Am i Neck turning enough?

[TheSilverFox]

Question #1

I have a no turn neck chamber in .308 Winchester. Yu can see in the pic that I could obviously take more off, but should I?

Depending on the brass i take up to .003".On extreme cases, down From .341" to .338" O.D. The non trimmed parts you can see are sometimes around .337" but no more.

Here's the stats,

chamber OD is .343"
neck turn up to .003" off
Neck bushing is .336"
neck OD once bullet is inserted is .3375"

Question #2

If your fireformed brass has an OAL diffenrence of .003",For 100 Pieces)at the most. Would you tim it again?

 

[billmo]

Silver Fox, I would not take any more off. If you take much more off you might have to drop dowm with your neck bushing size in order to get adequate neck tension. I would not trim 100 cases for .003 Bill

 

[mikecr]

At risk of seeming like I'm trolling, what do the neck ODs measure after firing, when you pull em out of the chamber?
Just curious

 

[TheSilverFox]

0.343"

 

[Travelor]

With that size chamber neck, I would not turn at all. Your describing the loaded rounds to be .0055 smaller thant the chamber and it wold be much better at .002 to .003 max.

 

[ReedG]

You are caught in the "factory chamber" syndrome. The purposes for neck turning are to get the proper clearance for a custom chamber, or to skim trim enough to get the necks to all one size. In the case of a chamber like yours,and most others) it is a lost cause. If you take off enough to get even neck thicknesses, the overall diameter is so small that you have size down a lot to get good neck tension; then the brass expands out to the "loose" factory neck and causes extreme working of the brass.

In your situation, I would cease-and-desist on the neck turning and go with trimming to length to get a nice square neck to work with. With necks measuring .3375 with bullets seated, and a bullet of probably .3085, your necks are about .0145 or so. With a .343 neck you want all the neck thickness you can get.

In my opinion, this is a situation where Collet Neck Sizing dies really shine. With a bushing neck sizer, any inconsistencies in the brass are pushed to the inside of the neck. With turned necks for custom chambers this isn't a problem. With factory brass it is. The Collet Neck Size die forms the neck to a mandrel on the inside, making the inside consistent regardless of the neck thickness and all imperfections on the outside. I am a real believer in the Lee Collet dies and another benefit is no lube is used.

Bushing dies are great for custom chambers and turned necks, but the Collet Neck dies are better on factory brass, in my experience.

 

[TheSilverFox]

Thanks guys, i'll do that. I'm glad i only turned the three cases, not the wole lot. lol. The thing is, i can really see the benefits in turning. I'll look into it for my next barrel

Merry Christmas

 

[Klong]

You should load the turned cases with your favorite load and see if they shoot any better. If not I would not turn any more of them. Many people turn cases as you did just to be sure the case necks are uniform. Ken

 

[TheSilverFox]

Well i was thinking about it?

At .338" bushing without neck turning, the bullets are way too loose, I dont think they are safe.

At .337" the tension feels correct.

The thing is that these necks are tapered from top to shoulder. Top usually being pretty good and section close to shoulder about .003 thicker. When i trim i make the whole neck consistent so i can resize at .336"

Should i just leave it alone, or trim just a "hair"
and see if it improved accuracy?

 

[billmo]

I believe once those new cases are fired they would lose the taper. I don't see you gaining anything by turning those necks for that rifle. Just my opinion. Bill

 

[TheSilverFox]

Ok guys i get it. I wont turn. Heck it'll save me lots of reloading time..

Thanks guys, you've been a great help.

Hell, this rifle is deadly accurate anyway.

 

[billmo]

You'll have more time to shoot and bench time with the gun is always more fun than bench time doing prep. Bill

 

[boogershooter]

Wow, Thanks for that education guys,youve just answered alot of questions for me as well! So Im assuming you would have a custom weapon neck chambered for a 308 to about .335,then turn the necks accordingly to? maybe .332....Is this correct?

 

[boogershooter]

Hey Silverfox,saw the article around the holidays.Nice rifle,Im patiently planning a custom 308,hate to spend the dough,but dont live too far from Hammonds,so I think in april Ill go see him to get his input...really like that A5 stock!

 

[BoydAllen]

I would get some Lapua brass and skip the turning, and remember that if you hold the bushing size constant, with thinner necks, you may be seeing a difference in accuracy due to what is effectively a different load, due to the change in neck tension. This could fool you into thinking that the turning was causing the improvement.

 

[TheSilverFox]

This could fool you into thinking that the turning was causing the improvement.

Good point

 

[TheSilverFox]

Hey Silverfox,saw the article around the holidays.Nice rifle,Im patiently planning a custom 308,hate to spend the dough,but dont live too far from Hammonds,so I think in april Ill go see him to get his input...really like that A5 stock!

Thanks dude.

The problem with custom rifles is they shoot so great that you will want more of them....

Clay is building me a new rig, Couldn't resist.... Light varmint benchrest.