A trick for deburring flash holes

[EDG]

Remington rifle cases have the flash hole punched and it leaves a raised burr that looks like a king's crown on the inside of the case. The jagged edges of the burr make a flash hole deburring tool bounce up and down rather than cut. Cutting away the burr can be time consuming without this little trick.

Take a Lee or equivalent hand depriming punch. Using an 8 oz dead blow hammer put the punch into the case and give it a whack to flatten the burr against the inside of the case head. This flat burr will no longer have the raised jagged edges. The flash hole deburring tool will easily cut the flattened burr at the insection of the hole.
The majority of the burr will then just fall off and can be shaken or washed out of the case. I find removing the burrs much easier.

[daengmei]

Sounds like it works, but I noticed on some 45acp cases that I had the deprimer rod too deep and it actually moved the case web? downward (towards the rim) a bit. Don't know that it changed anything or not but is this possible using the punch...will it matter if it does move that area?

[Hardcast416taylor]

RCBS used to make a very good de-burring tool for their hand or case prep station machine. They changed the design a few years back and now it does just a fair job. I got ahold of a Sinclair de-burring rod, threaded it to fit on the RCBS prep machine and now am back to being a happy de-burring critter! Your trick of mashing the burr down sounds like a last ditch measure step. I have not had to resort to the hammer and punch method yet. If it works for you, then Gods speed to you.Robert

[fastfire]

I use the lyman but put it in a drill.

[deepwater]

With a K&M hand turned flash hole remover, I start turning with very little downward pressure. When the first few burrs are cut more pressure can be applied until finished. This eliminates extra steps and really does not add that much extra time.

When I first used the K&M tool, I quickly got blisters on my thumb and finger from the corners of the hex tool body. I ground them down (radius-ed) and it has been fine for hundreds of cases. In a conversation with K&M about this, the owner was in complete denial that I could have a problem! Excuse me for the injuries your product caused.

deepwater

[EDG]

This is not a last ditch measure. It is more of a very best practice. Perhaps it is hard to imagine how efficient it is unless you actually do it yourself.

I have both Lyman and RCBS flash hole deburring tools that are maybe 15 years old. They were both manufactured from common center drills. As such the center drills only have 2 cutting edges and tend to bounce on the large funnel shaped burrs. It it only takes 2 or 3 extra seconds to flatten the burr when decapping once fired brass. With new unfired brass it might take 4 or 5 seconds per case. With the burr bent over and flattened the entire burr does not have to be turned into chips. Only the thin burr material has to be cut at the edge of the flash hole. Then the rest will fall out.

[Newtire]

This is not a last ditch measure. It is more of a very best practice. Perhaps it is hard to imagine how efficient it is unless you actually do it yourself.

I have both Lyman and RCBS flash hole deburring tools that are maybe 15 years old. They were both manufactured from common center drills. As such the center drills only have 2 cutting edges and tend to bounce on the large funnel shaped burrs. It it only takes 2 or 3 extra seconds to flatten the burr when decapping once fired brass. With new unfired brass it might take 4 or 5 seconds per case. With the burr bent over and flattened the entire burr does not have to be turned into chips. Only the thin burr material has to be cut at the edge of the flash hole. Then the rest will fall out.Sounds great EDG. Just a light whack it would seem all yu would need do it too since it's only brass. Great tip! Thanks!

[EddieNFL]

With a K&M hand turned flash hole remover, I start turning with very little downward pressure. When the first few burrs are cut more pressure can be applied until finished. This eliminates extra steps and really does not add that much extra time.

When I first used the K&M tool, I quickly got blisters on my thumb and finger from the corners of the hex tool body. I ground them down (radius-ed) and it has been fine for hundreds of cases. In a conversation with K&M about this, the owner was in complete denial that I could have a problem! Excuse me for the injuries your product caused.

deepwater

I chuck mine in a drill. No blisters, no double handling cases.

[deepwater]

I did that and the cutter got dull quickly.
K&M states that they should not be used under power. Maybe I ran it too fast.

deepwater

[fastfire]

I've been using a Lyman for 10+ years in a cordless drill and done many many thousands, still works good.

[EddieNFL]

Variable speed drill is the trick. I use my drill press to turn pocket uniformers and a small 12V driver to run the Wilson trimmers. I'm lazy. Haven't ruined a cutter, yet...but it's only been 40 years.

[mold maker]

While I'm with you on making everything as consistent as possible, is deburring the flash hole really worth the effort on anything other than competition brass? I'd think if it really made a difference the brass Mfg would have done it already. I do think making the flash hole the same size between brands, and/or removing a burr that is left in front of (covering) the hole might effect it. However, clearing burrs can be over done.

[gkainz]

one would think someone could fashion some kind of shoulder on a decapper pin that would decap and mash the flash hole in one step?

[captaint]

mold maker - Someone has - Norma and Lapua. No burrs. Of course we pay for that !! I used to do my "accuracy" rifle brass. I've never done handgun brass flash holes ...

[Smoke4320]

deburring the flash hole sure makes a difference with subsonic rifle rds ..and also in rifle rds intended on 500+ yds .. Used to do 1000 yd comps and it would definitely show up in group size ..
sonic rifle rds less than 400yds not so much really .. but hey you only have to do it once anyway ..

[Dale in Louisiana]

I just open my drill bit index and pick one that's slightly smaller than the neck diameter. Using my fingers, I stick the bit into the case, spin it a couple of times with my hands, and <bingo>! the burrs are gone. High speed steel drill bit and brass case? I should be able to do this for years.

The primer hole centers the bit for this move.

dale in Louisiana

[GoodOlBoy]

Well fellers I suppose there is a solution for everything, and I am glad to read this one if I ever need it. That being said I am on the side of mold maker on this one. I just don't see the darned point. I have shot long range, short range, and everything in between. Guess I just must have been lucky.

GoodOlBoy

[GrantA]

I haven't used it much but working up a subsonic 223 load (trailboss and Barnes 85gr matchburners) drove me crazy til I added the deburrer (RCBS) to my case prep station. It definitely made a difference!