Neck turning--confused-told don't do it

G

gray wolf

Guest
Hello folks, This is Gray wolf in Maine.
I have a new stock rifle that shoots very well with factory ammo,less than a 1/2'' at 100. I have begged and borrowed 400 once fired cases and have some from my rifle 270 Winchester. I will be loading Sierra 135 SMK's H-4198 powder.
I uniform the primer pockets and do the flash holes. I trimmed all my cases.
I use the Sinclare tools. I also anneal my brass.
Here is the Question:I wanted to try neck turning just to take a little off the brass to clean up the necks. I thought I would get the Sinclare
NT-3000 kit, And there run-out gage. I called them up and they told me
not to turn the necks on once fired brass.
To only do it with new brass, They said funky things happen to brass that has been once fired and I would be wasting my time and it would not come out right.
I was disappointed! They said I should just get there #09-175 concentricity gage and look at the cases and loaded rounds with that.
I have a ball mike and most of my cases vary from .012 to .0135 when I check the neck thickness. So naturally if I put them on the gage and check run out they will be off and I will have no way to correct it. Also if I load with the run-out from the uneven necks I am sure to have run-out when I measure on the bullet.
Did I waste my money on the run-out gage? What good will it do me at this point?
It's like checking the brakes on your car and not having any parts available to fix them if they are bad. Will it turn out bad for me if I clean up the necks on the once fired brass?
I am sure I must have left something out here, if anyone need more info. I will try to tell you. I can't get into bench rest and I am just trying to be a better shooter and do the right thing here.

Thank you

G.W.
 
If that's a 270 win and your getting 1/2" groups....not going to be much to improve on there. The only thing I can say, is get new cases, all from the same lot. Mixing cases is a bad idea. Also, I've never heard of anyone using h-4198 in a 270win. Try h4350 and h4831...I prefer the h4831. Listen to the sinclair guys...they know what there talking about but in reality...no need to neck turn for a factory gun that's shooting that well.

Hovis
 
Sorry my bad-----It is H-4138 I said the wrong one.

GW.
 
gray wolf said:
I have a ball mike and most of my cases vary from .012 to .0135 when I check the neck thickness.
G.W.
Click to expand...

If your brass is only varying 1.5 thousandth and you are dealing with a factory chamber in .270 win. I think you probably have nothing to be gained, and the potential to make things worse by neck turning. Especially with already fired Brass.

Dick
 
Hi from Aussie Gray Wolf.

I benchrest a 270Win here in oz, with some success, I neck turn all brass, and will re turn it once fired. It worked fine in a factory remington barrel, and even better in a krieger. My only caution would be to take off as little as possible, as your factory neck will be around .310 dia, whereas a 135gr Sierra in an 11thou neck will be around .302 or .303. This gives you a degree of misalighnment in the round before firing, which isn't good. I overcame this with a custom reamer from Dave Kiff, neck dia .306, with a short leade, as you may also have difficulty getting the Sierras close to the lands in a factory chamber. Although a long range gun, mine puts up .2" at 100 yds all day long.

Happy shooting

Jeff
 
Yes I do--I guess it's been a hard day at camp. I am really not a dumb sh-t.
H-4831, Looks like I should give up on this post.
 
Grey Wolf- I too have a .270 that will shoot around 1/2 in. in factory gun. I cleaned up the necks on once fired brass, and every thing was fine with it afterwards, but I gained nothing. Even with new brass and turning, it didn't help to any degree measurable but I had added cost. The experience was good for me to learn neck-turning and that isn't a bad thing as I now shoot benchrest. Do as you want while understanding that you may not gain a whole lot of accuracy improvement. When that barrel is toast, put a custom barrel on it with a little tighter chamber, buy new brass (Norma and Federal makes some good ones but I would buy Lapua if they make it) and go from there. Randy J.
 
Thank you for the answers,

Jeff---
I hear what you are saying. The brass I have separated out is about
.0135 to .0145 Thou. I was going to do a clean up cut and try to keep the brass at about .0125 . I understand about not taking to much off and making the brass to thin. My loaded rounds now are about .3045 my fired cases are
.308 I am thinking my chamber is about .309.
If my fired cases are .308 and the loaded rounds were .304 figuring spring back of perhaps .001 I guess I have about .0025 thou. free space around the neck when the round is in the chamber. So it looks like I should choose my thickest cases and take off as little as I can and like it has been said---Just clean up the neck.
My other thought was about the run-out gage? It seems that it will only tell me how bad my run-out is before and after loading and leave me with only my loading tools to correct anything. At that point if it is the necks
being out of round from the start I will have no way to go.
That was my thought about did I waste my money getting the run-out Gage. So many people say your wasting your time turning for a Factory gun.
It makes me think I will be feeding a dog that wont hunt.
Yes the SMK's are way out there trying to reach the lands. The Sierra
140 gr. game king hollow point has a much longer bearing surface and allows for a little more bullet in the case while getting closer to the lands.

