Why FL resize?

[K22]

This is a myth from the 60's that neck sizing will promotes better accuracy and longer case life. Neither is true IF you learn how to full size properly which is not difficult at all. This means using a bump gauge and a caliper to set your F/L die for an optimum size, dedicating a group of cases to a specific rifle and rotating their use.

I am speaking from real world experience of almost 60 years of reloading for precision. Like many of my generation, I believed this myth. I neck sized for years and could never predict when I would encounter a difficult reload to chamber without the tedious process of checking every reload before I went afield. In addition, I increase the wear of the bolt lugs from eventually hard chambering, galling the lugs.

As primarily a hunter, albeit precision hunter for varmints and predators, I can assure you that F/L sizing is the only way to go. Post #6 is spot on - reliability. In addition, you give up nothing F/L in the case life and the accuracy departments. I know, I have done both and I can positively attest to this fact.

But as Hondo Lane once said, man has to do what he feels is best. So, if you want to continue to neck size - go for it.

 

[charlie b]

My experience with neck vs FL is limited. I was also 'taught' that neck sizing was good for accuracy (back in the 70's). I did find later that when pushing brass hard it needs to be FL sized every 4 or 5 reloads (it starts sticking in the chamber). I am not good enough at shooting to see any difference in accuracy between the two. These days I use FL dies.

The reason I did neck sizing a lot was for cast bullet loads. Reduced pressures meant I could neck size for many reload cycles (as many as 40 per case). Neck sizing with the Lee die meant good neck concentricity and simpler process.

 

[Webster]

Sage advice all. I FL all my rifle brass.
Listen and learn is what Tony Boyer told me at the Super Shoot. He won everything that year.

I think Tony had 172 HOF points. Believe what he says.

 

[Medic505]

Or, just for grins and to complicate things a little more, you can size your brass with a body die and size the neck separately with a bushing die or a Lee collet die. Lee will make a mandrel to whatever size you want if you are experimenting with neck tension. This is the method I used for match ammo.

 

[Rob01]

I like my brass prep simpler than more complicated and use a FL bushing die to do the same thing in one step.

 

[kenhwind]

Kinda a must for any semi-auto.

And lever actions

 

[ELR LVR]

I like my brass prep simpler than more complicated and use a FL bushing die to do the same thing in one step.

I think this is the best method

 

[Doom]

My experience with neck vs FL is limited. I was also 'taught' that neck sizing was good for accuracy (back in the 70's). I did find later that when pushing brass hard it needs to be FL sized every 4 or 5 reloads (it starts sticking in the chamber). I am not good enough at shooting to see any difference in accuracy between the two. These days I use FL dies.

The reason I did neck sizing a lot was for cast bullet loads. Reduced pressures meant I could neck size for many reload cycles (as many as 40 per case). Neck sizing with the Lee die meant good neck concentricity and simpler process.

OK, I'll throw may experience in the ring. I have neck sized 308 and 223 brass in in bolt guns for 15 years for shooting off the bench (not competitively). I shoot moderate loads in the 308 with the 168 SMK and 43 gn of IMR4064. I have not had to resize that brass for chambering issues. The 223 is shot with 52/53 gn match bullets and between 25 and 26 gn of 8208XBR and have had the same experience.

I have been running some tests with bumping the shoulder back with the FLS die on both and here is what I have found. Both rifles are factory barrel Remington 700's (2009 and 2011 vintage).

1) Accuracy-The jury is still out. Any change in POI appears to be in the noise.
2) Precision-Anecdotal evidence seems to show that neck sizing MAY have a tendency to have more "flyers".
3) Because the chambers have body diameter dimensions larger than the resizing die the bumped brass grows In overall length on every firing/resizing cycle. In both cases it's about four to five thousandths.
4) The higher the pressure of the load is the greater the likelyhood that the case may be hard to chamber or not chamber.
5) Using OCW the charge weights don't change enough to affect the node.

