One thing that should be understood about partial FL sizing, aka bumping the shoulder with a FL die, is that the shoulder will actually flow forward to some extent before it gets pushed back. It might vary depending on the taper of the case and the size of the chamber, but it does happen.

I should add that a body die can do the same thing.

As I said, I haven't had a stuck, fired case via neck sizing only over the past 4-5 yrs, which is the time I started NS only. It still perplexes me how a fireformed, one rifle only case, can stick in the chamber of it's specific rifle after firing it. Given the fact you're not redlining your ammo of course.

So whereas with a fl die I am used to setting it for cam over and running down the entire brass.


To bump the neck I am just hitting the shoulder and not necessarily getting cam over

Is that fair?

Sounds right to me.

I don't know about sticking cases in the chamber, but I notice bolt closure getting tight after several firings when using neck sizing only. I'm loading about a dozen different cartridges though and may have failed to note that some are more prone than others. I probably should keep better records.

I agree with it getting slightly "tight". That's a good indication to me of a fully fireformed case conforming to my chamber. Less stretch, they last longer, at least in my feeble mind.

I had a few .308 Lapua brass out of a batch of 50 come out a little snug when closing the bolt which was annealed and full sized. What would you think the issue may be? Spring back because it was not perfectly annealed? I bumped back .002" as well. I was using 650 Tempilaq back then and started annealing for the first time and maybe it was not 100% cured, so I switched to 700 degree Tempilaq. I have not seen it do it much anymore, started annealing every firing now. What is your opinion?

My opinion? It may well have been as you think. Full annealing takes place very quickly at 750, and if it didn't reach that temperature, then maybe that's exactly what happened. I always anneal before any resizing, BTW.

Yes, I decap and anneal, tumble and resize.

It was once explained to me that no matter how truly concentric we believe the chambers of our guns to be, there may be slight variations. The chances of putting the brass in the chamber in the exact orientation it was fireformed in is unrealistic, and therefore might be a cause of a sticky chamber. Just something to consider...

When you guys mention that bolt drop starts to get a little tight on closure, that is your sign that your shoulders need to be pushed back. I can promise you-from personal experience-that the rounds that the bolt closes "tight" on WILL IN FACT shoot to a different point of impact than a properly sized cartridge that closes with no bolt resistance.

When they get that tight, it's time to bump the shoulder back at least .002", and then also trim to length, or at least measure the length as that case is telling you that the brass is flowing forward. You can test this theory. Find some brass that closes tightly in your chamber. Now reload it by neck sizing only. Now F/L resize and load 3 more rounds using the same bullet, powder, and charge weight. Now go and shoot those rounds. You will see that the "tight" brass will shoot on the paper away from the others. The farther out you can shoot, the more obvious this will be. It may be only a slight difference at 100 yards, but try shooting at 300 and the margin will be large enough to be easily evident. So, unless ALL of your brass has the exact same "crush-fit" in your chamber-which is not likely, then your accuracy will be affected by those rounds that have bolt closure resistance. This has been my experience. Yours may vary.