Match brass prep: flash hole deburring 

Hey John, you drew your powder really really low on the cartridge: I know you were maybe exaggerating for the sake of the diagram, but without talking about flashover, I think this diagram boarders on dangerous.

Hello John, thanks for video! I do mine as well and it nice to see the inside shot to see the finished work. Consistency is everything! Great job!

Thanks for the inside view of the brass. That helped. Didn't even think of using my bore scope to view inside the case.

Thanks again John. All your videos help me greatly.

John, Merry Christmas. I wish I could contact you personally but it is what it is. Because of your help progress is coming. Shot a .086 group today but not satisfied until it’s consistent. Good factory rifle from a well known maker but good brass and a little technique; barrel prep, brass prep, projectile consistency, etc. Blessings to you and your family.

Eye opening. I use one of the collet tools for deburring flash holes. But, I can see where you might be doing harm. Thanks for the video!

I have two wildcat pistols built for silhouette shooting, used Parma style Benchrest brass, and even if it was the best available at that time, the flash holes were erratic to be kind. Lyman has a similar tool, but multi caliber with an adjustable stop, that was used to deburr and slightly chamfer the inside of the hole. Your tool looks caliber or at least neck diameter specific, which looks light years better than my old one. Takes seconds, if only for peace of mind and possibly just possibly making everything possible similar, well worth the time.

The before and after in the case shots sold me. Very informative

Awesome explanation! The up close visual certainly helped. Thank you for that and merry Xmas!

After watching this video I did a test. I did 400 pieces of Hornady factory ammo brass I had been holding onto. I got 9.8 grains of brass chips and flakes from inside the brass just using this one tool. I inspected a lot of them with my borescope and it was amazing how well it cleaned up all the flash holes that desperately needed deburring as there were tons of burrs on most of those 400 pieces.

I’m glad to see an old benchrest technique is being used. The video technology today vs what Precision Shooting magazine and shooters news had , twenty plus years ago would have made more of an impact on shooters.

Thanks for sharing. Nice to see just what is going on with the primer holes after cleaning them up.

I've had a tool like this since 1983 when loading for IHMSA shooting 7TCU. If there is any doubt, it DOES make a big difference. My only quibble is the tools that index on the case mouth is too inconsistent between batches if you work on differing calibers. Do a batch of cases today, change calibers then next month if you need more cases you have to duplicate the first batch by feel and guess but no way to measure. Because of that I believe in the bushing style tool (sinclair generation II or the 21st century one). Personally, I have a precursor bushing style that has a plastic knob for hand turning (no longer sold I think). Works great even if you want to go crazy and debur 45acp or 9mm.

Consistent with reloads for consistent performance. Makes sense to me. Thanks for the information.

Hi John, I have been using this tool for over 2 years now and definitely agree that it makes a great job of consistently cutting and squaring up the flash holes , and like you said it only needs to be done once for the life of the brass , but there will always be people that say you don’t need to do that with brass such as Lapua but I beg to differ, glad you posted up a video too cheers all the best Gianni.

Huge difference will have to go and get the tool😁

I did some .223 Remington case-prep to zen-out yesterday and I remembered that I had one of these (which I'd bought on a whim) and decided to dig it out and use it. On some, but not all, the cases, I could definitely feel that it was doing SOMETHING. I think next time I'll lock the cases into my Lee case-trim chuck to get a better grip on them and hand-turn them counter to the tool, and compare the feel of what the tool is doing. Watched a few of your vids last night and subbed. I don't shoot anywhere near your level of accuracy (most of my centrefire shooting is pistol or milsurp for pleasure), but I'm finding it very informative.

I use a Lyman flash hole uniformer with the collar that is set for freshly trimmed cases. Once thing I find is the inside case base to case mouth length is not the same, even within a batch of same headstamps. The uniformer will definitely cut more brass from some cases than others, regardless of the amount of burr debris. An old timer told me to think of the flash hole the same as a fuel injector. Neither produces the consistent spray of fuel/flame it should when dirtied up. He made sense and once I began deburring flash holes, my groups improved.

Preparing brass is accomplished to maintain uniformity from shot to shot. 1. Uniform primer pocket 2. Uniform flash hole 3. Debut flash hole inside case

Looking at every detail is an F class shooters attention to Xs!!! Kudos

Nice talk. BTW, the brass you showed in your "before" example is way better than brass like we have to start with in XTC. For example, most batches of LC brass or commercial 223 brass will have far more serious flash that might interfere with ignition. Your pile of debris and chips after your batch is less than what might come out of just a few of the worst offenders. All of which is to say, it is better to have the right tool when you need it so you have the option if you want it. Merry Christmas and Happy New Year!!!

Wow that's a pretty big difference by the looks of it.

I do it with my brass, have the odd punchout still stuck in there, or a tearoff remnant that I can feel in there. For the time it takes and only having to do it once, it seems to be worth it to my mind.

It's punched from the bottom. That's why the inside of the case has the irregular hole. It breaks through from the bottom and the rough part is on the inside of the case. It's usually punched with the head stamp at the same time.

As far as consistency spend the $110 this tool is amazing. I wouldn't recommend this for bulk reloading. A properly sized end mill with or without a pilot, can clean up the internal area with a drill press and a proper shell houlder like the Forstner Case trim fixture PT1010. You don't get the consistency the 21st Century tool provides, its money well spent. For those bulk reloading maybe consider a $25 end mill in your drill press.

