Deburring flash hole... Worth it?

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IALoder

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I just finished up deburring the flash holes on about 140 pcs of Hornady 6.5 Creedmoor brass, and the whole time I was doing it, I was wondering...does this really make a difference? I deburr the flash holes on all my "target shooting" and hunting brass just in case. Once it's been done, it's done, so I don't mind doing it. But have shot some consistently great groups with just sized/trimmed LC .223 brass and PPU .308 brass that I didn't deburr the flash Holes on. So what say you guys? Does it make a difference or no? Is it worth it to you?
 
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The idea that a consistent flash hole will help give consistent ignition seems sound. The truth is,there are not many rifles that are able to show a difference in groups by uniforming the flash holes. But many,myself included,do the task anyway,either out of OCD,or because it give a measure of confidence.
 
Not everything shows on paper as an improvement sometimes its a matter of not shooting big groups by having that one unexplained flyer. IMHO It comes down to desire, are you willing to leave no stone unturned? If so then definitely its worth your time no matter how trivial.
 
I had a guy tell me that "you don't know what you don't know" when it came to reloading and accuracy. What he meant was that, when stuff goes south, if you haven't done all the brass prep (rifle anyway), then you're alone out in the dark. Another told me that "there is no such thing as overkill".

New cases get flash holes gently reamed. Flash holes are punched after all. I've been kinda amazed at how much crap comes out.
 
I do all my rifle brass, especially Lake city brass that I have swaged to get the crimp out. It's surprising how many burrs get smashed over the flash hole from the inside during swageing.
 
I recall an article in the benchrest journal Precision Shooting a few decades back in which Creighton Audette (iirc) undertook some fairly extensive testing and found that for extremely accurate rifles, flash hole deburring might have made a slight difference, sometimes. I believe his conclusion was that with some cases in some rifles there may have been a statistical difference, and in other cases and rifles, it made no change. (I think there was even a situation where accuracy worsened just slightly, but was dismissed as noise in the data.)

The takeaway, I think, was that in the case of a top-notch custom rifle, with everything else massaged to perfection, it might help and can't hurt. I personally haven't been involved in that kind of situation since about 1990, so am not entirely sure where my flash hole deburring tool is at the moment.
 
I recall an article in the benchrest journal Precision Shooting a few decades back in which Creighton Audette (iirc) undertook some fairly extensive testing and found that for extremely accurate rifles, flash hole deburring might have made a slight difference, sometimes. I believe his conclusion was that with some cases in some rifles there may have been a statistical difference, and in other cases and rifles, it made no change. (I think there was even a situation where accuracy worsened just slightly, but was dismissed as noise in the data.)

The takeaway, I think, was that in the case of a top-notch custom rifle, with everything else massaged to perfection, it might help and can't hurt. I personally haven't been involved in that kind of situation since about 1990, so am not entirely sure where my flash hole deburring tool is at the moment.

Audette cost me a lot of money, by the way!! And, that's exactly why I said "gently".
 
I deburred the flash hole on my Service Rifle ammunition. I can't say I saw an improvement, but what the heck, it could not hurt and it was a one time thing with new cases. With a properly adjusted flash hole deburring tool, it does not take much time.

Otherwise, I do not bother.
 
I think that deburring the flash hole really depends on what your goals for your ammo are. If you are a precision shooter or maybe a long range shooter and you are trying to get the most accuracy possible out of every round it could be a variable that you want to consider or at least experiment with. For me at this point it isn't something I do but I am happy getting MOA out of my handloads.
 
I’ve got an RCBS case prep center so it’s no big deal, I do them all! Does it make a difference? It sure does if you are swaging primer pocket crimps on Military brass. Deburr first, before swaging.
 
I deburred the flash hole on my Service Rifle ammunition. I can't say I saw an improvement, but what the heck, it could not hurt and it was a one time thing with new cases. With a properly adjusted flash hole deburring tool, it does not take much time.

Otherwise, I do not bother.

You must have read Zediker's "The Competitive AR15" too. He recommended doing it there. I bought one, and do my .223 cases. I seriously doubt that it matters.
 
The answer is often it depends. What are you expectations, is your rifle capable of shooting the difference, and are you capable ?

