - had one myself and when I got the orientation of the case right, it would chamber easily - otherwise it was hard to chamber.

I use a Redding bushing neck die to resize for my 270WSM (different rifle than mentioned above) - after 4 firings so far on my brass, I have yet to need to FLS.

If a fired case will not chamber in the same rifle it was fired in, it is possible that the chamber in that rifle is deformed in some way. If the case is indexed to the same orientation as when it was fired, it might chamber.

Edited to add: Yes, out-of-round are the correct words. TXRam beat me the the "Submit" button.

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That's what I do, I set the FL sizer die down just enough to allow for proper chambering. I do not want to move the shoulder much at all.

An out of round chamber is a possibility when fired brass won't go back in.

Is an out of round chamber common or is it an anomoly?

I've read about issues some people had with WSM chambers being o-o-r in rifles with smaller diameter barrel tenons. The chamber may have been cut true but got torqued out of shape when tightened (overtightened?) into the action.

I don't really know how common it is.

You cannot neck size with a FL die. You can either FL or PFL size. In a FL die, the body of the case makes contact with the die before the neck is near the sizing area. You can easily prove that by trying to insert a case into the FL die by hand. Mark on the side of the case how far it goes into the FL die. Withdraw the case and lay it beside the die, note how much farther the case would have to go into the die before it starts sizing the neck. I neck size my 300WSM cases with a bushing die and normally get 4-5 loads per case before I have to PFL. Also I don't set my FL die to PFL until the cases start to get snug in the chamber.Rick.

I'm not sure why you're telling me this. In my early post I outlined the trouble that arises when it's attempted. In my later post I mentioned turning down the FL die to achieve proper chambering, i.e. size the body, shoulder and neck just barely enough.

I'd say he was just using the quick reply.

The M70 SS Classic I have in 7mm WSM has an out of round chamber. I am keeping the rifle as its very accurate.

Otherwise I have a number of pre-64 M70's and other interesting rifles. I am reluctant to buy another post 64 M70.

Maybe so. It's no big deal, just trying to be clear.

..............John........I full size all my 300 WSM cases. At first, when I first began reloading for this cartridge, my shellholder was barely touching the bottom of the RCBS FL die. As a result, the case shoulders were hanging up during feeding from the magazine to the chamber.

I screwed my die down (clockwise) another 1/4 turn, which immediately solved the problem. Apparently, the casing shoulders weren`t being sized down quite enough. I`ve had nothing but flawless feeding since.

That`s not to say that in some 300 WSM rifles partial sizing or neck sizing cannot be done effectively. However, in my particular rifle, neck sizing or partial sizing won`t work unless I load one round at a time. Good for range loads, but not the best for hunting when magazine loadings should be used. The 300 WSM as a stout 35 degree shoulder angle, which imo, requires me to full size the casings for hunting loads.

As to which is better for accuracy? FL or neck sizing? Depends on your rifle and where you are, either hunting or at the range.

mathman, the reply was not directed to you but to the general conversation. You just happened to be one post in front of mine. The neck size with a FL die comes up with regularity and I usually post about what I said today.Rick.

I think it's probably pretty common to an extent, but to the extent where brass won't chamber is an anomoly.

In-line dies resize the neck only and don't work the case much, and it would seem that if you've got a severely out-of-round chamber, they wouldn't work, but the seem to work fine in every instance I'm familiar with. I've never had a round that wouldn't rechamber in the same rifle, so I don't know exactly what that denotes.

It depends...for any round that I intend to hunt big game with I full length resize as I put function and reliability first and foremost...

These days I always full length resize as I may not have that same rifle the next time I want to shoot that caliber, and I want my ammo to work in ANY rifle..

I will give up that perhaps or at least sometimes fictional improved quarter of a minute accuracy that is claimed with neck sizing for the benitfits of full length resized ammo. I tend to put little importance in where I seat the bullet in the case, so another holy grail bites the dust, but low and behold, My guns still shoot under an inch or I sell them.

I have seen way too many failures with tight fitting cases...For targets?, sure if you so inclined, do it. For varmints?, sure, if you wish but then who cares if you have to clear a jam or can't chamber a round and miss an opertunity on a rockchuck or rabbit, that is not a life threatening moment IMO, and if if neck sizing makes you all warm and fuzzy, then get after it.

But, as you get older and deal with these myths and parables, you tend to put your give a sh--ter in neutral and don't do things as meticulasly as you used to...Thank goodness! You also tend to toss grammer and spelling to the four winds and hope for communications with the masses and ignore the professors!