neck turning question

[canuck]

I recently received some new norma 7mm saum brass. This stuff is so tight that even with an over sized expander it still is way too tight( even with lube). I was thinking of buying a 30 cal expander mandrel and getting it turned down to 2 thou larger than my current one. What do you guys think? Any other suggestions?

 

[Boyd Allen]

Some of the neck turning tool manufacturers will make custom expander mandrels for quite reasonable prices, I would call K&M and perhaps PMA tool. Good luck. let us know what you find out.

 

[Mozella]

I recently received some new norma 7mm saum brass. This stuff is so tight that even with an over sized expander it still is way too tight( even with lube). I was thinking of buying a 30 cal expander mandrel and getting it turned down to 2 thou larger than my current one. What do you guys think? Any other suggestions?

It's not absolutely clear, to me at least, what you're asking. I think you are saying you have some brass you wish to turn by first inserting an expanding mandrel in the neck so that it will be properly sized to fit over the turning mandrel associated with your neck turning lathe? But even after expanding, the neck is too tight to fit properly over the turning mandrel. Do I have that right?

If that is the situation, I would first measure both mandrels to be double-sure you're using the correct components. Then I would anneal the cases before I inserted the expanding mandrel.

 

[R.Morehouse]

When you run in your expander give it about a 10 count before removing it. Brass likes to spring back. Let it rest for a bit and it will not spring (at least as much ). Just went through this using a Sinclair expander in SS and Sinclair carbide turning mandral. After 300 pieces of Lapua brass turned over the weekend all went well using this method. With out the pause the brass was to tight for the carbide turner....Rick

 

[Wilbur]

Whatever you have to do, just do it. I don't believe cases need to have necks exactly the same but they all need to hold a bullet when sized with the same die. Using a mandrel that's too tight will heat up and cause necks to vary quite a bit on one hand and be entirely aggravating on the other. Again, do what you gotta do to loosen up the process. In my opinion, a mandrel that's too loose is better than one that's too tight. "Just perfect" is somewhat hard to achieve.

 

[Boyd Allen]

+1

 

[canuck]

Whatever you have to do, just do it. I don't believe cases need to have necks exactly the same but they all need to hold a bullet when sized with the same die. Using a mandrel that's too tight will heat up and cause necks to vary quite a bit on one hand and be entirely aggravating on the other. Again, do what you gotta do to loosen up the process. In my opinion, a mandrel that's too loose is better than one that's too tight. "Just perfect" is somewhat hard to achieve.

That was my thinking which is why I stopped the process 15 cases in.

 

[canuck]

When you run in your expander give it about a 10 count before removing it. Brass likes to spring back. Let it rest for a bit and it will not spring (at least as much ). Just went through this using a Sinclair expander in SS and Sinclair carbide turning mandral. After 300 pieces of Lapua brass turned over the weekend all went well using this method. With out the pause the brass was to tight for the carbide turner....Rick

I did leave them about 10 seconds but didn't seem to do much and even ran them through the expander twice again with no success.

 

[canuck]

After giving this some more thought I think I may even get an additional expander to try. I will have it done about 4 thou more than I need and then run them through a regular neck sizer with expander . I realize I would be working the neck more like this but maybe I would get more consistency( just a thought at this point but I will give it a go)...

 

[Wilbur]

I don't think that's a good idea...just get an expander that works, turn your necks, THEN resize. Are you expanding then resizing the necks before you turn them? If so...stop doing that. I don't think that's the case but had to say it.