Steel Pin Tumbler and Flash Hole

[lp6]

Has anyone noticed that a steel pin media tumble does away with the need to deburr a flash hole? Looking at the opening with my Teslong it looks like all burrs are gone once I tumble.

 

[Dusty Stevens]

Has anyone noticed that a steel pin media tumble does away with the need to deburr a flash hole? Looking at the opening with my Teslong it looks like all burrs are gone once I tumble.

I debur all mine anyway but id suspect the pins would iron any burs out real nicely

 

[RustyInBend]

Steel pins are a messy PITA ... quit using them. Wet-tumbling with a good cleaning solution (I use the Frankford Arsenal cleaning packets) is way easier, less mess, and does a great job. I only deburr flash holes on brand new brass.

 

[dellet]

Honestly, you're more likely to need to do something with the flash hole after tumbling in steel pins than not.

If it will knock the burrs off, it will peen the edges of the hole closed.

 

[Ned Ludd]

SS pins do not cause peening sufficient to close the flash hole. Not even close. I've used SS pins for years and never seen any obvious signs of peening around the flash hole. If they smooth the flash hole edges out a bit, it's so minor you can hardly see it. Peening around the case mouth when using SS pins is a slightly different story. You can readily see the effect, although my understanding is that at least part of that effect is caused by the cases tumbling against one another, not the SS pins themselves. Obviously, the SS pins would have better access to the area around the case mouth as compared to the region around the flash hole at the bottom of the primer pocket or the inside of the case. Nonetheless, the way to minimize peening is to reduce tumbling time. In my hands, 30-45 minutes tumbling is more than sufficient to get the cases clean without heavy peening around the case mouth. If there's any remaining carbon around the bottom edges of the primer pocket, it can easily be removed with a primer pocket uniforming tool. I address flash hole burrs, etc., one time only on the virgin brass before it is ever fired. I have not found it necessary to do anything to the flash holes on subsequent firings.

 

[dellet]

SS pins do not cause peening sufficient to close the flash hole. Not even close. I've used SS pins for years and never seen any obvious signs of peening around the flash hole. If they smooth the flash hole edges out a bit, it's so minor you can hardly see it. Peening around the case mouth when using SS pins is a slightly different story. You can readily see the effect, although my understanding is that at least part of that effect is caused by the cases tumbling against one another, not the SS pins themselves. Obviously, the SS pins would have better access to the area around the case mouth as compared to the region around the flash hole at the bottom of the primer pocket or the inside of the case. Nonetheless, the way to minimize peening is to reduce tumbling time. In my hands, 30-45 minutes tumbling is more than sufficient to get the cases clean without heavy peening around the case mouth. If there's any remaining carbon around the bottom edges of the primer pocket, it can easily be removed with a primer pocket uniforming tool. I address flash hole burrs, etc., one time only on the virgin brass before it is ever fired. I have not found it necessary to do anything to the flash holes on subsequent firings.

I would agree on cases that have already had the burrs removed from the flash hole.

The OP suggests tumbling to remove the burrs.
I wouldn't count on that.

 

[RegionRat]

In development, production, and machining, hard media tumbling is often used as a deburring method.

It takes some testing, trial & error to get the desired results. YMMV

 

[lp6]

I tumble to clean the burs where an observation.