Clem Bronkoski
Well-Known Member
I FL size only and my rifle shoots .5 MOA or better groups all day
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Full length sizing VS neck sizing
- Thread starter sniperjwt
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Mikecr
Well-Known Member
And there are people neck sizing only and shooting 1/2moa or better.
What's the point? That FL sizing is required to shoot well?
No,,
What's the point? That FL sizing is required to shoot well?
No,,
No. Staying away from the shoulder is his goal I believe.
some rifle need help some don't
Mikecr
Well-Known Member
I've never seen that happen. Necks spring back to clear chamber neck without leaving any interference.
The reason I surmise relates to pressure applied to area and neck thickness per that area.
A 60Kpsi pressure produces less force against neck area -vs- case body area. There is more barrel steel around chamber necks, so chamber neck expands less. The relative thickness of necks for area is high, so necks have no problem springing back to clear.
You can run out of clearance at the neck-shoulder junction from donut brass thickness -if seating bullet bearing deep enough to push it out. But sizing won't fix that. You can run out of rechambering clearance if necks are over annealed, but that alone won't stop you from rechambering, nor hurt anything at all.
The biggest issue I have with FL sizing of necks is that it creates huge neck tension variances.
If bullet bearing is not seated fully through necks but you FL sized the neck, then you leave a non expanded portion of neck to bind against bullet bearing-base junction. This will raise SD, mess with tune, and unless neck friction is very high, CBTO will change over time (similar as with compressed loads). FL sizing of necks also brings donut brass thickness into tension, and that brass thickness is less controlled/less consistent. Fl sizing of necks raises neck tension considerably (excessively), and higher of anything means higher variance of it. FL sizing of necks raises runout, and finally, by FL sizing of necks you give up a valuable adjustment to neck tension (sizing length).
The only occasion where FL sizing of necks could benefit is with small underbore cartridges (competitive) that need very high starting pressure to reach extreme peak pressure levels. In this case nobody cares about the variance in tension, they just need it high enough.
That is a special situation that does not apply to hunting capacity cartridges, which really are viably limited to SAAMI max pressures..
QuietTexan
Well-Known Member
Any die will size the neck to an extent, a bushing die has a hole for the neck to go through even without a bushing installed.
What I was getting at was if there was a portion of the neck not sized would it react like a neck sized case in that after several firings the case begins to have difficulty chambering and a full length sizing is necessary. Mike posted he never seen this happen.
Clem Bronkoski
Well-Known Member
I guess its like 30-06 said. It all depends on the rifle. Would my accuracy improve if I were to neck size only? Possibly. But how about reliable chambering? I use my rifle to hunt also and should I need a quick follow up shot I don't want to have to mess around with a "sticky" round that's difficult to chamber.
If you test fit your ammo that is never an issue. Even fl sizing doesn't guarantee a perfect fit. I personally even test fit factory ammo, I have had a couple of boxes that don't feed well that i needed to replace.
Mikecr
Well-Known Member
There is fleeting accuracy from cases that don't last very long in a stable/as load developed condition.
And there is longer term accuracy from cases that last many more reload cycles in a stable/as load developed condition.
Whether you even have this choice comes down to your understanding & planning.
Regardless of sizing, if your cases turn out to be unreliable in the field, then your planning needs work for sure.
If you ever thought you might neck size only and ended up disappointed, then your understanding needs work.
The comparison really should never have been NS-vs-FL.
I know of no cartridges that can go forever without shoulder bumping(eventually). That at least limits NS ONLY viability.
The better comparison is minimal sizing -vs- off-the-shelf FL sizing.
I say 'off-the-shelf' because you can choose to have custom FL dies that minimally size, and cases should last way longer(as stable), then accuracy from those cases should last longer. It's logical and reasonable to follow that and other plans for minimal sizing.
How that line of thinking was lumped into neck sizing (only) is beyond my understanding.
Clem Bronkoski
Well-Known Member
That my friend is a very logical post. thanks.
Thank you for this post. I suppose I have seen too many YouTube videos which have got me questioning some basic premises on full length resizing. First and foremost can I use a standard full length die ( Lee Precision, for example) to bump the shoulder back .001" or .002", and exactly what is happening to the neck dimension during full length sizing??
I stopped neck sizing long ago before Erik came out with this video.
That is pretty funny ... not telling you what to do ..... but you are an idiot if you do anything else than others do that are addicted to the sport and spend tens of thousands of dollars searching for a competitive advantage. I am not saying what they do doesn't work.
IF you are new to reloading and you will never reload the brass more than 2 or 3 times you might see an improvement by neck sizing only. I am not saying you cant neck size only more than that, but it seems like that is a safe bet. IF you have the knowledge and equipment to consistently resize brass then you can probably avoid the cons of neck sizing only and maintain or exceed any accuracy improvement. You do need some equipment and some skills that you may or may not have. You will not magically get better results because you FL resize.
I neck sized only on a 300WM for a M77 for 20years that was used exclusively for hunting. The neck sized only did seem to shoot slightly better that what I could extract with FL sizing (using non bushing die) with the equipment I had. Today, I body size with a bushing and bump the shoulder back 0.002. I get roughly the same results with more steps, but I feel a little more confident that a round will chamber smoothly in a hunting situation. On the other hand, the only rounds that have chambered hard in the field were with rifles that were running FL resized ammo. I am not entirely sure a pine needle or a chunk of bark fits that much better with the extra clearance.
In my opinion, give it a try and judge for yourself. As mentioned by others, cycle your ammo to make sure it cycles smoothly. Personally, I would neck size if I wasn't willing to step up to a bushing die that allows me to partially resize the neck. I think leaving part of the neck as fired gets things lined up better.
