Neck turning worth it on standard chamber ?

[craig6547]

Hey guys

I was getting very close to achieving the end of load development. Tested from 39.0 - 40.6 gn of Elcho 17 pushing 140 Amax from a 6.5x47. Best group was 39.2 giving me a bughole group measuring 0.093"

I went out again to confirm this wasn't just luck and the groups were scattered all over the place. 1st few rounds were hard to chamber and on inspection of the cases there was a lot of crud on the necks so I immediately thought I had a carbon build up on the neck section on the chamber. But ejecting the 1st couple of non fired rounds showed some scuffing on the bullet which I am thinking was the friction of the bullet against the carbon build up. This also got me thinking about run out and how the necks might not be fully uniform. Even though my chamber is a no neck turn would it be worth turning the necks for concentricity and a better chance of less runout ? Seating for is a Forster micro seater.


Craig

 

[tenring]

What is Elcho 17 powder? New to me. The first suspect for neck "crud" is a powder charge too low (neck not sealing), but with no guide on that powder and its application, cannot tell.

Scuffing on the bullet can be caused by it rubbing on the chamber as it ejects at a slight angle. Turning the necks will not help. Push a tight patch into the chamber and rotate it. If there is carbon reistance, you should be able to feel it. Use an oversize brush with JB on it and rotate about 10 times and carbon ring should be gone.

 

[spclark]

Yes, moderate neck-turning (called 'skim-cutting' or 50 - 75% of the neck surface) can benefit results even from 'no-turn' chambers as the activity makes for more uniformity of case neck wall thickness and hence more even, consistent neck tension.

Still though if you're seeing scuffing on chambered-then-extracted projectiles I have to ask: do you have means for evaluating your loaded ammo's run-out? You may be getting scuffing because your bullets aren't concentric with the case body.

Another couple of possibilities:

An off-center or otherwise mis-aligned chamber. In your choice of cartridge I'm guessing this isn't a factory rifle so whomever chambered your barrel may have some opinions regarding what you're seeing.

If you have a spring-powered ejector in your bolt it could be canting each cartridge as it's being chambered & the scuffing is coming from bullet contact with the chamber surface someplace either on the way in or on the way out....

What part of the UK you hail from? That powder's not available on this side of the pond but may be imported under a different name that'd be more familiar here in your former colony. You know who makes the stuff, or its country of origin?

 

[rox]

What is Elcho 17 powder?

Think 'Reloader 17' with a British accent.

..

 

[rox]

You know who makes the stuff, or its country of origin?

Nitrochemie/Switzerland.

..

 

[spclark]

Yeah, probably RL-17.

 

[rox]

Yeah, probably RL-17.

More than probably - 100% definitely. The importer is a buddy of mine.

..

 

[spclark]

More than probably - 100% definitely. The importer is a buddy of mine.

That nails it down then! Nice to have a solid understanding of things, isn't it!

 

[JRS]

If by "standard" you are referring to SAAMI specs, keep in mind that by removing brass from the neck, you are creating even MORE clearance between the case neck and chamber. Not good for longevity, nor sealing of the brass. If the chamber is minimum spec, by all means, turn the necks.

 

[Witchhunter]

I turn only enough to make then concentric. Take the high side off.

 

[craig6547]

thank you for the replies so far guys.

I would only be wanting to turn enough purely for concentric necks so my bullets seat more centre to eliminate as much run out as possible. Is it going to be worth it ?

And yes elcho 17 is 100 % Rl 17 powder.


Craig

 

[Lapua40X]

What is Elcho 17 powder? New to me.

I don't know if it's available outside the UK ....
But it's a legitimate commercial product.
If it's like RL17 it can be pretty dirty, especially with light loads, so you've gotta keep the tube extra clean. I use RL17 and find that it's not uncommon to have to run the bore brush through the tube repetitiously, using three or four sequential cleaning cycles, to get it where I want it. Not surgically clean but I don't want to see jet black patches following the last bore brush cycle.

Some forum discussions:

http://ukvarminting.com/forums/topic/18667-elcho-17-tr140/

 

[amlevin]

If by "standard" you are referring to SAAMI specs, keep in mind that by removing brass from the neck, you are creating even MORE clearance between the case neck and chamber. Not good for longevity, nor sealing of the brass. If the chamber is minimum spec, by all means, turn the necks.

