Neck turning Alpha brass in 6mm GT

[neckturner]

Don’t sweat it at all, and I have a bunch of loads for a GT if you get lost.

I may take you up on that when the barrel arrives. Right now, my sources are Hodgdon and QuickLoad. I've settled on StaBALL 6.5 and 115 DTACS - QuickLOAD has DTAC info, and while other sources do not, 110gr A-TIP info is a good reality check against the QuickLOAD data, which I'll refine once I've got some fired cases to determine the internal volume (water weight).

 

[NiteQwill]

I personally think you're overthinking it. But if you want to create more work, then I guess you have more time than I have at my own bench.

 

[neckturner]

So for those keeping score:
- I'm really uncomfortable with tapered neck thickness
- I'm somewhat uncomfortable with thinning the neck to fully even the neck thickness (would be about .0125)

So I'm splitting the baby at .0135", as below. I don't mind neck-turning, you don't have to do it with every reload. .0135 becomes a skim near the mouth and a full, but not deep, cut near the shoulder.

Thanks all for your input.

 

[Tesoro]

Do use you use the k&m case holder with the tightening ring option? or whatever it is called. and the ergo handle for the cutter?

 

[neckturner]

Do use you use the k&m case holder with the tightening ring option? or whatever it is called. and the ergo handle for the cutter?

For the case-holder, I found the K&M bit into my hand and often would not stay tight, so I switched to a Sinclair ( https://www.brownells.com/reloading...rning/neck-turning-caseholders/?sku=749002493 ) which tightens very easily and has very little wobble.

For the ergo handle, it certainly looks comfortable! If the current setup start to hurt my hand - it never really has - might try it.

 

[Tesoro]

I was talking about the addition k&m offers. Very nice. But it is slick so I added gator tape non-skid.
the ergo handle is well worth the money too.

 

[AM_ARixon]

Figured I'd jump in and join the discussion. I've measured an embarrassing amount of case necks and there can be a slight taper in necks in every company's brass, specially when you are comparing right at the neck shoulder radius, it just depends on where the material is being pushed. I had extensively tested neck tension and found that the interference fit and ID being consistent and round was by far the most important for consistent release of the bullet and down range results. In our manufacturing process I optimized our tooling to achieve very consistent ID and cylindricity of that inside neck measurement. If you are only controlling the outside then that can create inconsistency on that ID, which we have seen to cause more variation. That is why I always tell everyone to ID mandrel for best results as you need a consistent interference fit. That is also why pull through balls are not good to use because they walk all over. The whole length of the neck needs to be engaged by the mandrel. Keep the inconsistency on the outside and not what is contacting the bullet.

Also, to get a true measurement the only way to do it accurately is to section the brass because you are approaching the radius and are assuming where you are measuring is contacting the mandrel, which it very well could not be as that is where the radius starts roughly. Also, you must know that whenever you bend and form a radius there will be material build up, not only does that cause thicker walls at that location (which we do plan for and design tooling specifically for it) but also that area is stronger and will not see the deformation that the less supported side walls of the neck does. One of the reasons you want to try keep the constant diameter section of the bullet forward to the neck shoulder junction as that section will hold and release a bullet much differently than the constant diameter section of the neck.

I must admit, I have yet to see real data that singles out neck turning as a performance gain of any kind. If you are doing it for chamber neck clearance then okay, I'd just get a correctly spec'd reamer, which we have found .004-.005 of clearance to be optimal.

From what we have studied, the most important variables that we can control as brass manufactures and as reloaders is consistent hardness and consistent ID. Those are what really effect down range performance.

 

[neckturner]

Thank you for your thoughts.