Brass prep

AirborneEScouter

Lil-Rokslider
Joined
Apr 23, 2018
Messages
283
Location
KS
New to reloading and starting slow by perfecting brass prep before moving on. I have read extensively on the subject but want to answer a simple question here. I have a vibratory tumbler, an ultrasonic cleaner and now a FA rotary tumbler using stainless pins. The rotary tumbler has certainly proven to be the ultimate in cleaning the cases but I’m still finding a little carbon residue in the primer pocket. I’m curious how clean these need to be - I do have a pocket cleaner brush and can easily knock this out but curious if it’s necessary - see attached a pic of a typical case after 2 hours in the tumbler. Maybe another hour in the tumbler would work, or a different formula in the cleaning solution (I’m using a non-scientific 3 second squirt of dish soap and about a teaspoon of lemi shine). Would you go the extra mile to scrape out this amount of residue?
 

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Joined
Nov 20, 2018
Messages
889
Location
Wyoming
I'm a hunter. Much dirtier primer pockets have killed elk really dead in my experience.

Precision guys may have more to say on this, but us hunters and plinkers are 100% fine with what you have. In fact I'm 100% fine with much dirtier.
 

ADR

FNG
Joined
Nov 29, 2020
Messages
26
I agree with others that you have those plenty clean enough. I am a little excessive and use a primer pocket uniforming tool though.
 

MrTim

FNG
Joined
Jan 17, 2020
Messages
98
Location
MT
I always brush my pockets then clean/tumble. Your pockets looks fine.

Side note: When tumbling with steel you are work hardening the brass to some degree. Great for the lower half of your brass but not so much for the necks. I spend more time using the ultrasonic now and reserve the tumbling for extra nasty brass and for short intervals only. If your annealing, then this is not an issue.
 
Joined
Jan 3, 2020
Messages
821
Location
Becker Ridge, Alaska
I always brush my pockets then clean/tumble. Your pockets looks fine.

Side note: When tumbling with steel you are work hardening the brass to some degree. Great for the lower half of your brass but not so much for the necks. I spend more time using the ultrasonic now and reserve the tumbling for extra nasty brass and for short intervals only. If your annealing, then this is not an issue.
Annealing Made Perfect did a study and found only the "skin" of the case is work-hardened by tumbling with steel pins: "Examination of the cross-section of a case which was tumbled in stainless steel shows no obvious deformation of the microstructure, see figure 5.1. Microhardness testing on the cross-section shows a hardness of 98HV". "4 hours of SS tumbling hardens the surface of the case wall by 15 – 25 HV. When the same case is sectioned however, the cross section of the case wall can be tested (see photo above right). This showed that no work hardening occurs deeper into the cross section. The tumbling effectively creates a harder "skin” on the surface which is undetectable even under 200X magnification or higher (Appendix 2 - figure 5.1)."
 

ephul

FNG
Joined
Jun 12, 2020
Messages
87
I've got an RCBS prep station and just brush the primer pockets as I debur and chamfer after trimming.
 
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