Flash hole deburring

[Badgersmilk]

You guys do it?

Some say it's unnecessary altogether.  I use a Lyman's deburring tool, but it leaves the chamfer it creates really choppy and uneven IMO.  Have you guys found anything thats doing a better job?

Before:


After depriming in the press, and deburring with the Lyman tool:


It does a good job trueing up the hole, but the chamfer is RUFF. 

[TAB]

I don't do it.


If I was going to do it, I'd most likly chuck it up in the drill press and use the postive stop.

[philw]

i don't yet

[ellis4538]

I shot NRA Highpower and never found it necessary.  Bench Rest shooters might or Die Hard Varminters might.

JMHO


Richard

[m25operator]

You put some good pics up, I think and apply, the primer hole de burr is a good idea, and makes sense, a deformed flash hole will effect perfect performance with a rifle,, does not apply with a handgun, unless, you are shooting extremely accuarate sports like Bullseye or IHmsa. Where a 1/2'' matters. If performance matters, do it.






























I

[Sponsor]

[rat31465]

For handguns No, don't waste your time...If you are talking about super accurate High Power Rifle or Benchrest Ammo....Yes by all means.

[tombogan03884]

I won't comment on whether or not it is needed, I'm not that deeply into reloading, or that experienced.
I will comment on the HOW though, If possible I would use a deburring tool, or countersink that had a "flatter " angle on it so that it removed the burr without removing so much material from the inside of the flash hole.
Maybe something like a long #1 or #2 center drill ?

[PegLeg45]

I don't do it.


If I was going to do it, I'd most likly chuck it up in the drill press and use the postive stop.

I knew a guy who shot in some big bullseye matches around the southeast and did it with his selected loads for competition. He also shot bench-rest too.
He only did it to his competition loads and he used the drill press with an extra fine grinding stone/bit normally used with a dremel tool. He built a jig using a shell holder for a reloader and set his stop at the right depth.

[rat31465]

Concerns about removing too much material are valid and good advice...However just as an FYI....All the quality Deburring tools I have used..such as Sinclair, Reddings and RCBS do have a collar/stop on them which is adjustable.
 
I also have an RCBS model which I chuck into a cordless drill if I am deburring alot of casings for a Prarie Dog/Varmint Rifle.

Reports I have read from those who spend more time researching the subject than I say a shallow radius or chamfer is preferable as it helps give the primers flash a more cetered and uniform cone of fire. 
Since flash holes are punched and not drilled, the excess material usually pushes over to one edge of the flash hole and deflects the primers flash off to the side otherwise. 
Velocity and pressure uniformity can be affected by this depending on powder type and even how it lays in the casing.

I can verify that the amount of material that falls from casings can be suprising.

I even uniform the primer pockets, size the casings and trim them all before sorting by weight...
Afterall Weight equals material equals volume.

[Tyler Durden]

No, not ever, on straight walled pistol brass.

on bottlenecked rifle cases, hmmn...uhh...jeesh.. 

for my AR and it's 3 gun competition ammo, NO!

but the next time I have my dremel out, I will cut off the case heads and snap a picture of the huge burr that punching that flashhole leaves behind.

I have to wonder effect does decapping the brass have on getting rid of the burr.