Its another urban myth that is fading away except among the terminally anal. Any "boogers" that may be present go away with the first firing which should be a fire forming shot anyway.

I'm going to disagree with most on this post. I have read most of the better reloading books - including books written by the likes of Sinclair, Zediker and Tubbs. Everyone of them states that deburring the flasholes is one of the easiest things to do to improve the consistency and accuracy of your rounds. I have seen the difference first hand with my reloads. I will say that the importance of the improvement depends on what you are shooting. It helped most of my rifles tighten up groups anywhere from .25" to about .5"). This makes quite a difference when shooting targets or small varmints out at 300 yards. However it may not make that much difference if you are shooting a .338 at an Elk at 100 yards. I have seen enough of an improvement that I do it religiously to all of my brass regardless of purpose or caliber. One reason that Norma and Lapua are considered to have superior brass to American brass is that their flasholes are drilled and not punched - hence no burrs. Good Shooting!

Mule Skinner:

Ditto.

And most old-time medical books suggest that a transfusion of cow's milk into your blood system will make you feel better, and if that doesn't work, then try rubbing chicken fat under your arms.

Let us not get too polarized on this issue, please. The science and available, verifiable evidence will not support either side.

You gotta understand the history of this thing to make any sense of it. I shot benchrest 30 years ago, and it was a day when deburring and flash-hole uniforming were very experimental. Mostly used by die-hard cranks, etc. Not everybody would agree that primer pocket uniforming was useful, either.

It is just that the benchresters started eliminating any possible variable in order to eliminate fliers and shrink groups. They left no stone unturned, either. That means that some things caught on that might not have otherwise. I suspect that if I had a batch of really bad cases or one with a big burr, I would deburr the flash-hole, too.

Do these things, as they have documented proof of usefulness at, say, 0.5" (0.5 moa) or less.

1-Every case should have the primer pocket uniformed. That along with match grade primers.
2-Size as little as the situation will allow for good reliability. Not much for bench use: F.L. for field use.
3-Buy good brass. Don't waste your time weighing it, either. If a particular piece of brass gives you fliers, pitch it and get another. Lapua and Norma will solve a lot of problems.
4-Get a tubing micrometer and measure case necks. If they are much out of round, outside neck turn or get another lot. At that, do not outside neck turn too much, it just increases slop in the neck otherwise.
5-Get a set of sizing ring type sizer dies, one in neck only and one for F.L. Throw away the inside expander button and only use the sizing ring. Buy several rings so that you can vary the size and get it right. I have 50 or so neck bushings. You can get the Lee Collett die instead. It loads straight ammo, but be aware that they are not perfect.
6-Get a straight line seater, like the Forster or Redding with the micrometer dial and keep track of settings.

Hope that helps.

Trust me, if it would reduce my groups by a half inch, I'd be doing it. Over the years, I have tried most of the various tricks that were guarenteed to change a rifle into a one holer. Some help; others don't. I tried to go at it with my eyes open however and, instead of blindly following the herd, keep the good stuff and past on the superflous.

I have often said, if the winner of a stool shooter contest was chewing grape gum, the next week the whole line would be chomping away. And shortly, there would be weighty tomes discussing which brand of gum was the best.

For what its worth, if you believe in it, do it. It doesn't hurt and it keeps you off the street and outa bars. Also, knock yourself out paying three or four times the price for Lapua brass so you won't have to pay a couple of bucks for the little dealy booper thingy and take the moment of time to chamfer the flash holes. Reloading is really about what makes you happy.

Well, you see it's like this...


5-shots at 200-yards.
Firearm: Ruger 77V in .22-250 Remington
Optics: Leupold 4-12x optics
Case: Remington
Primer: Remington 9-1/2
Powder: 38.4 grains of H-380
Bullet: Sierra 52 grain Hollow Point Boat Tail

As you can see I do not use "premium brass", and I can tell you upfront that I do not drill flash holes, I do not have a single tool on my bench with "Sinclair" etched on it, I do not measure case thickness, I have found absolutely no advantage to "match primers", I do not use collet dies, and I use no other special dies.

The above example is not a fluke either...I have several targets posted on my website with similar results...

Hello,All,
I'll agree that most of the flashhole reaming does me very little good,beyond just confidence building.But I am sure that the occasional"hanging chad'that gets removed,does a lot of good.
Frank

I believe that for small cap cases like the Hornet, it's worth the effort. Doesn't really take that long to deburr flash holes anyways.


Tim

There is a difference between "deburring a flash hole" and "reaming a flash hole". These are also different from "uniforming primer pockets".