Tool to Uniform the Flash Hole

[Sooner04]

Hello all wise reloaders from a somewhat still new reloader,3 years now) --

I have a question about uniforming the flash hole on my brass and finding a tool to do so.

Of course I have a tool to debur the inside of a flash hole if I use brass other than Norma or Lapua but I don't ever see where it has changed the diameter of the flash hole itself as I am sure it is designed not to do.

To use an example let's say for 6.5-284 cases and .3006 cases will the hole sizes be different between the two for Norma, Lapua or Winchester brass?

And are there any easy tools to use that are out there to buy to uniform the flash hole for each if you were to need a different diameter?

Thanks for the help; if my question doesn't make total sense let me apologize in advance and I will try to ask it again!!

sooner04

 

[jb1000br]

http://www.6mmbr.com/catalog/item/1433308/900728.htm

 

[tenring]

I just read JB's link regarding the K&M flash hole reamer - http://www.6mmbr.com/catalog/item/1433308/900728.htm

Recently, I discovered that the 6mm BR Lapua brass, does in fact have .059 flash holes - but why??? I used my Kinneman 6ppc flash hole reamer measuring .062, on the 6BR brass, and tightened my groups. Just finished opening 100 of them. I will continue to do so. So why does Lapua not open them to .062 at the factory? Are there any authoritive articles on the subject?? Anyone else tried this??

 

[Forum Boss]

I just read JB's link regarding the K&M flash hole reamer - http://www.6mmbr.com/catalog/item/1433308/900728.htm

Recently, I discovered that the 6mm BR Lapua brass, does in fact have .059 flash holes - but why??? I used my Kinneman 6ppc flash hole reamer measuring .062, on the 6BR brass, and tightened my groups. Just finished opening 100 of them. I will continue to do so. So why does Lapua not open them to .062 at the factory? Are there any authoritive articles on the subject?? Anyone else tried this??

The flash-holes are spec'd at the Lapua factory to 1.5 mm . That is how it has always been.

1.5 mm = .059"

When you order a PPC or 6BR die from Redding they should provide a .057" diameter decapping pin.

Most of the "PPC" flash-hole tools do, indeed, increase the size of the hole slightly. Some guys think that's a good thing. When I used a K&M tool on my 6BR flashholes, the tool reamed them to about .066. That's too much. I got a little more velocity with the same load, but pressures increased and SD went up. Now I don't touch the flash-holes on 6BR brass except to inspect if there is some obvious flaw.

Unless you have a K&M cutting bit turned down in size, the most precise tool for minimal flash-hole reaming is the Sinclair 07-3000 reamer, which reams the flash-hole from the outside.

"This tool was designed specifically to ream small flash holes,.060) to exactly .0625". The handloader addresses two issues when using this tool; 1) It enlarges the holes just enough for the die maker's decapping pins to go through without getting stuck, 2) Each case will have exactly the same size flash hole insuring uniform ignition. This three piece tool has a stainless steel guide that centers the reamer in the primer pocket from the outside, a stainless steel handle which is knurled for easy turning, and a straight-fluted .0625" reamer. Originally designed for use with BR and PPC cases, but we are seeing more cases from Europe show up with the smaller flash holes."

NOTE, many top-level PPC shooters have been reaming their flashholes to .620-.625" for years, and they shoot great groups. Whether it's necessary or not is another story.