I was at a gun store this morning and while talking to an employee I was told that to get the best bang, meaning more fire from the primer, all the way to the powder was to slightly enlarge the flash hole. While this does sound like it could work, I am doubtful of it benefit. I can understand if there is a blockage, but just enlarging the hole doesn't seem like it would do much. If it matters we were talking about 45 ACP and 40 S&W for regular shooting not competition shooting. So for all of you have been reloading for a while, does that pass any common sense test, or was the guy hoping to get a new buyer of brass after I make mine unusable? Thanks

There is nothing wrong with uniforming the flash hole. Benchrest shooters always prep the brass this way. However, that only increases the flash hole a very small amount. Enlarging the flash hole will definitely increase the back pressure on the slide. In fact, flash holes are usually enlarged when shooting wax bullets in a revolver but they are never used for regular loads. Why not use a slightly heavier powder charge? Since handguns use a relatively small powder charge the cost difference has to be almost nill. I wouldn't do it!

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Dick

DON'T DO THAT!!! If you check with any competent reloading authority they will tell you enlarging the flash holes is DANGEROUS. Uniforming the primer pocket does just that, makes the primer pocket uniform it does nothing to the flash hole. Uniforming a primer pocket is like blue printing an engine, make everything fit as it was designed. You can debur the the inside of the flash hole with the proper tool for more uniform ignition but on the average handgun cartridge this is not needed unless you're building super accurate target loads.

If you need more fire from the primer get a hotter primer don't mess with 25,000 to 60,000 psi.

Rant over, Pecos

Enlarging the flash hole does put more fire on the powder, which in turn raises the maximum pressure and in high pressure cartridges this can be disasterous. Reloading data is for cases with the normal size flash holes and any alteration will make all your printed data incorrect.

Unfortunately this is old "Everybody knows" information. Not that I am suggesting anyone enlarge flash holes, I am not, there is simply no rational reason to do this with standard primers.

What I am saying is that with the advent of the so-called "Non-Toxic" or "Lead Free" primers the manufacturers have enlarged the flash holes in ammunition they load with these primers as a way to improve reliability if ignition. They had found that ammunition was not as reliable with standard sized flash holes.

I have yet to see any warning in any reloading manual, or article in any magazine, indicating that use of standard primers and loads need to be adjusted in any way when reloading these NT cases. If anyone reading this has seen any such warning I would appreciate being informed of this! Publication, date of publication, page, etc to document this please, not "I think I saw it in (insert publication name) a few months ago".

But, to the OP. Based on many years of observation the average gun store employee is not to be trusted, period. While there are exceptions, the average employee, and often the owner, has little practical experience and is not qualified to give expert advice. This is particularly true when it comes to reloading. If there were any benefit to be gained this advice would be widely known, and the reloading manuals would make mention of doing this.

Pecos Bill - I wasn't talking about uniforming the primer pocket. Sinclair, K&M, and others make flash hole uniformers. They have a drill bit to uniform the flash hole and they debur the flash hole on the inside. I shot competitive benchrest for several years and everyone uniformed the flash hole -- not enlarged it.

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Dick

WOW, that was quick. I was thinking that if a larger flash hole worked better then the manufacturers would be doing it. I had not thought about the better burn causing that much more pressure. I am glad that I asked before making the flash hole bigger. Thanks for the good advice.

Spend your time reloading and not messing with the uniformity of your brass - unless you are shooting a benchrest rifle. You will never know the difference in a handgun.

There is no ballistic benefit to enlarging the flash hole, but the ammo factories have gone on record saying the enlarged flash hole does not cause any problems, and that the "green" ammo with enlarged flash holes is fine for reloading.

I uniform flash holes and deburr my brass when it's new or once-fired, then shoot it until it wears out or splits. In thirty years, I also have yet to see any need to trim pistol brass. But I don't shoot max loads, either. Might be a correlation.

Think of the flash hole size like the jet in a carburator. A bigger hole would allow more pressure/gas flow to the primer pocket , causing high pressure signs at best , or blown primers at worst.

