Case Trimming Problem Issue??

[nosler06]

Last night I was prepping some .308 brass and have found a large ring of brass around the neck of the case after trimming. I am wondering if there is a problem. I am having to aggressively de-burr the case mouth after trimming to remove this lip around the outside of the neck. I am wondering if maybe I am pushing too hard while trimming or is the cutter head dull? I also wonder how many cases can be trimmed with one cutter head before it needs to be replaced. I have only trimmed approximately 250-300 cases with it so far. Thinking I should get more trims out of a cutter head than that. Any thoughts?

 

[kraky]

What you describe to me sounds very normal. It even sounds like a prefered action while trimming. If you are getting a smooth cut that's all that's important. As you trim more you'll probably also see and get a feel for how hardened necks trim verses softer more annealed trim. For me federal and Norma are the smoothest during trimming. I would say don't worry unless you are getting chattering and rough "saw rip" appearance.

 

[HomerOz]

G'Day Fella's,

Nosler06, you will always have some amount of case brass there, after trimming.
As you have already stated, the cutter may be dull?
Now unless you have trimmed a couple of Million cases, this normally shouldn't be a problem, as brass is quite soft as metals go.
The other thing I do that maybe of some assistance, is I initially start the cut with some amount of force on the cutter but when approaching the final length, I reduce this force to almost nil!
The Lathe equivalent explanation of this is, A Roughing cut, followed by a Finishing cut.
What then happens when I start de-burring, is there is a weak spot created by this almost nil force that I applied to the cutter and the ring of brass falls off intact!

Further to this, can I please inquire into the brand of trimmer you are using?

Hope that helps

Doh!
Homer

 

[nosler06]

I have a RCBS case trimmer pro model. Like I said I may have trimmed 250-300 cases with it. I am wondering if my de-burring tool might be getting dull as well. That tool I know has trimed thousands of cases being 40 yrs old. Inside neck de-burring is a dream with it but outside is a pain in the - well you know what.