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Primer Flash Hole Deburring

DaveB

DaveB

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Sep 3, 2008
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Location
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Just got the Midsouth Shooters flyer on various shooting stuff they want to sell you.

What stuck in my mind is the picture of a piece of brass with a hole cut in it showing the state of the flash hole. They want to sell you a flash hole deburr tool which I understand as they are in business to do these kind of things.

Question is, does anyone do this? is there any perceptible accuracy improvement? Can you tell you have done anything at all? Note: The author says Lapua brass is teh only brass drilled not punched and doesn't need deburring.
 
I would say that the thin burrs on the inside of the flash hole would burn away after a shot or two anyway. If I was concerned about it I would just take a #1 center drill and give it a couple turns by hand and be done with it.
 
I deburr mine, but I don't to the extent shown in the picture. I just clean up the edge. I haven't done a before/after test, but it puts my mind at ease. You only have to do it once.
 
infoman jr.":3u72y65j said:
I deburr mine, but I don't to the extent shown in the picture. I just clean up the edge. I haven't done a before/after test, but it puts my mind at ease. You only have to do it once.
Click to expand...

This. I also use a carbide primer pocket cleaner/cutter. The reason is because it makes me feel better. Good therapy and gives me confidence. Doubt it makes any difference at all except in my mind.
 
So, what I am reading is since we cannot see inside the brass we should take appropriate steps to uniform the brass to reduce possible manufacturer errors.

I have seen oblong primer flash holes (used to have pics someplace) and off-center ones.

The likelihood something is wrong where I can't see is probably slim, BUT, what did SnowWolfe say? it makes me feel better.

I am in agreement.

Think I will slide by Harbor freight and get a drill press. Order the tool from Midsouth. Develop a system i can do in my sleep and get going. I like to feel better.
 
DaveB":1samzp75 said:
So, what I am reading is since we cannot see inside the brass we should take appropriate steps to uniform the brass to reduce possible manufacturer errors.

I have seen oblong primer flash holes (used to have pics someplace) and off-center ones.

The likelihood something is wrong where I can't see is probably slim, BUT, what did SnowWolfe say? it makes me feel better.

I am in agreement.

Think I will slide by Harbor freight and get a drill press. Order the tool from Midsouth. Develop a system i can do in my sleep and get going. I like to feel better.
Click to expand...

I use the Lyman debur tool on mine. It has a sliding collar you can set to the depth you want to chamfer. I don't do it on 223 casings but always on all of my lr casings. With the Lyman it only take a few twists and is easy enough to do without a drill press. I also uniform primer pocket depth and do it with a Lyman tool in a cordless drill.
 
I do it for my varmint rifles but honestly I'd say you'd be mighty hard pressed to ever see a measurable difference in group size because of it. I have a hand tool that I don't recall the manufacture of. I got it when getting set up for 22 CHeetah loading years ago and from that point on used it for the other 22's also - 221, 22-250 and 220 Swift. It does make you feel better to know you have the fewest variations possible in your brass.
 
The SAMMI standard flash hole is .080" You can use a #2 center drill which has a .078" pilot on the end to keep it centered in the flash hole. Use it in a drill or simply hold in a vise or with vise grips, insert it into the flash hole and rotate the case with your fingers. The following link is for a 6" long #2 center drill...Perfect for the job. With a slightly chamfered hole, the primer flame is allowed to propagate into the powder column evenly at a 60 degree angle 360 degrees around the flash hole. Burrs can cause flame propagation to be uneven or even one-sided.

https://www.amazon.com/HHIP-5000-0031-C ... nter+drill
 
Lapua brass with small primers have smaller flash holes that are 1.5mm which is .059" ,, if using that brass dont use the tools for normal brass with the .080 flash holes,,
 
All my brass get the primer hole deburred. (I just use the regular RCBS with the correct collet.) Sometimes, you can feel a pretty good chunk of metal get cut out of there, and see how big it was when you dump it out.
You can knock out a large quantity while watching TV.
 
I was at the NRA AM in Atlanta last W/E and stopped by the Redding Reloading booth and talked to Robin S. he's a very experienced shooting and reloader. I asked him "what's the next step in improving my reloads?" I explained that I wasn't a comp shooter but I wanted to improve my hunting loads to extend my hunting range. More specifically I asked which should I do first, trim necks or work on primer pockets and flask holes. With no hesitation on his part "Flash holes and primer pocket" he then proceeded to explain why.

So flash hole tools (1) and primer pocket uni-former tools (2) are on my wish list.
 

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