Best Time to Neck Turn?

[Lucky7]

Hey guys,
I am sure this has been covered somewhere at sometime in the past on this site, but I wanted to know when is the "best" time to turn necks and why? I understand that some "tight neck chambers" will require necks to be turned before firing, but if not, is it better to turn necks before Fire-Forming or after? I am fairly new to reloading so just trying to get a better understanding? Also, what would be the ideal thickness on say "Lapua Palma" brass for a FTR .308 Rifle? I have heard the term "trim thin to win", so I am very curious about that statement? Any feedback would be greatly appreciated, thanks!

 

[Dusty Stevens]

Turn thin to win means having enough clearance. If theyll chamber without turning then just turn deep enough to get about 75% around the neck. In other words dont turn off more than you need to

 

[Lucky7]

Turn thin to win means having enough clearance. If theyll chamber without turning then just turn deep enough to get about 75% around the neck. In other words dont turn off more than you need to

Thank you for the info? Should this be done before or after FF?

 

[Dusty Stevens]

Before

 

[Lucky7]

Before

Ok, that is what I have been doing currently using the 21st Century neck turning lathe. I just wanted to see if there was a better way, and what would be the reason. Thank you.

 

[Dusty Stevens]

No you got it goin your way- keep it up

 

[Shaggy357]

A buddy and I ordered Lapua brass for new pistols match chambered with same reamer. We bumped the shoulder with the sizing die to ensure the brass fit in our chambers. We then seated a bullet in a sized brass, measured the case neck diameter with bullet seated in place and then confirmed diameter we would need so we had .0015" clearance. All brass was then neck turned. Some necks were hardly scored with the bit. Others trimmed full diameter. Even Lapua brass, as fine as it is, needed turned to confirm concentricity. We then loaded, fired for score, then trimmed after first firing. Shoots wonderfully today.

Steve

 

[Lucky7]

Thanks all for the info.

 

[Joe R]

Dusty Stevens said:
Turn thin to win means having enough clearance. If theyll chamber without turning then just turn deep enough to get about 75% around the neck. In other words dont turn off more than you need to

Dusty,
I'm not sure I understand your comment, would you mind explaining why it would be detrimental to turn necks down to .012. The Lapua Palma brass usually runs .014-.017. It seems to me that having more uniform necks would be beneficial. I'm obviously missing something, can you help me understand?

Kindest regards,

Joe

 

[Dusty Stevens]

Dusty,
I'm not sure I understand your comment, would you mind explaining why it would be detrimental to turn necks down to .012. The Lapua Palma brass usually runs .014-.017. It seems to me that having more uniform necks would be beneficial. I'm obviously missing something, can you help me understand?

Kindest regards,

Joe

Just sayin no need to turn brass off unnecessarily. The more clearance you have the more it works your brass upon firing

 

[Joe R]

Dusty Stevens said:
Just sayin no need to turn brass off unnecessarily. The more clearance you have the more it works your brass upon firing

Ah, yes. That is one of the benefits of annealing, it mitigates that. I appreciate your response.

Isn't it beneficial to have thin necks to help reduce/control neck tension?

Thanks,

Joe

 

[Brians356]

Isn't it beneficial to have thin necks to help reduce/control neck tension?

Joe,

You know me by now. I ask questions:

* Is it always beneficial to lessen neck tension?

* Does a thinner neck wall always produce less neck tension than a thicker one?

* How did you arrive at .012" neck wall thickness as (presumably) optimal?

* How thin can one safely turn neck walls? (If .012" is good, wouldn't .009" be even better?)

It occurs to me that the more brass you turn off the neck, the more critical the depth of cut into the shoulder becomes, and the more likely one could inadvertently weaken the neck/shoulder junction.

-

 

[Joe R]

Hi Brian,
I like people that ask questions, that's how I learn and consider different viewpoints.

I can only attest to my experience with my tools, my methods and my rifle, so change any of those and you may get different results.

I used to turn to .014 and shot several thousand rounds with that and got pretty good results. Then when I really started to focus on neck tension a couple of friends/mentors (Ben Steinsholt and Donovan Moran) suggested that I try going thinner so I went to .012 and tested 30 rounds each. I found that the thinner necks produced slightly better results for me. It may be due to the fact that I also was able to reduce neck tension by expanding the necks more precisely.

Encouraged by those results I took 200 cases down to .010. The results were very encouraging on the first firing, however getting the brass ready for a second firing after resizing the brass my bullets just fell in the powder because the sizing die did not constrict the neck enough (I use a RCBS die without bushings). Well, with matches going on every other week I put that project on hold. I have since bought a sizing die with small enough bushings (.324) to actually squeeze the neck down enough, but I haven't gone back and restarted that experiment. Lots of stuff going on right now, my son is going through match and graduating from medical school and having to relocate. An upcoming trip to Europe for a couple of weeks, being mid-range director at Bayou, etc...