For me loading target ammo or hunting ammo I never do it. My equipment and the guy behind the trigger probably cannot shoot the difference.

Your results and needs may be different. It definitely could make a difference, and is one more thing to make your ammo more consistent between rounds.

-Jeff
 
I just finished up deburring the flash holes on about 140 pcs of Hornady 6.5 Creedmoor brass, and the whole time I was doing it, I was wondering...does this really make a difference?

Like lots of stuff, it depends. My suggestion would be to take say 20-40 cases, all from the same lot and do half of them, then load up and shoot all of them the same. Then you can see if you can tell any difference, if you can see any difference at all, then decide if the extra work is worth what that difference is.

Some people just like work or things to look pretty, kind of like rubbing a cloth all over their car, others just want to win the race and concentrate only on things that matter to achieve that goal. Doesn’t make either wrong or right, just have different aims and goals to achieve.
 
I used to do it until I tested the difference in the accuracy, SD and ES between deburred and not deburred Lapua brass

I don’t bother with deburring anymore ;)
 
I used to do it until I tested the difference in the accuracy, SD and ES between deburred and not deburred Lapua brass

I don’t bother with deburring anymore ;)
Quality brass is the equalizer in that scenario. I would have a lot less faith on budget brass...
 
I just finished up deburring the flash holes on about 140 pcs of Hornady 6.5 Creedmoor brass, and the whole time I was doing it, I was wondering...does this really make a difference? I deburr the flash holes on all my "target shooting" and hunting brass just in case. Once it's been done, it's done, so I don't mind doing it. But have shot some consistently great groups with just sized/trimmed LC .223 brass and PPU .308 brass that I didn't deburr the flash Holes on. So what say you guys? Does it make a difference or no? Is it worth it to you?

I don't know, I've never cleaned flash holes since 1975 or so.

Have a blessed day,

Leon
 
Not everything shows on paper as an improvement sometimes its a matter of not shooting big groups by having that one unexplained flyer.
This is where I am.
An offset flash hole will give flyers. De-burring finds offset flash holes and they get trashed.
I trim pistol brass once time also. So I obviously don't mind wasting time.
 
Does it hurt to de-burr flashholes? No. Does it take a lot of extra time if you use a case prep machine anyway? No. Is there a value in easing your mind about one in a hundred that might have a serious deflector burr in its flashhole that just happens to come up affecting an otherwise wonderful group in competition? That's called Murphy's Law.....if it is possible for something to go wrong it probably will. Making the odds of that as small as possible, is better IMO than ignoring the possible.

I don't hunt anymore, and I don't compete anymore....but I still make my ammo the best I know how.....just habit.
 
Like lots of stuff, it depends. My suggestion would be to take say 20-40 cases, all from the same lot and do half of them, then load up and shoot all of them the same. Then you can see if you can tell any difference, if you can see any difference at all, then decide if the extra work is worth what that difference is.

Some people just like work or things to look pretty, kind of like rubbing a cloth all over their car, others just want to win the race and concentrate only on things that matter to achieve that goal. Doesn’t make either wrong or right, just have different aims and goals to achieve.

That's exactly what I wanted to write.
Not much work, easy to do and a quick result.
 
I did it on my 6PPC cases for Benchrest, I don't do it for my 6 Dasher that shoots under 1/2" all day long unless I screw up, sometimes much smaller than that. That said, in PRS we are not shooting from super stable positions like a Benchrest rifle, so it's doubtful it would help.
 
I do it on all brass I get for my bench rifles. I've run across several that the flashing was sticking up so High I had a difficult time getting the tool into flash hole. Premium brass has not been any problem, it's the low cost every day commercial brass that has the problem. Some are worst than others but 98% are probably not bad enough to make any difference. It just those with the massive fisher that cause all the problems.
 
So what I'm getting is a resounding "yes, no, maybe so". I feel the same way. Maybe, maybe not. But for my hunting and target ammo, I have no problem doing it. As @osprey176 said, I think I do it because it gives me a measure of confidence. The consistent flame/powder ignition makes sense as well! It doesn't take long with a case prep station, and I don't mind doing it. I feel that my group sizes are limited by me, not the rifle or "burred" flash holes. It's been very interested to me on what everyone has to say about it!
 
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