What am I doing wrong

[Cody Richardson]

Been neck turning brass this week and I keep blowing necks. It will be about every 5-6 rounds it happens, hand turning of with a cordless drill. I feels like the blade gets hung and then rips the neck all to hell. I always use line on the mandrel and the neck. Tired of losing brass!

 

[eric32]

what turner are you using?

what lube are you using?

What kinda cutter angle is on the turner?

 

[Rpbump]

Use very small cuts when neck trimming. .001" at a time will keep you out of trouble.

Rpbump

 

[Cody Richardson]

Sinclair turner and expander die.
Redding case live on the neck
Not sure on the cutter angle, bought it used off a guy with that cutter attached

 

[rl4930]

Sounds like you're taking too much off at a time.

 

[nmkid]

Sounds like you are using a wrong angle cutter. If you wish, go to the PMA webpage and click on "replacement cutters". It will then give you the option to see which angle cutter you need for the case you are trimming. Look for marking on your cutter blade and call the manufacture.

 

[searcher]

If you go SLOW and don't try to take off more than .001" in a pass, you shouldn't run into tearing necks. As the brass heats from friction when turning fast, the cutter will grab ahold of the neck and rip it open as you have encountered. The thinner the neck and the sloppier the fit on the turning mandrel, the worse things will be as well. Seeing how you got this cutter second hand, if your brass is not cleanly being cut into multiple circles of off-cut shavings, you may very well also need a new or sharpened cutter. At $10.00 or so for a replacement Sinclair cutter, I'd go ahead and put a new one on. Having a tight fit on the mandrel, removing small amounts at a time, slow turning speed and a sharp cutter head should remedy the problem.

 

[Cody Richardson]

Thanks for all the tips! Also found out my cutter angle is 20 degrees from when I was turning 308 brass. I need to order a 30 degree ASAP.

 

[JohnKielly]

Not familiar with Sinclair's but is there any chance that the cutter is the wrong way round?

 

[jcampbellsmith]

I would be surprised if you have a 20 degree cutter, unless someone has had it custom ground.

You haven't confirmed which model of Sinclair neck turner you are using.

http://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/neck-turning-accessories/replacement-neck-turner-cutter-standard-prod33869.aspx

http://www.sinclairintl.com/reloading-equipment/case-preparation/neck-turning/neck-turning-accessories/replacement-neck-turner-cutter-40-degree-prod41906.aspx

Are the two Sinclairs cutters available and they work with the Sinclair Neck Turner model #NT-1000, #NT-1500, and #NT-4000 Premium Tool.

I have used the NT-4000 for 6 or 7 years and use a light oil as lube on both the mandrel and the case neck. I've been very pleased with the results.

Regards JCS

 

[MrMajestic]

It's your lube, try something else. I use Ballistol because it's in easy reach however many others work. I put some in a small container and dipped the necks in it.

 

[Dusty Stevens]

When i use a particular mandrel setup i have that is tighter than usual i use a mix of stp and marvel mystery oil. A little goes a looooong way.

 

[Brians356]

Thanks for all the tips! Also found out my cutter angle is 20 degrees from when I was turning 308 brass. I need to order a 30 degree ASAP.

The angle of the cutter only comes into play when you reach the neck / shoulder junction. A too-shallow angle could cause you to dig into the shoulder if you don't stop advancing soon enough is all. It would have nothing to do with ripping up the neck well away from the shoulder. What am I misunderstanding?