K&M Flash Hole Uniformer tool works great

[mchees1]

Prepping some new brass today and doing the flash holes. Since I now have a Teslong, I decided to take a couple of pics of the before and after. K&M tool does a very nice job. Surprising how much material is removed. The last picture is the pile of shavings from 150 pieces. A little tedious to do but only have to do it once. One less thing to worry about when trying for consistency.

 

[Mikemci]

I also use the K&M tool.
Most of the brass removal is from the corners of the pocket. They always have a radius to them. I also use it to clean out the carbon after each firing, works great.

 

[Dusty Stevens]

That brass looks like it needs more than a primer uniformer. What brand is it?

 

[mchees1]

It is some Hornady. The pics are of the inside of the case flash hole using the K&M flash hole uniformer.

 

[Dusty Stevens]

If thats a chamfer on the inside thats not very conducive to accuracy. Needs to be as square as possible- like as if the flash hole was drilled with a nice clean hole and no countersink. Here is a bulletin with more at the bottom that may help

http://bulletin.accurateshooter.com...ix-clearing-flash-hole-obstructions-in-brass/

 

[Joe Maisto]

If thats a chamfer on the inside thats not very conducive to accuracy. Needs to be as square as possible- like as if the flash hole was drilled with a nice clean hole and no countersink. Here is a bulletin with more at the bottom that may help

http://bulletin.accurateshooter.com...ix-clearing-flash-hole-obstructions-in-brass/

My K&M flash hole reamer By Ken Merkle is as slick as they come, ( in my opinion). It goes in from the cartridge mouth, has a .062 drill bit machined into it, removes any burrs or residue from said flash hole, and bottoms out when clean and done. Wish I knew more about putting pics on here...
Mr. Merkle did his homework on everything he created.

 

[mchees1]

If thats a chamfer on the inside thats not very conducive to accuracy. Needs to be as square as possible- like as if the flash hole was drilled with a nice clean hole and no countersink. Here is a bulletin with more at the bottom that may help

http://bulletin.accurateshooter.com...ix-clearing-flash-hole-obstructions-in-brass/

What can I say. The chamfer is the way K&M designed it. I agree with Joe Maisto. But to each their own.

 

[Kracken McGraw]

What can I say. The chamfer is the way K&M designed it. I agree with Joe Maisto. But to each their own.

My Redding tool puts a chamfer on the hole too.

 

[oley55]

If thats a chamfer on the inside thats not very conducive to accuracy. Needs to be as square as possible- like as if the flash hole was drilled with a nice clean hole and no countersink. Here is a bulletin with more at the bottom that may help

http://bulletin.accurateshooter.com...ix-clearing-flash-hole-obstructions-in-brass/

Dusty, Based on the pics he posted I am not convinced there is any countersinking there. Those dang magnifying teslong images are really difficult to interpret. High spots look like low spots, lands look like grooves. Seriously, give those pics another closer look.

 

[memilanuk]

If thats a chamfer on the inside thats not very conducive to accuracy. Needs to be as square as possible- like as if the flash hole was drilled with a nice clean hole and no countersink. Here is a bulletin with more at the bottom that may help

Just for the sake of argument (it *is* still winter / off-season here!), why is that?

Coming from other 'hobbies', I've seen where it's been noted that you generally get better flow / less turbulence thru a bell-mouthed orifice, as opposed to a straight/square transition. Extending that logic, it seems that a bit of chamfer on the hole would aid in the primer flash penetration into the powder column, i.e. better ignition. Not saying that necessarily translates into real-world results in this particular application, but I'm not seeing anything at the bottom of that article other than links to essentially the same article, or portions thereof, reposted over the years.

 

[bozo699]

Looks like it did an excellent job to me I have both small and large primer uniformers from K&m and really like the job they do.
Wayne

 

[Baer45]

I love the way mine cut also...beats Sinclair for me

 

[Bill Norris]

Looks like it did an excellent job to me I have both small and large primer uniformers from K&m and really like the job they do.
Wayne

Yep. I use them on all my brass. From what I can see it appears that it does leave kind of an angle around the inside opening of the flash hole.

 

[Dusty Stevens]

Just for the sake of argument (it *is* still winter / off-season here!), why is that?

Coming from other 'hobbies', I've seen where it's been noted that you generally get better flow / less turbulence thru a bell-mouthed orifice, as opposed to a straight/square transition. Extending that logic, it seems that a bit of chamfer on the hole would aid in the primer flash penetration into the powder column, i.e. better ignition. Not saying that necessarily translates into real-world results in this particular application, but I'm not seeing anything at the bottom of that article other than links to essentially the same article, or portions thereof, reposted over the years.

Theres a difference in deburring and chamfering. If theres something in the hole it may need deburring not chamfering. Some of the top br shooters have done extensive testing on this, and still do test some of this type stuff in tunnels- im sure a search would turn up something- or maybe not. The best testers that can actually do it right dont talk much about their results (or even the tests for that matter). Basically the take away is dont touch a flash hole, but of course meaningful testing will give you the answer you need.

 

[JMayo]

I'll lightly spin New brass on a debur tool but other than that the pocket cleaner brush is the only thing that's gonna "grind" any brass at the pocket and that is gonna be as minimum as possible.
I've got brass with close to 30 firings. Pockets still just like the new brass except the primer holes are starting to get edgy. If I had "helped" them I think they would be all screwed up by now & garbage.
Each to his own.
Enjoy your toys ! That's why you bought em !

 

[hillbillydruggist]

Prepping some new brass today and doing the flash holes. Since I now have a Teslong, I decided to take a couple of pics of the before and after. K&M tool does a very nice job. Surprising how much material is removed. The last picture is the pile of shavings from 150 pieces. A little tedious to do but only have to do it once. One less thing to worry about when trying for consistency.

Man, I don't do this but I might start after seeing all those shavings