I've been reloading various ammos (handgun, rifle, shotgun) since the mid-'70s and have never bothered to "uniform" or deburr a primer hole. In that time I've had one misfires--a dud primer--, and a fizzle--a rain-soaked shotshell. I've never had any noticeable evidence that a shot was off because of a primer hole issue. If it caused any accuracy difference, those dead gophers and rock chucks 200-300 yards away didn't know it either.

While ultra-precision target shooters may uniform and debur a case as a matter of consistancy, for the run-of-the-mill practice or range round it's not worth the time or effort. But, if you have the time on your hands, have at it.

As for enlarging the size? Don't mess with what's worked for years!

some manufactures do do it. i have been reloading for 40+ years and have saw it done on factory brass. one that comes to mind was speer lawman ammo in the 70s they were quite large. but it is not dangerous to do so, but i see no advantage to it.

Look in any reputable loading source you have that lists the cases they used to get their data, then look for the paragraph that says something like, 'if you use any components other than what we used, start at the minimum load, or reduce by a given percentage, and work your way up'. There is a whole list of things that if changed will cause higher pressures that most reloaders ignore because the increases usually aren't that great. But if you are loading high pressure, near max., loads, or unwittingly toss in several things that all increase a little, you need to know what you are doing.

How many here inspect their range pick-up brass to make sure the previous shooter didn't drill them out to shoot wax bullets or some kind of shot loads? How many here that never trim their handgun brass also don't bother to check their range pick-up brass to make sure it wasn't trimmed extra short before they found it? How many here didn't know the brass they picked up took a small primer until they crushed a large one trying to seat it?

You don't enlarge for the sake of enlarging. The question is whether the hole is already up to SAAMI specs. If it is, leave it alone. There is no advantage to enlarging, but as already mentioned above, there may be a downside.

And as Jellybean says, check your range pickup brass. Don't just start loading it. Consider the possibility that the guy who left it there is also a reloader. And his rule is that after 15 reloads, its useful life is over and he lets it lie. Don't use maximum loads with range pickup brass, and be VERY careful buying brass at gun shows, that great dumping ground for all things bad, broken, bogus, and defective.

I have run into some unusually small flash holes. I don't bother to enlarge them, but keep the cases together for casual target shooting. I have yet to see a "small" hole cause an ignition problem with the relatively fast pistol powders most of us use.

I shot some Speer factory loads in .45 ACP, with Gold Dot bullets. Upon decapping the cases, I noticed the flash holes were much larger than normal. I contacted Speer about the "reloadability" of this brass and they said that it is completely safe to reload. I've loaded that batch of brass quite a few times, without problem.

You are reading way to much into this generic statement. This is known as a "Disclaimer". It is intended to absolve the publisher and component manufacturer of any liability as a result of a reloader deviating from the letter of the load recommendation if something untoward occurs.

In essence, all it means is "If anything bad happens 'We told you so'"! This has been around as long as loading manuals have been published. It is on a par with "Do not use reloaded ammunition in your (insert brand name) firearm. Such ammunition is known to cause firearm damage and personal injury".

Read the post above by Mike_in_VA concerning his conversation with Speer. Remember that is the same Speer which manufactures bullets and publishes reloading manuals. If anyone had an interest in giving accurate information they do. If Speer's ballistics lab had noted any reason to be concerned about the safety of using standard data and components in cartridges cases of their manufacture you can be assured they would have published a very specific warning such as, "WARNING: Do not use this data if loading Speer cases headstamped NT" They do not.

My original challenge stands. If you can cite a specific warning about reloading any brand of cartridge case with large flash holes originally loaded with NT primers I would appreciate seeing the citation.

Perhaps, after you have been reloading for over 50 years and something around 1 million rounds loaded, and probably well over 30,000 experimentally loaded rounds chronographed, you will have a better understanding how reloading really works and what makes a significant difference when making changes. Most of the "common knowledge" warnings about component changes date back to the days of smokeless powder and black powder primers, solid-head and so-called balloon-head cases, etc. In those days there were a multitude of significant variables, not minuscule ones such as we deal with today. Old wives tales die extremely hard!

