options to get .004 neck tension?

[Winny94]

I'm looking for options to get .004" tension for a 6mmAR project. I have redding dies for it, but from what I gather, the factory expander won't give me the ~.004-.005 neck tension I'm looking for to run it out of my gasser. I see Widden makes an expander ball kit, but there's not much info on their site.
What's the material? Are they floating? Do they fit redding dies?

Anyone make a mandrel in that size?


Thanks for any help

 

[Anderson_A]

I know you could get a bushing die and get the appropriate size bushing to give you .004nt just use it without the expander ball

Or turn your expander ball down somehow

 

[Winny94]

I know you could get a bushing die and get the appropriate size bushing to give you .004nt just use it without the expander ball

Or turn your expander ball down somehow

Yea, that's my plan B. I was hoping to find something that'd allow me to uniform the inside of the case neck, but maybe on a gasser, that isn't a paramount and a bushing alone would suffice.

 

[SleepDoc]

Expand Mandrel Selector and Accessories | Reloading

Expand Mandrel | Expand Iron Tool will iron out and slightly expand the case neck. The brass will spring back to the size needed to neck turn your brass.

kmshooting.com

 

[lash]

I just use the stock Forster die expander ball and finish them off with a collet neck sizer. Yes, it is one more step, but the results are very consistent.

I’m only bumping them back down by is couple to a few thou, depending on the brand of brass, so there’s no concern regarding overworking the brass. I do not get neck splits and have over a dozen loads on this batch of Norma brass. I do anneal every third loading or so.

 

[IDbound]

Interesting post. I am having similar issues on a 240 Tomahawk. So little neck to work with makes it challenging.

 

[Anderson_A]

Yea, that's my plan B. I was hoping to find something that'd allow me to uniform the inside of the case neck, but maybe on a gasser, that isn't a paramount and a bushing alone would suffice.

How much neck tension would you get if you remove your expander ball with the die you have? My cheap RCBS die would give like .006nt without the ball on hornady brass so assuming you can get enough tension from your current die just chuck your expander ball in a drill and use some polish or 3,000 grit sandpaper then polishing compound to remove a few thou and make sure the ball is floating in your die I do that with o rings on any dies that I use the expander with anyway I don’t see any downside everything should remain concentric as it is now

 

[Scopes]

How much neck tension would you get if you remove your expander ball with the die you have? My cheap RCBS die would give like .006nt without the ball on hornady brass so assuming you can get enough tension from your current die just chuck your expander ball in a drill and use some polish or 3,000 grit sandpaper then polishing compound to remove a few thou and make sure the ball is floating in your die I do that with o rings on any dies that I use the expander with anyway I don’t see any downside everything should remain concentric as it is now

I have turned down mandrels and expander balls as well. works great!

 

[Winny94]

How much neck tension would you get if you remove your expander ball with the die you have? My cheap RCBS die would give like .006nt without the ball on hornady brass so assuming you can get enough tension from your current die just chuck your expander ball in a drill and use some polish or 3,000 grit sandpaper then polishing compound to remove a few thou and make sure the ball is floating in your die I do that with o rings on any dies that I use the expander with anyway I don’t see any downside everything should remain concentric as it is now

My die is a bushing, so I could get any tension...Im going to look at the KM mandrel posted above, but this way could be an option thanks

 

[Howland]

The Whidden set threads onto the decapping rod and comes in .001" increments. I don't know if the rod free floats. Their sets are nominal caliber size and four smaller sizes.

21st Century is going to start making expander mandrels in .0005" increments and they plan to also offer sets. I don't see them on their website yet but I understand it will be soon. Their mandrels mount in a die specifically designed for them so you will have to get the die in addition to the mandrels.