For now all my brass is turned down to .012. Having said all of that, I've read books that benchrest guys take their 6mm down to .008. That may not be realistic with a .30 caliber, but it would interesting to find out for sure.

Joe

 

[Joe R]

By the way Brian,
the flip side of all my efforts to improve my ammo and my scores is that there are several guys at my range that are national record holders and they only skim the necks somewhere around .0145. It is easy to loose focus and get sidetracked. Good ammo is important but turning 1/4 MOA ammo into 1/8 MOA is not productive. Many guys will quickly tell you that matches are not won in the reloading room, they are won by guys out on the range that know how to read the wind and mirage. Gotta keep it all in perspective.

Joe

 

[Brians356]

Joe,

Thanks for taking the time from your busy life to expound on your thinking, good points and definitely food for thought.

Brian

 

[waldo1979]

I trim my brass on a 21st Century lathe. I only knock off the high spots and IIRC my Lake City brass is turned to 0.013" (it's such a lucky number why not!). I haven't tried going any thinner.

My process for initial prep is FL size and fire with a max load (vs a light load for full expansion). Then I come back FL size (always), trim, neck expander die and then I turn. The lake city brass tends to flow significantly for me on the first firing so I save turning to the 2nd loading. My Lapua brass is significantly harder and doesn't flow nearly as much.

I really dislike breaking in new brass as it takes so long to turn. I tend to do 200 at a time and end up losing around 10% to reloading mishaps and just poor shooting brass. I also use a Giraud Triway trimmer which definitely speeds up operations.

Neck turning for me is all about concentricity and less about tension. This could be because I'm using a PTG reameed benchmark barrel which has fairly loose tolerances around the necks. If I was using a match speced chamber (in retrospec I would have asked benchmark to use a match reamer) I'd be more concerned about getting a tight fit. I don't remember exactly how much space I have in the chamber but it's definitely on the lose end.

I would love to shoot F-TR but my schedule only permits a monthly 300 yard hunter class bench rest match. I've done all shorts of component sorting and sorting by concentricity definitely makes the biggest difference. I've recently switch to a floating toolhead Dillon 550B from Whidden and my concentricity appears to have improved significantly. Before I was using a Harold's turret and before that an RCBS press.

Turning on a single stage press I'd get an average 0.003" run out with an extreme of 0.005-0.007". After neck turning my extreme was 0.004" and an average of ~0.0015". I haven't sampled a large batch with my current setup but the small sample set I did on my initial reloads show all sub-0.001" which was shocking. FYI, I'm checking on a 21st Century concentricity gauge w/ wheel just behind the ogive.

At this point I could tune my loads to a few thousands jump and 0.2gr better but the loads exceed my shooting abilities and stock/rest capabilities. So now I'm focusing on mostly improving the shooter. The baffle design at my range creates very strange wind patterns and makes reading the wind a challenge. Luckily we have some amazingly talented shooters who have been giving me some excellent tips.

 

[waldo1979]

I just sampled 82 pieces of loaded ammo loaded on my new Dillon 550B. I got a 0.0029" average with 0.005" extremes. There were a couple stretches of sub-0.001" followed by a stretch of 0.004" =( My Harold's is definitely producing better ammo.

Also, I've lost more brass in this box due to press setup woes.

Anyway, sorry for going off topic. Just didn't want to give misinformation.

 

[Brians356]

Not too far off topic. You did mention turning necks. Good stuff, Waldo.

It's amazing, there are probably ten guys who could show up and win any particular high-value BR match in the country, and if you made a flowchart of their loading methodologies and compared them, they're probably all significantly different. There are many different paths to consistent loads, but as you say, it's the nut behind the butt, and shooting the conditions.

I do keep coming back to Virgil King, who felt light consistent neck tension was they key to putting all the pills through the same hole (groups consistently in the "ones", indoors). He shot a tight-neck 22 PPC which, once cases were prepped, required no neck sizing after firing. And he seated with an inline Wilson die by hand (no arbor press!) After neck turning and firing the case, he used sandpaper on the inside of the neck until he got the perfect ID. Using only Remington (!) 52-gr flat-base benchrest bullets, he could feel the bullet click gently into place when he seated it, since the heel of the bullet left a shallow detent ring in the neck after a couple of firings. He became acutely attuned to the seating feel, and if seating didn't feel quite right, he'd set that case aside. I'm not sure that we can approach that level of consistency using a press, even with a pressure gauge.