The age-old neck size vs FL size question....

[Richcotte]

So, here goes....

For years, if I was using brass in only one rifle (.308 Win) once fired in that rifle, I always neck sized and had really great results, typically 1/2 MOA or better. Then, everyone kept telling me that I should always FL resize and go back to SAAMI specs to ensure consistent loads, so I did. I still got consistent 1/2 MOA or better from that rifle until it started loosening up from age and has settled in around 3/4 MOA.

I recently started loading Peterson Long brass for my 300 WM. If I use a FL resizing die per manufacturer's instructions, I will simply resize the long brass down to SAAMI specs and negate the benefit of the design. So, I fiddled with the depth and was able to resize and bump the shoulder back very close to the virgin Peterson Long that I measured for reference.

Now, the question I'm struggling with is that my chamber is obviously longer than even the Peterson Long specs, so should I just neck size and run with the brass fireformed to the chamber?

 

[Koda]

So, I fiddled with the depth and was able to resize and bump the shoulder back very close to the virgin Peterson Long that I measured for reference.

I think you answered your own question.

the purpose of shoulder bumping isnt to go back to saami spec, its to fit your chamber within a thou or two so you dont have to neck size.

 

[Richcotte]

@Koda what is the benefit of bumping back vs running with the fire formed dimensions? It seems to me that the less you rework the brass, the longer it should last.

 

[Koda]

@Koda what is the benefit of bumping back vs running with the fire formed dimensions? It seems to me that the less you rework the brass, the longer it should last.

the benefit is consistency because at some point you have to fully resize the neck sized case, but with shoulder bumping your "recipe" never changes. Im not certain how many firings neck sizers get before they have to resize again.
Your correct the less you work the brass the longer it lasts but with shoulder bumping your working the brass as minimal as possible, shoulder bumping should only move the shoulder no more than .002". Plus its best to anneal which I think is supposed to improve brass life, in my experience annealing made shoulder bumping more precise to control. Im not sure if neck sizers anneal between firings if not their case is getting work hardened each firing I think (someone correct me if Im wrong on that).

 

[Richcotte]

Makes perfect sense @Koda

Looks like I'll stick with the bump and just lock my die ring down for this brass...

 

[Muddyboots]

I neck size my Sendero 300WM and FL every 3rd which meant only twice to three times since brass failure of some sort at 9 loads normal.

BUT I also switched to Peterson Long and only 2-3 firing deep on any lot. So not sure when I will FL next. The Peterson Long is game changer going forward. I found that the Peterson Long is 0.002-0.003 setback from my chamber as new. Perfect! R-P, Win etc is 0.008-0.009 or more setback new so big stretch on new brass which is the brass killer from get go.

I just measure, test chambering to validate the brass will feed.

 

[Richcotte]

I neck size my Sendero 300WM and FL every 3rd which meant only twice to three times since brass failure of some sort at 9 loads normal.

BUT I also switched to Peterson Long and only 2-3 firing deep on any lot. So not sure when I will FL next. The Peterson Long is game changer going forward. I found that the Peterson Long is 0.002-0.003 setback from my chamber as new. Perfect! R-P, Win etc is 0.008-0.009 or more setback new so big stretch on new brass which is the brass killer from get go.

I just measure, test chambering to validate the brass will feed.

Agreed. Got a bunch of recently fired in the tumbler now and will measure when I pull them out to see just how much difference between them and virgin.

 

[BFD]

I neck size my Sendero 300WM and FL every 3rd which meant only twice to three times since brass failure of some sort at 9 loads normal.

BUT I also switched to Peterson Long and only 2-3 firing deep on any lot. So not sure when I will FL next. The Peterson Long is game changer going forward. I found that the Peterson Long is 0.002-0.003 setback from my chamber as new. Perfect! R-P, Win etc is 0.008-0.009 or more setback new so big stretch on new brass which is the brass killer from get go.

I just measure, test chambering to validate the brass will feed.

Daggum perfect! I will switch when I'm done with the 500 PPU cases I got before the global scam hit. They stretched .015 first firing.

 

[MeatBuck]

Full-Length Sizing for Reliable Precision

The question of whether or not to full-length size is one I get asked a lot. I always recommend full-length sizing the case, regardless of the rifle’s intended use. The benefits of reliability and …

panhandleprecision.com

 

[joe16]

the benefit is consistency because at some point you have to fully resize the neck sized case, but with shoulder bumping your "recipe" never changes. Im not certain how many firings neck sizers get before they have to resize again.
Your correct the less you work the brass the longer it lasts but with shoulder bumping your working the brass as minimal as possible, shoulder bumping should only move the shoulder no more than .002". Plus its best to anneal which I think is supposed to improve brass life, in my experience annealing made shoulder bumping more precise to control. Im not sure if neck sizers anneal between firings if not their case is getting work hardened each firing I think (someone correct me if Im wrong on that).

X2

 

[ButterBean]

I FL everything now

 

[joe16]

Hammer wise, I agree with Butterbean... A cartridge must cycle reliably and freely in a hunting rifle.

Play rifles (target) that I don't push hard, I agree with Koda 100% . I bump back. And even with the few rifles I load with the Lee collet die. The collet die cases get full length sized after five firings. 1, 8mm Mauser and 2 sav 308s. And the target cases won't get full length sized until 2 out of a batch won't chamber freely.

So I guess I straddle the fence on this one

I will add that I only use full length Sizer dies. (I prefer Lee dies) I do not use bushing dies. Just me, not saying anything wrong about bushing dies. I just started with these (FL) and had success. So I've stuck with them.

Joe

 

[Muddyboots]

Haha, my 300WM is the only rifle I neck size. I also verify feed on every round for hunting. It has to cycle perfect.

Guess I fibbed a little since everything else is FL.

 

[BountyHunter]

setting die sizing per instructions depends on what mftr. If you read reddings instructions, they start with sizing back to saami then later bring out sizing to just bump the shoulder back a couple thousands. remember die mftr instructions were written by lawyers and wanting to take back to sammi. That is not the best way for brass longevity and accuracy, bump 2-3 thousand