K&M or Sinclair Expander Mandrel Tool

[Phil3]

After experiencing increased neck runout using a full length Redding resizing die with carbide expander ball, I have decided I need to iron out dents and expand the neck using a mandrel tool. Neck runout without the expander is about .001", (about the same as neck thickness variation) but with carbide expander jumps to about .004". I presume the mandrel is used after a full length resizing (this is for an AR15) and then expanded using the mandrel. I welcome guidance on how to use, as well as whether the K&M or Sinclairs is a better bet. The Sinclair mandrel floats on an O-ring so it can center in the case neck. I do not think the K&M does. Reloading press is a Forster Co-Ax.

Thanks.

- Phil

 

[SmokinJoe]

Can't address your AR-15 woes, but have a fair amount of experience with expanders. I did not care for the older Sinclair expander that used a set screw to hold the mandrel in, so had settled on the K&M Expandiron. With the new Sinclair that is now on the market, it would be close to a toss-up. If you aren't already using one brand or the other, just look at them both & go with whichever appeals to you the most. They are both quality items. Using the Co-Ax, either should work equally, since the die floats in that press. Good luck sorting your brass problems out.

 

[HHI6818]

http://varmintal.com/arelo.htm#Anneal


I have used this method for several years.

 

[DaveWhite]

+1 on the Sinclair tool. I just bought one with a .30 cal mandrel and processed 100 rounds of new Lapua brass. Just used a touch of lube on a Q-tip on the inside of each case mouth and then wiped it clean afterward. Nicely made tool. It ironed out the only casing that had any kind of dent in the lot, and afterward I could not tell where that ding had been (though I marked the case head as a tell tale.

 

[NorCalMikie]

Any of you folks that use a Co Ax press would know more about it that I do as far as dies fitting. I needed a expander die for a Wild Cat project that I built so I picked up a new K&M expander and a new Sinclair expander.
I didn't like the feel and the way the K&M worked but the Sinclair has worked like a dream. One pass and I went from 6BR to 6.8 with one pass. Even went from 22BR to the 6.8 with ease. My choice would be the Sinclair. Easy to change to the size plug you want and it "just feels better".

 

[bozo699]

+1 on the sinclair for me. I don't own a k&m so can't say +or - The sinclair mandrels are not perfect usually .0005 or .0006 out of round, probably good enough but?
I have a friend make them for me on a brown&sharp, they are practically perfect I have many different sizes so I can accomplish just about anything That I might need too. I reloaded for 20 years w/out this tool now that I have it I don't know how I ever was able to make ammo without it.
Wayne.