Removing Carbon from Inside of Necks
 

Didn’t want to derail the thread regarding “how to clean” so will start this new one....
What are your thoughts/experience regarding the removal of carbon from inside necks as a part of brass prep?
I dry brush (with a nylon brush) to remove the “grit” but intentionally do not take it down to bare copper as it is my understanding that leaving a bit of carbon is desirable.

I run a bronze bore brush on my drill into the neck. One low speed pass and done. I don’t know if it’s better or worse than any other process but I haven’t seen any negative to speak of. Maybe I’m doing it all wrong.

I am the guy who asked about non-toxic "homebrew" formulas for cleaning built up carbon deposits - inside the neck of brass. I am a novice hand loader so I have lots left to learn :) I inherited some older , well used brass that might be "work hardened" = varying degrees of brittleness, the carbon buildup appears to be almost "baked on" after many uses. "Work hardening" can also occur when brass is set back to the original factory COL with a full length die set after every use, when fired in a long throat / freebore chamber = lots of stretching. Some guys trim brass length back to factory COL after every use - the wall thickness of the neck gets thinner after each trim, because of stretching. Small cracks can appear on work hardened brass during shooting, resizing and seating - visual inspection should be done , after each step. Easier to observe small cracks from the inside of brass with a clean neck. There is a potential for the carbon buildup of crud to fill a hairline crack from the inside, when the bullet is seated. It wouldn't be visible until the crack reaches the outside of the neck. One guy on a forum used a hawkeye boroscope on 308 brass and he estimated .2 grains of capacity was lost on the inside with well baked on carbon crud. It doesn't seem like a lot but for one who works up to a maximum load , that may result in a stiff bolt lift due to a potential overpressure. Brass that weighs significantly more often requires reduced powder loads. Norma mentions in their hand load book , 300wm - two different production runs : one for heavier brass with less volume and lighter brass with more volume. Powder loads are different for the heavier (270gr) and lighter brass(215gr) !!!

https://gundigest.com/more/how-to/br...breaking-point
Usually you will find that when a cartridge has become too brittle to withstand that reworking, it will develop a hairline crack in the case mouth, either at the edge of the case mouth, or just below it.

Some guys mention on other forums - they use ultra sonic cleaners or ss pins = brass comes out sparkling clean inside / out, seating bullets become very smooth and consistent. A cleaner inside neck may lower the possibility of bullet runout during seating. :reading:

I find wet tumbling removes all or most of the carbon on the inside of the neck. Stainless steel pins get used here.

cleaning
 

I use a nylon brush with light lubricant to brush the inside of the neck before resizing. I usea a Hornady SONIC cleaner to clean my brass after it's been resized. This process removes the small amount of lubricant used in the resizing process along with carbon. I use an air compressor to blow residue moisture out of the brass and place the brass into the oven for a quick dry. Then it goes into the tumbler with crushed walnut for a polishing.

For a while, before filling my case with powder, I was dipping my necks into DRY GRAPHITE LUBE POWDER because I read that the Sonic cleaning process polishes the inside of the necks too much. For no reason, other then laziness have stopped doing this STEP.

I have done it both ways, cleaned to bare in my ss tumbler or leaving the carbon. On target rounds I leave the carbon, after sizing I just use some paper towel and wipe out the neck this leaves the carbon and likely just a hint of case lube. Bullet seating feels very consistent this way.
When I run cases through the ss pins the resistance seating feels slightly off case to case. That said I dont see much difference in 100 yard groups, the es does seem slightly higher on my cleaned brass but with small samples (5-10 shots) those numbers dont mean much. Sounds like a good test to run, 10 shots at 300y cleaned/non-cleaned and see what the results look like.

Interesting differences in responses. I suspect the “best” practice could be supported by LongBomber’s suggestion of actual testing for consistency...by comparing groups and velocities.
I recall settling on the practice of dry brushing after reading (and being convinced) that a little bit of evenly distributed carbon inside the neck promoted a consistent release. Wish I could remember the source and go back to it, but...
It makes sense to me, that a very light coat of lube, regardless of type, would be conducive to consistent bullet seating and release. When I was using conventional sizer dies with an expander button, I would dry brush and apply lube with a q-tip before resizing. The “brush” was to remove crud and the lube was to make sure the button did not bind and possibly pull the neck out of line. I then wiped the inside of the neck with rolled up Kleenex to remove most of the lube. (Obviously, some remains.). Now that I remove expander buttons, I just brush as the lube is not required.)
After reloading thousands of bullets, one develops a “feel” to the resistance encountered during seating. If one feels different, it will probably perform differently.
It seems to me that seating into a bare/dry neck would increase the neck tension (effect)?

I forgot to mention the "smooth and consistent" seating part still requires some type of lube. I will be using Redding's Imperial brand of dry neck lube w/application media - I wont be skipping that important part :) And will also be trying: http://www.redding-reloading.com/onl...case-lubricant

Some guys who use ultra sonic cleaners ,ss pins or a wet tumbler mention it is easier to notice small cracks and other defects with very clean brass. The carbon crud buildup can sometimes make it harder to spot worn out brass.

Sonic cleaner
 

Here's my method that works for me.

(Cheap Amazon 3.5l sonic cleaner)

1.De-cap all brass....rifle and pistol.
2.In sonic cleaner and 7/8ths warm water, 1 tea spoon dish soap and 1/8th white vinegar.
3. Do 3, 5 minute cycles.
4.dry brass
5. Tumble brass in crushed walnut. With nufinish car polish.

No carbon, crazy high polish that leaves a slick feel to the brass. In most cases I don't need to use any resizing lube.

Also sonic cleaner, cheap from amazon. I dont remember which size brookfield cleaner i have but i can do 145 brass in the dish. Mine is deep enough i can stand my 308 cases neck pointed down and all the debris falls out. Resized, and trimmed. I use a primer pocket cleaner before which deals with enough of the carbon in the primer pocket. I do 2 batches of water for 8 minutes with a squirt of dish soap. 2x8 minutes 50% vinegar/water, 2x8 minutes 1 tsp baking soda, 2x8 minutes fresh water. At the end I have to q-tip the water out of the primer pockets as the surface tension in the small spot takes forever to dry. Then lay on a towel for a day to dry. Not a spec of carbon left anywhere at the end of it all.