Please excuse my ignorance here, but I have no experience with Speers NT ammo. Does every caliber have a larger flash hole, or just the .45 ACP that uses the small primer instead of the large one regular cases use?

The reason I'm asking is, while looking at Speer #14, page 966, I noticed a paragraph stating that several .45 auto cartridges using non toxic loads have small primer pockets for the lead free priming. They state that there are no safety hazards using the data printed in the manual and that a small primer should ignite them alright, but they will produce less pressure...avoid using mixed primer sizes if loading for accuracy.

Larger flash holes would make sense, since pressure is an important requirement for ignition with smokeless powder.

I may only have 30 years of handloading under my belt, but I have seen a lot of guys with more gray wiskers than me standing at the range with a shocked look on their faces and holding a broken piece of scrap metal in their hands.

To the OP. I noticed some talk around the 'net about enlarging flash holes, and it seems to be centered around the .45-70 cartridge, and using black powder. Speer was doing testing to see if they should try and develope a special primer for black powder rifle cartridges for the growing sport of using them in competition. They noted in their 14th manual that one thing they looked at, after they were almost out of brass, was enlarging the flash hole to equal the total volume of the original black powder cartridges, which had two flash holes. The test only consisted of a comparison between 10 original cases and 10 altered cases, in which they found more consistency in the altered cases.

Where I have seen this is in the instructions for Speer plastic bullets for use in the 45 ACP. In the instructions it is stated to enlarge the flash holes to eliminate primer set back but to mark these cases so as not to use them with powder. I can't give you chapter and verse but I refer you to Speer.

The op asked about enlarging the flash hole my post was an attempt to keep him from doing so based on information from Speer. Uniforming the primer pockets and deburing the flash holes, if done correctly, should not enlarge the flash hole and is a valid and good practice for match ammo.

As an aside I frequent several gun shops in my area and I find the average employee to be knowledgeable and honest enough to find the answer to questions when and if they don't know. I don't know where you shop but if the average LGS owner in your area has no knowledge of what he sells I'd find some where else to shop. Sweeping comments such as this are painful to read.

Pecos

"Average" gun shop employees can vary quite a bit, depending where you are. I've heard a lot of unmitigated B-S from behind gun counters, and I've heard good, solid counsel regarding guns and reloading, too. It's not like you can tell much about the employees from the appearance of the storefront.

The term "gun shop commando" has been around for a long time, and isn't about to leave our lexicon anytime soon.

I'm with Alk8944, disclaimers are one thing, but don't read too much into them.

There is a big difference between "disclaimers" and "valid safety concerns". It would be nice to write off everything you don't want to believe for the sake of an argument on a forum by calling them "old wives tales", but it doesn't work that way. Most reloading manuals do not go into internal ballistics because it is more than most handloaders care to hear, and adds a lot onto the cost of publishing a simple loading manual.

I'm not going to reread every book I've ever read because of this discussion, so I looked at the ones that had an index in the back of the book. They are older books and I'm sure those that want to disagree will dismiss them on that point, but I don't really care.

Naramore and Sharpe both stated that flash holes are determined by the factories based on the primers that the cases were intended to use and should not be enlarged. Sharpe noted that he had a ballistics lab do a test using .270 Winchester brass, comparing the factory size of .08" to enlarged samples with .101" flash holes. The average velocity increased 69 fps, and the average pressure increased 9000 pounds. This was using Hi-Vel #2 powder and non-corrosive primers. This is similar to what other books have said about larger flash holes, and the outcome of huge pressure increases with little velocity increases happens with a lot of the old wives tales too.

I'm not trying to change anyones mind about what they think, just saying to be careful where you get your info from, wether it be a gun store or the internet.

I am not into experimentation with cartridge cases, I only to examine for defects and reload them. My question is how do you examine the case to ascertain if the flash hole has been reamed or enlarged? Could you take a case from a known non-modified case and caliber and gauge it against cases in question?

Wow, what terrible advice. It can be done, but it is caliber & powder specific. Avoid gun shop employee advice. In 40yrs of shooting & reloading, I have never net a gun shop employee that really knew anything.

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NRA Cert. Inst. IDPA CSO