"Skimming" enough material off a case neck to just make it uniform isn't going to create all that much extra expansion. Regular annealing will counter the effects of the expansion and sizing.

As for sealing? Never had a problem with "sealing" when 60,000 psi expands the case against the chamber. Not even in large factory chambers. The brass moves out against the chamber wall immediately and completely.

 

[22BRGUY]

I would think the first thing to do would be to take a ball micrometer and measure the neck wall thicknesses in 3 or 4 places to see how uniform they are before turning. Lapua brass as we all know is pretty uniform right out of the box. Secondly, if you are ejecting live rounds and then re-chambering them and firing them, very likely the bullet runnout is going to be much worse because as the bullet is pushed sideways on extraction on the chamber wall, it will definitely push it out of concentric. Perhaps also you may have a carbon build up in the chamber even farther back than just at the neck/bore lip area. Might be a good idea to clean the entire chamber with Iosso or JB.
I personally have never reloaded with Re 17, but have read many posts regarding others results. In most cases Re17 produced highter velocities in several applications and sometimes worked well. In several others although it produced good velocity, it was very erratic. JMHO

 

[amlevin]

I would think the first thing to do would be to take a ball micrometer and measure the neck wall thicknesses in 3 or 4 places to see how uniform they are before turning. Lapua brass as we all know is pretty uniform right out of the box.

That's certainly the "reputation" however my last two boxes of Lapua .308 brass were far from uniform in neck thickness. Some were as much as .0015 in thickness variation. I just ended up cutting all the cases to .014" and didn't look back. I found that this thickness gave me at least a 60% "cut around the circumference with some cases actually being "cut" a full 360.

Made me wonder if I had some "off brand" brass that was merely headstamped "Lapua".

 

[ftrrookie]

I would think the first thing to do would be to take a ball micrometer and measure the neck wall thicknesses in 3 or 4 places to see how uniform they are before turning. Lapua brass as we all know is pretty uniform right out of the box.

That's certainly the "reputation" however my last two boxes of Lapua .308 brass were far from uniform in neck thickness. Some were as much as .0015 in thickness variation. I just ended up cutting all the cases to .014" and didn't look back. I found that this thickness gave me at least a 60% "cut around the circumference with some cases actually being "cut" a full 360.

Made me wonder if I had some "off brand" brass that was merely headstamped "Lapua".

I've had the same experience in both 308 and 223. You can take cases out of the box look at the case mouth and see thick/thin areas on the neck.
I figured if I was paying all this money for cases and I have to turn them anyway I might as well use Winchester brass for half the price. Apparently a lot of ppl had the same idea because Win brass in 308 and 223 is not to be found.

 

[bigedp51]

You do not need to neck turn good quality brass, and if the neck doesn't have uniform thickness the body of the case will not either. And when you fire these poorly made cases with unequal wall thickness they will warp and become banana shaped.

I bought some Nosler custom brass in .223 and was amazed at the uniformity of these 50 cases. And they made the cheaper 5.56 blasting ammo cases look like they were made by by neanderthal cavemen. I was very hesitant about spending $20.00 more for these cases but nothing needed to be done to them in the way of prepping.

I shoot the Nosler cases in my bolt action and save the cheap cases for the rifles that throw perfectly good brass away and makes you go looking for it.

The cheap brass is good for giving suppressive covering fire in Zombie attacks.

And the Nosler brass is saved for long range head shots.

The following information was brought to you by the "I don't neck turn my Zombie brass reloaders association".

The British Movie "28 Day Later" Humour, and a neck turning horror story.

 

[sbhooper]

That is funny, but a bit over the top. I have never had any problems getting the accuracy that I wanted (sub-minute) without turning any necks. I guess that if I was splitting hairs and shooting bench rest or something, that may be different. I guess it just depends on what you are trying to achieve.

A buddy of mine swears that neck tension is far more important than type of brass or even exact powder loads. He has lots of experience to back it up. He turns most of his brass I think.

 

[Webster]

If 60,000 PSI always seals the neck against the chamber why do the necks turn black on the O.D.? I usually steel wool them to clean them up.
In Tony Boyer's book he shows the difference in the soot pattern on the neck O.D. comparing a 2 lug and 3 lug bolt.

 

[bow shot]

+1 on the Nosler brass. Very, very impressed. Norma brass, prepped by Nosler.

I'm actually turning some LAUPUA right now. Never had to do that with any Nosler.