For the record the 223 cases were Lapua and for the most part the 308 cases were Lake City and mostly LC 05. The 223 is capable of sub 1/2 MOA groups (10 shots). The 308 is capable of 1/2 MOA groups (5 shot).

My recommendation: Try it for yourself, but if I had a custom rifle with tighter chambers and was looking for F-Class accuracy I would FLS bumping the shoulder.

 

[Leo_B]

Based on, so far, two dozen excellent responses it is perfectly clear the answer is 100% clear you should only neck size brass, except for being 100% clear you should only FL size brass. I appreciate all the responses and look forward to (m)any more. Definitely going to be some more serious studying and spec'ing to do on this one.

 

[Rob01]

Based on, so far, two dozen excellent responses it is perfectly clear the answer is 100% clear you should only neck size brass, except for being 100% clear you should only FL size brass. I appreciate all the responses and look forward to (m)any more. Definitely going to be some more serious studying and spec'ing to do on this one.

No studying needed unless you just like making your life harder. Get a FL bushing die. That simple.

 

[Leo_B]

No studying needed unless you just like making your life harder. Get a FL bushing die. That simple.

Not harder, interesting. I find it interesting reading and researching stuff like this. And I learn along the way.

 

[Rob01]

Not harder, interesting. I find it interesting reading and researching stuff like this. And I learn along the way.

Your time. lol Trying to help you not waste it but have at it. Just don’t get into analysis paralysis.

 

[Leo_B]

Reading and learning are never a waste of time, mine anyway.

 

[47WillysGuy]

To many other facets of precision shooting for me to worry about whether full sizing or neck sizing is better.
But I DO what I feel is best for my reloading and so should you. That’s the way you learn. Good luck!

 

[Doom]

In an ideal word the best solution would be to a FLS die made from your fired case so that the resized case would be only minimally smaller than the chamber. Regular, bushing, or whatever.

 

[dellet]

@Leo_B

Nothing wrong with neck only sizing, as long as you understand the limitations, and/or have a reason to do so. Understand the time in history it was popular and consider the advances in machining tolerances since then.

Testing the accuracy and repeatability of neck sizing is very, very simple.
First you need a rifle and load that will shoot one hole at a given distance. It doesn’t really matter how far, but a true one hole.

The argument against neck only sizing is twofold. Eventful hard to chamber. Accuracy loss due to miss match of fired brass shape to imperfect chamber shape. Both of those are pretty easy to over come. First shoot mild loads, you will still need to resize the body at some point, but it doesn’t need to be every firing. Case shape will also be a factor.

Accuracy is simple to test, no one takes the time.
Shoot at a distance where your group opens up some. Number of shots in the group doesn’t matter much, but as always the more shots. The more likely to see a difference. The distance and number of shots needs to be enough that you trust the results.

Shoot a five shot group with all five rounds. Then shoot five, five shot groups with each piece of brass. If neck sizing is a problem, you will have five groups that that measure the same as the original five shot group shot with all cases. What you should see tho is five different groups impacting slightly different off the point of aim

To refine that, index the brass so that it is in the chamber exactly the same way every shot. Then index the die so the neck is formed the same place every time.

The argument concerning accuracy is random placement of a fired piece of brass that is out of round. Simple fix is remove the random.

If there truly is a problem neck only sizing, you should be able to take a full length sized case that can be reloaded on the bench and shoot a single hole with at least four shots. Then neck size the same piece of brass and index the case at 3, 6, 9, 12 and shoot a box similar to a scope tracking test.

If you look at the history of shooting you will see many ways of improving the repeatability of shot to shot placement. It runs in circles. Eliminate a variable, bullet run out, by manually correcting after seating. Everyone buys a tool for that. Tighten the tolerances in sizing and seating dies, everyone stops using the tools and eventually people start getting laughed at for checking neck and bullet concentricity.

Try it for yourself, worst thing that happens is you learn something. You might even find you have two different answers for two different cartridges. 22 Hornet vs 223. That actually is a huge problem in hand loading. There are no real universal answers.