Shallow Angle Deburring Tools

[Krogen]

I use the typical Forster inside/outside deburring tool. It usually takes several turns to remove the burr. In doing so, it removes a significant amount of brass. Once the inside and outside burrs are removed, the case mouth often has a near knife edge.

I see plenty of narrow angle (28 deg or 30 deg) inside deburring tools. These are used for VLD or boat tail bullets. Seems like that would work well on the inside without removing a lot of brass. I have not seen an outside narrow angle deburring tool. Anybody know of a source?

 

[rcmodel]

Sum Ting Wong!
(sorry, I am watching an old Kung Fu movie as we speak.)

If you are getting knife edge case mouths after chamfering & deburring with a standard double-end tool?

You are WAY Overdoing it!

A single twist inside and out with a sharp deburring tool should be all that is needed to break the sharp 90 degree edges.

And that's all you should be trying to do.

rc

 

[Krogen]

Thanks, RC. That was my thought as well. However, unless I go 2-3 turns, I can still feel the burr with my fingernail.

I would agree. Something is amiss.

I guess I should add that if I trim the case mouths, the burr is very thin and sharp. In that case, a single turn with a deburring tool works great. I only see the issue with new and untrimmed cases.

 

[gamestalker]

There are a couple things that are causing this apparent issue. When I first started using my RCBS / L.E. Wilson tool I bought over 30 yrs. ago, I had brass mouths I could shave with, they was sharp, and I in fact cut myself more than once on them. I just couldn't seem to get a smooth surface on the outside of the mouth, yet the inside of the mouth was always smooth, no lip at all, didn't make any sense.

I tried different tools, yet the problem still presented. But after some time and lots of practice, I figured out what I was doing wrong, and what else was going on, as follows:

If you use a super light touch, and at super slow speed with the drill, it won't leave that little lip your getting. What's happening, the brass is getting piled up above shave line. In a way, when you ream and chamfer brass, your almost literally just knocking the lip off left by the tool, plus a small finishing surface accomplished by the sharp cutting edge if used correctly. And if the lip your referring to is on the inside, your most certainly using too much pressure.

Something else I discovered with many common factory once fired head stamps, and that can fool you into thinking there is still a lip there, is the crimp line left by the factory process. IMO, the worst of them is Winchester, but I've seen this on numerous factory once fired brass. After trimming, the crimp groove is often real close to the rim of the case mouth. So this makes it appear by feel, that there is still a lip, when in fact it's a crimp groove right near rim of the case mouth that your feeling. And it can often be felt on the inside of the mouth also. Short of turning the necks, there isn't much you can do to completely remove it, and even then, some are likely deeper than turning will totally remove. Usually by the 3rd or 4th reloading the brass will stretch enough that it gets trimmed off, most of it anyway, more if my loads are warm enough.

Have you tried seating your bullets with less material removed? And if so, are the bullets seating ok, no shaving?

GS

 

[Krogen]

Good ideas, gamestalker. I've been putting up with this since I started handloading in the 80's. Like you, I've tried various tools and just came to the conclusion "that's the way it is." Inside deburring is not a problem; the mouths clean up nicely. It's always the outside. Bullets seat well without shaving.

I currently use a Forster DBT bench-mount base. I have a goofy technique that is effective in removing the outside burr. It's easier to do than describe. As I rotate the handle with my right hand, I use my left hand to move the case off-axis in a circular motion. The case moves as if on the surface of a cone. That way the cutting angle varies and I get a smooth, rounded surface. A lot of fiddling if you ask me!

After processing a bunch of cases last night, I was browsing Sinclair's website and noted the VLD deburring tools. If only somebody made a similar one for the outside of the case my issues would be cured, I thought.

Thanks for the suggestion. It never occurred to me to use a lighter touch! Being malleable, it makes sense that I'm simply displacing brass rather than cutting it. I will try using a lighter touch this afternoon.

 

[gamestalker]

I'm glad I could help.

I agree, it is odd that the inside doesn't develop that ridge though? I think it has something to do with the deep depression on the outside of brass that has been previously factory loaded. The damage to the mouth is usually significantly more pronounced on the outside.

GS

 

[FROGO207]

I do both operations at once but separately rather than using a combo tool. I use a pair of RCBS handheld combo chamfer tools. They are made by L E Wilson. One chucked by the pin in the center into a low speed battery drill to inside chamfer the case necks and the other one picked up after and twisted by hand to outside chamfer. I also find when doing the outside if I wobble the tool in my hand as it is turned there is no "lip" left behind. A dull tool will also leave a lip as well. I may replace the inside chamfer with a VLD reamer in the future.

 

[Jesse Heywood]

I'm in the middle of making .22 TCM brass and have a similar problem. I am using the Wilson chamfer tool and with shaky hands have trouble holding the tool straight, especially on the outside. Any suggestions?

 

[gamestalker]

With shaky hands, sorry, but I've not had that problem as yet. But maybe you could find a way to lay the drill on it's side, maybe prop it on something so it's just off the surface of the bench, that way you could rest your hand against the surface of the bench?

GS

 

[FROGO207]

For post #8 I hold the tool in my right hand and roll it between my thumb and index finger while pressing the brass against the tool with my left hand and do the same sort of thing with it (left), only roll the brass the opposite direction. I will wobble the tool as I do it to get rid of the lip. This works well for me. About one turn of the brass using finger pressure does it with little effort.

 

[Jesse Heywood]

Thanks, FROGO207. Sat in my chair straddling a trash bucket. Forearms resting on my thighs. Your tip doing the counter-rotation worked. My shakes supplied the wobble.

 

[FROGO207]

Great!

 

[mdi]

Brass can be pretty soft and if a tool isn't quite sharp enough, it can push up a "burr". Cleaning up a case mouth, deburring, is different than chamfering (applying a taper inside the case mouth). Deburring only removes the burr and mebbe .003"-.005" of base metal. Personally I don't run any outside tools on any of my brass unless there's a burr from trimming that I cn see from arm's length...

 

[mdi]

OOPS!