Case neck runout problems

[dm1779]

Current reloading setup:

RCBS Rock Chucker
Redding Shell holder #1
Forster .308 FL BR sizing die
Nosler Brass (2x fired)
Imperial Sizing wax
Sincliar Concentricity Gauge

Process:
1. Check neck runout after firing brass - .000->.001
2. Apply sizing wax from case base to shoulder
3. Apply (using a q-tip) small amount of sizing wax to interior of case neck
4. Run case through sizing die
5. Wipe case clean
6. Check case neck runout.

Post sizing the case neck runout can be anywhere from .001->.005+.

I've tried neck turning and it's brought some of the cases back to .002" or less. However, I've found sometimes a second run through the resizer will also bring them back to .002 or less.

Is there something in the way I'm resizing, my tools, my brass?

 

[bcrich]

Re: Case neck runout problems

I use a cheap lee die set for my 308 and also get similar results but have found that when sizing a case and turning it 1/4 turn clockwise for a second pass fixes the runout to .001+- Good enough for me!

 

[fw707]

Re: Case neck runout problems

How much is your neck (and bullet) run-out after seating your bullet?
Isn't that more important than the empty case?

 

[dm1779]

Re: Case neck runout problems

With some of the case necks that were .003-005" I was getting at most .005 bullet run out. However with the case neck that were .001" I was typically getting .001" on the bullet

 

[427Cobra]

Re: Case neck runout problems

Try raising your expander ball a little higher so it starts expanding when the neck is still supported in the die, and lube the inside of the necks with graphite powder.

 

[427Cobra]

Re: Case neck runout problems

Also since your using the expander ball any neck thickness variations are moved to the outside, unless you neck turn you'll always have outside neck run out due to the thickness variations.

 

[Topstrap]

Re: Case neck runout problems

Not trying to be a smart ass but how does the gun shoot? Sometimes knowing too much is a bad thing. It's nice to try and make everything in your reloading process perfect but unless you're shooting lil tiny one hole groups at a BR match a lot of this stuff really isn't necessary for the types of matches we are all shooting.


Good luck

Topstrap

 

[MALLARD]

Re: Case neck runout problems

if your using your expander , i'd say that is the problem. I dont use expanders. I just get the right size bushing to size my necks to the diameter i want.

try running your press slower, try using o rings to free float your dies.

 

[dm1779]

Re: Case neck runout problems

TopStrap - typically on 500/600 F-Class shoots I'm hitting X/10/9 ring. However I've had the occasion 6/7 ring hits with no variable changes. So 90% of the time it's shooting great.

Went over to a fellow reloading place last night for some controlled testing over 3 different resizing dies. 2 Forster and 1 Redding die, all yielded the same results after the fact. We then pulled out his case neck micrometer and determined that about 50% of the brass I'd brought over had serious case neck thickness problems.

My plan now is to start neck turning my brass that's .003" runout or greater.

I think after the brass has reached the end of it's life, I'll just bite the bullet (pun intended) and buy a lot of Lapua brass.

 

[gau17]

Re: Case neck runout problems

Since you neck turn you should have an expander die right? Just run them thru there after sizing. It should straighten the neck out.

check this Sinclair video out.

http://bcove.me/x8fzuz4x

 

[dm1779]

Re: Case neck runout problems

Mallard - The Forster resizing die it has a rubber bushing already setup there. I'd tried it without the expander ball in there and had zero net change on the case neck runout. Problem then is that the case neck diameter is to skinny.

I'll look into the Redding Type S FL bushing dies. The recommended dies are typically one or two thousands less than the diameter of a fired piece of brass?

 

[dm1779]

Re: Case neck runout problems

Gau17 - I'm utilizing the RCBS Case Trim Pro with the case neck turner that comes with it. I've contemplated upgrading to the Sinclair case neck turner, though haven't yet.

 

[gau17]

Re: Case neck runout problems

Send your sizing die to Foster and have it honed out. Hope this helps. I use one and love it. I wish they made one for 6.5 Creedmoor.


"CUSTOM neck honing of Forster FULL LENGTH SIZING or NECK SIZING DIE to your specification. We custom hone the inside neck diameter by using a diamond stoning process. We enlarge the inside diameter to prevent over-sizing of the case neck due to thick neck walls. You may require this service for two reasons: 1) If you use some brands of brass cases, such as Norma or Lapua, which have thicker neck walls. 2) If you do not intend to outside neck turn case necks that have thickened after repeated firings. Please specify desired inside neck diameter. Note: 1) No more than .008" stock removal from your existing die neck diameter is possible. 2) Honing is done in increments of one half thousandth of an inch (.0005"), meaning that your specified inside diameter must be either.XXX0" or .XXX5".
$12.00 plus actual return shipping cost & insurance Please allow 1-3 weeks."

 

[flashhole]

Re: Case neck runout problems

Take a case that has little (if any) runout. Lube it and run it into your sizing die before you tighten the die down onto the press. This provides good axial alignment of the die to the press to the center line of the ram. Check for improvements with cases you know to have runout issues.

 

[rommelj]

Re: Case neck runout problems

With my 6.5-47 Lapua, If I full length size the brass using the Forster Benchrest die, I'm getting run-out as high as .005" on my loaded round. If I just neck sized the brass using Wilson die, my run-out dropped to within .001".

http://www.youtube.com/watch?v=uJrw6o7bZNY&feature=g-upl

With my 7WSM, I full length resized the brass using RCBS two die set but seat the bullet using Wilson. My run-out is between .001" and .002"

http://www.youtube.com/watch?v=9-il_zpp0-Y&feature=g-upl

 

[cowbuyu]

Re: Case neck runout problems

If you want precision ammo, reload with bench rest tools, check out Sinclair as a source. The benchrest folks are fanatical about ammo prep. If you want to use standard dies or even competion style dies, there are a couple of simple things you can try to eliminate bullet runout in most of your rounds, but sometimes cases start out as junk and stay that way no matter what you do...cull them and use them for blasting ammo.
After you have the necks all turned to a uniform size, try loosening your expander neck lock nuts so the expander can essentially "float" when pulled back out of the case. After you seat your bullet in the mouth of the case, give the case a quarter turn or so and re-seat the bullet. Sometimes that will help with run out as well.