Help 30x47 Lapua Flash Hole

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When opening the flash holes on the 30x47 Lapua, is the interior of the flash hole (meaning interior of the case) chamfered or is the hole opened up all the way through to the primer pocket and how would one measure the size of the hole or the inside case chamfered hole size?
Any and all answers will be appreciated.
 
flash hole drills..

Just use a drill bit the size you want .....the hole might be a cupla thou. bigger ..but you will have acomplished what you are after....use a flash hole de-burr tool on the inside of the case to champfer (sp)the hole a lil and it will be fine...it is not complicated or difficult....Roger
PS>..most flash hole de-burr tools are a drill that cleans out the flash hole...just use the large size one and it will drill out the hole and champfer all at the same time!!!
 
Flashole

So does the deburring tool need to go all the way through the bottom of the case?
 
flashhole

Yes, I know this but does the deburing tool protrude all the way through from the interior of the flash hole to open the entire hole or just chamfer the inside to make it like a cone shape inside the case?
 
Just remove the burr on the inside. Most of us just spin the tool in our fingers a few twists......you'll feel the "click" go away as the burr is removed. DO NOT remove any more mat'l than necessary to take the burr off. DO NOT remove material from the inside of the case head, because you'll (dangerously) weaken it.

-Dave-:)
 
Floyd: Some flash hole uniformers have a bevel built in that slightly chamfers the inside floor of the case head.... a cross sectional view of the flash hole chamfer would look like this: \ / :D


Most flash hole tools will have the flash hole cutting part of the tool all the way through the flash hole when they start to cut the chamfer. I've never been able to see that chamfering the inside many any difference at all but I still do it just to make sure there's no ragged edges...which would probably be gone the first time you lit up a case full of powder. ;)
 
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what are we doing here?

My understanding of flash holes on ppc and 6.5x47 Lapua brass is that they have a smaller diameter flash hole. The small diameter is thought to enhance the uniformity of the primer flash. My Sinclair deburing tool has a flash hole uniforming bit that does an excellent job on my 223 mil brass of deburring and uniforming the size of flash hole. However, I would never use it to enlarge diameter of the flash hole of the aforementioned Lapua brass.
 
You need another tool. All they are is a center drill. Go to MSC or McMaster Carr and order the appropriate one. Bore a hole in a rod and press it in.
Butch
 
Butch?

Is it common to enlarge these small flash holes? I thought they should remain small.
 
hbr

It is not unheard of for hbr shooters to use 6/47 lapua to make 30/47 brass. I know it is short but it does work. My experience is that a 5/64 drill bit makes a .078 flash hole and I get better accuracy than with a small primer flashhole. The hornady 6.5 Creedmoor and 30TC use the large primer because their engineers found the large primer more accurate in the larger volumne case. A larger flashhole is the next best thing.
 
from my experience

phonso said:
It is not unheard of for hbr shooters to use 6/47 lapua to make 30/47 brass. I know it is short but it does work. My experience is that a 5/64 drill bit makes a .078 flash hole and I get better accuracy than with a small primer flashhole. The hornady 6.5 Creedmoor and 30TC use the large primer because their engineers found the large primer more accurate in the larger volumne case. A larger flashhole is the next best thing.
Click to expand...

The size quoted here is about right. More fire is better from what I have observed. I drilled mine out to .072 but a few thou larger isn't a very big deal, IMHO. I agree on the large primers. The only thing potentially gained with the small primer case is tougher primer pockets. There ain't no magic. That said, I have around 600 of them in stock! ;)
 
So, on a 30x47 Lapua case made from 6.5x47 Lapua one enlarges the diameter of the flash hole to approx. .072 inside to outside,then chamfers the flash hole inside the case.
If so do the cases need to be trimmed to lenght prior to fireforming so that the chamfer depth is a consistant depth in each and every case?
 
I made my flashole deburring tool with a c'drill as suggested by Butch. I pressed it into a piece of drill rod that had a hole that was a tad too deep. I then machined away the drill rod so that only a small portion of the angle surface was exposed. The outer part became a sleeve that controls depth.
Works for me.

Jay, Idaho
 
Chamfer depth

For beautiful consistant chamfer depth try the K&M tool, best $20 you can spend!
 
Drill bits to enlarge flasholes can make strange holes, not always the same size. Pin reamers are available from MSC in any decimal size you want. I
routinely use an .064 on Lapua ppc cases. This makes a near perfect size
hole and eliminates stuck pins. Judging from how they cut, I make the assumption that they are not exactly the same coming out of the box anyways. Drill bits in brass can and do have strange personalities and I
avoid them for flasholes.
 
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