Neck turning question.

Spinalmath

Spinalmath

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Hi guys,

I'm beginning to do some neck turning with my lapua cases and I've notice some irregularities inside the neck of the cases.
The outside looks great, but the inside... that's another story. I'm using a 21st century lathe, cordless drill (not too fast) and some dry neck lube from Imperial.
All my neck are pretty consistent when measure after. Am I missing something? Do you think it could have an effect on the neck tension (I'm neck sizing my cases).
Thanks

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your neck is to tight on the mandrel, you need an expanding mandrel that matches the mandrel on the neck turner so that that doesn't happen.
 
Ooooo.....ya

That's looks nothing like mine and I just started 6 weeks ago....

I'll post a pic of mine later.

I think yodave is bang on.

Get a carbide expander mandrel. Did you get from 21st, or from Winnipeg??
 
Thanks for the answers!
I'm using the expanding mandrel that matches perfectly the turning mandrel. Everything is coming form 21st century shooting ie: Titanium Nitride Expander Mandrels,Titanium Nitride Turning Arbor and Expander Die Body with ring, all for 30 caliber. When I'm looking at the mandrels ( turning or expander, I don't see any difference. They are exactly the same).
About the drill, I'm running it pretty slow (the instruction from 21st century was talking about less than 300 rpm).
I'm thinking it might be my dry neck lube. The brass is getting hot very fast. I'll try something else for lubrification
 
Gunneegoogoo said:
Ooooo.....ya

That's looks nothing like mine and I just started 6 weeks ago....

I'll post a pic of mine later.

I think yodave is bang on.

Get a carbide expander mandrel. Did you get from 21st, or from Winnipeg??
Click to expand...

I got my stock directly from 21st century shooting through their website.
 
Spinalmath said:
Thanks for the answers!
I'm using the expanding mandrel that matches perfectly the turning mandrel. Everything is coming form 21st century shooting ie: Titanium Nitride Expander Mandrels,Titanium Nitride Turning Arbor and Expander Die Body with ring, all for 30 caliber. When I'm looking at the mandrels ( turning or expander, I don't see any difference. They are exactly the same).
About the drill, I'm running it pretty slow (the instruction from 21st century was talking about less than 300 rpm).
I'm thinking it might be my dry neck lube. The brass is getting hot very fast. I'll try something else for lubrification
Click to expand...

I run mine WAY slower than 300, maybe 100?? I'd have to measure. It should be minimally warm. I just use royal case lube, but I also have the TiN (gold, not silver - sorry, not carbide).

The only difference in them is the flat spot on the turning mandrel for the depth set. The expended is fully round.

It's confusing as all hell too get the parts you need to start. I love the gear, but navigating the website and making a shopping list is painful.
 
Thanks for all the comments. I'll try some new lube (and more) and to run the drill as slow as possible. I'll keep you in touch of the results.
 
If I may.

You are turning too far into the shoulder. It also looks like you're turning the whole circumference of the neck. Setup so you end up removing 1/3 to a 1/2. Your runout will be almost perfect by doing that. After a fireing they will be perfect.

It looks like your taking off way to much material.
 
frigpig said:
If I may.

You are turning too far into the shoulder. It also looks like you're turning the whole circumference of the neck. Setup so you end up removing 1/3 to a 1/2. Your runout will be almost perfect by doing that. After a fireing they will be perfect.

It looks like your taking off way to much material.
Click to expand...

Please teach us....not arguing, just asking.

From what I've read of this witchcraft, "skim turn" the entire neck to .012 or .013, and about 1/32" into the shoulder to limit the creation of the "donut".

Now, if you have a custom chamber with a throat of .###x, turn to that.

I spun all of my 6.5 brass like this, and my .300WSM brass, and my .338 brass, so I hope I'm not horribly wrong!!!!
 
Actually the flying pig is incorrect the outside of the brass looks good. To answer your question, Yes the neck is too tight on the mandril. This causes gauling and it simply gets worse as you go.
So what to do; open the neck up a few thou and use a lubricant on the inside such as resizing lub or a good grease, remembering the lub should be removed when finished. The brass you've done can be used however it would be a good idea to use a fine steel wool wrapped on a bore brush (use a hand drill) to smooth the inside of the brass. The joys of turning necks.
Enjoy
 
Seems like you guys know what you're talking about....so I'll ask here...

I have the 21st system. What if a donut forms?? They don't have an inside neck reamer.
 
I never cut into my necks, I cut up flush to them and that is it. If I get a donut I full length size my brass to push the donut to the outside and then turn the necks again, in my mind reaming is a bad idea, but that is in my mind.

the gaulling is caused by to dry a neck, you need more lube, imperial sizing wax works best. hand turning, as painfull as it sounds produces better results in my world, I use power when lots of material needs to be removed but I do the final cut by hand.

I run my cases over the expander mandrel in the press and neck turn right away, religiously, because once you move the neck with a die it will eventually relax somewhere effecting the tension.

slow and steady wins the race, 10 cases a day for 10 days gets 100 prepped ready to load
 
"DO NOT" use a dry graphite or mica powder, you must use a oil, grease or Imperial Sizing Die Wax. The case neck needs to "float" on the wet type lube and not bind on the turning mandrel.

Neck-Turning Basics

http://www.accurateshooter.com/technical-articles/neck-turning-basics/

NO DRY LUBE

Your brass is screaming in pain from your Ewok methods.

dry_zpsbvuxp9sf.jpg


You only need to remove 75% of the neck irregularities and just barely touch the neck-shoulder junction. Meaning your not circumcising the case necks, you are just removing the least possible amount of brass to make the necks more uniform. And on the vast majority of factory rifles neck turning is a total waste of time.

Below is a example of a case with .0025 of neck thickness variation, and even after neck turning the case neck is not centered with the axis of the bore.

neckcenter_zps94286f86.jpg


The best brass is Lapua and it is noted for its quality and uniformity and if you do not have a custom tight neck chamber neck turning and bushing dies are a waste of time and money.
 
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