I've purchased the K&M 0.062" Uniformer/Debur tool to clean up the flash hole in my 6.5x47L brass. Has a consensus been reached as to whether it does more harm than good? I'm running my loads on the hot side of things. Thanks.
Flash Hole Uniformer 6.5x47
- Thread starter Mooster1223
- Start date
Does it actually raise the pressure or does it allow the pressure to exert more force on the primer, therefore indicating higher pressure?
Don't touch Lapua brass. One of the things you're paying extra for is a drilled flash hole.
Enlarging primer pocket increases internal pressure?
Yes and no. Consider the flash hole in brass similar to a nozzle on a garden hose.
The smaller hole in the Lapua brass can, depending on primer used, keep a long hot flame burning into the powder. Long flame = more powder igniting at same time = more consistent ignition (in theory). Powder and bullet momentum is not initiated by primer ignition, but by powder ignition
Enlarging the hole is similar to that garden hose nozzle....the spray opens up and close powder ignites first and the powder further in the case starts to push out with the bullet and it takes a little longer to feel the heat. Wide open primer hole, like a wide open nozzle on the hose, allows all the pressure to escape at once into the case. The old gallery loads with plastic bullets had wide open primer holes allowed the pressure to blow the bullet out of the chamber, but did not keep hot flame on base of the bullet. Bullets lasted quite a few firings.
Yes and no. Consider the flash hole in brass similar to a nozzle on a garden hose.
The smaller hole in the Lapua brass can, depending on primer used, keep a long hot flame burning into the powder. Long flame = more powder igniting at same time = more consistent ignition (in theory). Powder and bullet momentum is not initiated by primer ignition, but by powder ignition
Enlarging the hole is similar to that garden hose nozzle....the spray opens up and close powder ignites first and the powder further in the case starts to push out with the bullet and it takes a little longer to feel the heat. Wide open primer hole, like a wide open nozzle on the hose, allows all the pressure to escape at once into the case. The old gallery loads with plastic bullets had wide open primer holes allowed the pressure to blow the bullet out of the chamber, but did not keep hot flame on base of the bullet. Bullets lasted quite a few firings.
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I presume the recommendation to leave them alone goes for my 223 Lapua brass as well?
The uniformer is either 1) a drill bit or 2) a reamer. Neither does anything a drill bit at Lapua doesn't.
By all means go with what works for you but again, .005" out of .0625" is inconsequential to the end result for shooting long range targets in my experience. The folks who use the larger primer pocket Lapua brass are able to get their loads to work well. They just need to be a bit more finicky with their primer choice.
The flash hole in the Lapua .223 Match brass is a tad larger than the .308 Palma (SRP) flash holes from my measurements. I left them alone.
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