Thanks again

GW.

Perhaps this should have been in the general Discussion area.
 
From experience I can say that turning the necks for a factory chamber will only result in shortened case life from cracked necks since they'll expand more and need to be sized down more to hold bullets. That will work harden the necks and lead to cracks sooner than usual. If your necks are within 1.5 thou and you're shooting 1/2 MOA, don't waste your time.

The run out gauge will let you sort your loads so that those with the least eccentricity can be set aside for serious use.
 
I think I am going to go for it. I am 67 and been learning new things all my life. Why stop now? I am not trying to be what I am not or turn my rifle into what it is not. There is a place for everyone and everything.
I would love to do bench rest, I am a serious take things to hart kind of guy. My wife said when I got the ball Mic. " holly crap .001 isn't good enough
I can't even see a .0001 of a thou." I said "but honey you got to have one of these." now I need a 0 to 1 inch Mic.
It is a craft and I think you guy's are a special breed.
The model 70 was a gift to me, and the tools I got from tying fishing flies.
I just sold some old brass and bullets I didn't need and got the run-out Gage. I don't know how I will get the neck Turner but things seem to work out one way or an other.
I like living in Maine, we live in a small cabin (small as in small). Wife and the
Malamute Ashly, what a great dog.
OK men I think I have a direction to go in.

GW.
 
Gray Wolf,
Anybody that has a Malamute can't be all bad. Used to raise and show Mals years ago. Welcome to Benchrest Central.

Best,
Wolf Gray(Dan Batko)

"Where are we going and why am I in this basket?"
 
Turning

I would go ahead and turn 10 of them just to clean up 20% of the neck to take out any really high spots. Preferably after annealing, then sizing with a lee collet die to be sure the brass has the error on the outside of the neck. If it makes it worse, you have only used 10 pieces. I imagine it will make you feel better more than anything. I know that is why I am considering doing the same. :D
 
Thank you for re-visiting my thread.
I got the Sinclare run out gage and I did get the NT-1000 turning tool with the expander die and mandrel.
As many of you know I had a problem with bad primers and the bolt face on my new rifle was etched. Man I was pissed. Well long story short the guy at the store gave me a bran-new rifle also in 270 Win. This one is a model 70 sporter 2008 limited edition. So the barrel is a little thicker but otherwise about the same. ( I thought I did OK on this one )
My loaded rounds at the neck are .304--.3045 and my fired cases are .308
at the neck. This tells me my chamber is about .308. I thought not bad for a factory gun. The brass I have was .0125 to .0145 --so I set the tool up to give me a .0135 case neck with the ball Mic. All the necks I turned cut on one side--not even all the way a round and I just have a little shiny line at the shoulder neck junction.
So now my necks have one side or on some 3/4 that are .0135 on the cut part and vary to .0125 to .013 on the uncut part. I thought this was a decent clean-up cut.
I thought I would stop there and keep the the cut to .0135 as to save as much neck as I could. Is this correct?
Also my necks were to big for the expander mandrel so I ran them through my Redding full length die without the expander ball. Then I used the expander die that came with the tunning kit.
Well that seemed to work out fine as far as the fit on the tunning tool mandrel. But my cases had almost zero run out and after all the work they wound up with .001 to .004 run out.
I guess after they are fired again they will be OK, and then I will re-turn the necks using the same setting on the tool and use my bushing die to resize
the necks.
Wow what a long post-- I didn't know what to leave out.

GW.
 
Pay close attention to this observed FACT..... "But my cases had almost zero run out and after all the work they wound up with .001 to .004 run out."

Also note the reason why neckturning doesn't help a factory chamber. Before the bullet enters the rifling lands the neck has not only LET GO, it's completely plastered open and sealing the chamber against gas leakage. (This is the primary function of the brass case.) The bullet enters the rifling slammed against one side or the other, IT HAS TO, it has no other choice. Contrary to popular belief "concentricity of loaded rounds" goes right out the winder once the Fifty Thousand Pound Hammer falls. The case emerges from the chamber with "the concentricity of your chamber."

Your job now is simply to maintain that concentricity.

You will find all the measuring and gauging and clocking and straightening and comparing tools are moot once you recognize the issues presented by the mismatch of a crooked and oversized factory chamber mounted to a misaligned rifle and being maintained by off-the-shelf (hence misfit) dies. IMO the absolute BEST you can do is to throw away everything except a necksize-only die (NO expander ball) and reload fireformed cases for accuracy. Leave the necks as thick as possible, buy the brass with the thickest neck. Learn early to GREASE YOUR BOLT LUGS!!!! Grease every group. Every ten groups grease the primary extraction and cocking cams.

opinionsby



al
 
Before the bullet enters the rifling lands the neck has not only LET GO, it's completely plastered open and sealing the chamber against gas leakage. (This is the primary function of the brass case.)
Click to expand...

Odd you should express this Al. I've been thinking about bullet release a fair bit recently. The conclusion I came up with is, nobody knows. There is no data, and as far as I can see, no way of getting it.

Just one example: Same fifle, same brass, a 6.5/270 AI. Using 142 MKs and 4831, the rifle shoots better with the bullets jumped. Using 142MKs and 4350 (or Rel-22), the rifle shoots better with the bullets jammed. Now why is that?

Some individual rifles shoot better with a lot of neck tension, and presumably, significant neck/chamber clearance (e.g., Al Nyhus' .30 BR, Dave Tooley's .30 BooBoo, & I think Joel Pendergraft's rifle that shot the new record). On the other hand, individual rifles -- sometimes in the same chambering -- have shot best with light neck tension and close-fitting necks.

Now why is that? And why do necks, if a bit long, get a carbon ring that goes up & down? Why are some carbon rings quite even? Is there an accuracy correlation?

How would we test for this? Simple logic works good for Sudoku puzzles, the real world requires empirical results to generate a theory, then the theory has to accurately predict behavior. There are too many variables, some of which we're unaware of, to use logic alone.
 
Charles E said:
There are too many variables, some of which we're unaware of, to use logic alone.
Click to expand...

I can't really agree with this :) This IS rocket science but rocket science isn't so very mysterious any more.

On the subject of data, one thing to think about is that testing, repeatable TESTING, shows that the brass case expands to seal at 6,000-12,000 psi depending on thickness, clearance and hardness but that by 12,000psi even the hardest/thickest portions of the case have yielded. Conversely the light and thin shoulder-to-neck brass is designed to yield FIRST which acts to seal the case at the front and allow it to iron itself back to the rear. The taper in the brass case is by design, not just an artifact of mfgr. A factory neck on most rounds (excepting the new WSM and WSSM for instance...) expands to seal at under 8,000psi.

10,000 psi is the force required to engrave a bullet. It follows LOGICALLY :) that the neck is sealed before the bullet is out of it. Even excepting acceleration time. (Inertia ensures that even with no engraving force the neck will seal before the bullet leaves.... except for in those instances where one seats bullets 'WAYYYY out. That's often also when one notes the carbon ring fluctuating.)

Conversely, as one who's spent some little time making weird brass cases I can assure you that if you pus up this relationship, bad things happen. Necks too hard and thick or powder charges too light or slow will result in gas escaping past the gasket with interesting results...... scalloped and dented cases, soot clear to the base, puffs of hot gas buffeting facial tissue.. Interesting (but logical) that most failures to seal occur when a handloader trying to make a 1000yd hunting rifle out of a factory rig seats heavy bt bullets clear out to the end of the neck using the slowest powder possible.


I did fire a couple bullets into a snowbank this last winter....... one with .001 of neck clearance and one with .010 clearance ......... to try to check for in-bore yaw. Results were inconclusive. I posted pix.


On the subject of neck tension and jump...... I think that once one is convinced that the bullet is STOPPED at the lands while the neck opens and seals one must revisit ones idea'rs on the subject.....

al
 
Hey Gray Wolf, Lightman here. Even if your neck turning venture doe's not improve your already accurate rifle, you probably will enjoy the experience. Your meausurements and game plan sound about right to me, some time it helps, sometime not. I don't think you wasted your money on the run out gauge, i use mine thru the whole loading process, from sizing to seating, and it has helped me improve my procedures. Good luck and Good shooting, lightman
 
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