Thanks, gr8, informative and visual. I’m an addicted OCD reloader myself and often thought that my quest to consistent reloading has compensated for a lack of range time. One thing I’ve been wondering about is whether powder that enter the pimer and flash hole after reloading might equate to inconsistency. Surely this will happen to different amounts and degree. Ball powder more so compared to extruded powder I guess. Ammo being transported/stored in the vertical vs horizontal position. Vibration that over time might lead to compaction. No way that this potential space will be filled and compressed with a consistent amount of powder. Might this make a difference?? I know this comes down to splitting hair, but that’s what we do. I found some anecdotal information on the net of people seating primers through paper and using ‘flash hole wads’ to prevent this. More so with black powder rifles. Does anyone have more infomation or thoughts on this?

Great video.Im a new subscriber and was curious about the flash hole.Got lucky on this video after watching Erik Cortina .He recommend your channel

Been doing this for years, a cheap usb camera like a Teslong is good for this as using my $1500 bore scope for this is a risk. Some of these cases inside finish is poor, just buy better brass to start with like Lapua. I did a ballistic lab test on primers and that showed a big SD difference in primer makes and the best was not a bench rest type, but that will change batch to batch i think.

These little things add up that's why we do case processing.. Many trimmers, trim uneven with in +, - .005 around the same case. Why not do things the right way? Thank you for permoting doing things the right way; we need it. It is also challenges the manufactures when you bring things up.

Does flash hole concentricity matter? I just picked up some Aguila brass and all of the flash holes are clearly and visibly punched off-center. I don't even need to measure with dial calipers to see that all of this brass is off a good 1/32 of an inch. Should I reload these? How will this affect ES and SD?

Good Vid John

Preparing brass is accomplished to maintain uniformity from shot to shot.

You may be right, But the Lapua, Peterson, ADG etc brass has SO much better flash holes than the general cheap brass I don't even bother or think its worth it myself. If I was using Hornady ,Remington, Winchester, etc (cheaper brass) I would definately do it! Just look inside their brass compared to Lapua or other top brass. Its like night and day! Its good to have other opinions and folks trying new/old things tho. I would keep checking your ES/SDs and see if its any better than without doing it. In the end its what works for you. Evidently John believes in it so more power to him. Thanks for showing folks as usual!

great info, thank you very much

Hi John, luv your knowledge and insight. Does Peterson CNC their brass. I'm new to a lot of this and hearing about CNC'd brass is a first for me. Thanks!!

Nice video again. Cheers

great video!

For some of my hunting rifles, I've used poorer quality brass like Federal and substantially more burr debris compared to what you show with your quality Peterson brass. With virgin brass, do you also uniform the primer pockets?

What are your thoughts on chamfering the pocket side of the hole as well? The theory of forming a nozzel so the flame propogates as a jet into the powder

I would be interested in seeing a brass that was once fired and not cleaned up before and after. Makes sense that every little thing you can do to make the brass as consistent as possible would be better, especially at the level you're shooting.

I’m just wondering if chamfering the primer side of the flash hole would help also? I’ve never been that worried about flash holes but I’m just curious.

I still do mine

Yes, I think the proper tool makes a huge difference. Most flash hole tools will remove the burr, but the chamfer will be very inconsistent. It's a case of benchrest lore making it into to mainstream and the benefits get lost in translation.

Did you try the k&m one if so is that one good

Have you done any chronograph and/or accurracy tests with brass not uniformed, then the same brass uniformed to see if it really makes a difference? It makes sense to uniform the flash hole, but I am curious to know how much actual difference it makes.

What is the affect of drilling the flash hole a little larger? Why is it set as a specific size? I don't see in the SAAMI drawings where the flash hole size is specified, maybe it doesn't matter to a point-don't want to weaken the case head of course.

do you do this after every firing for brass or just once?

Computer analysis by another Bench Shooter suggests there is no difference?

You don’t believe a chamfer on the flash hole would promote a better more consistent burn of the powder? I found that trimming the case to minimum saami specs and deburring before uniforming the flash hole with a collet type tool, got the most consistent results. Burrs on flash holes are a variable. Get rid of them I say... Great before and after photos.

I had to check if this was an old April fools video. The amount sexual innuendos are intense lol. I can’t decided if it was intentional or not. Either way great video.

Cortina fully automated bullet pointing... you didn’t hear it from me. Maybe you can get him to automate deburing flash holes for you.

Getting rammed up the bottom is never a preferred technique

4:36 Amen brother

How does this impact deviation?

Why do you guys never mention Norma?

I find that my Lapua brass has pretty clean flash holes. Hornady not so much. Bryan Litz doesn’t believe flashhole deburring makes any difference....

well you ask how good this is working? I can tell you it works i used a carcano 6.5 i set up a box at 25 steps i hit target, i went to 50 yards shot a few shots and i set it aside yes a scout scoped rifle it was less then 1 moa i made the mount fit, i shimmed it with washers and glue! you ask why ( i drove a it to a gunsmith 100 miles away with proper mount and scope and need 4 holes drilled and taped i went back a month later not done i could not wait any more he said it was not a good shooting rifle) ??? if the guy in daily plaza had his ducks in a row would get same out come! sound or no sound! this was a chopped off one! i went threw ever 6.5 rifle i could put my hands on why you ask i cut lawn for a lady her dead husband worked under jfk had some to do with ag stuff farming secretary of ag under Jfk i went to 1000 yard shoot i heard same sound as tape on his murder! why after the med scoped me i could not do to much they forgot i was on blood thinner(big goof) ever since summer my life been upside down relation died his place was gone threw and set on fire! the day before i got there! i got back from 2 week stay at home order and the week one was done my neighbors though it was great time to pack up and move and not tell me or any one!! great right! how about 3 feet of snow in one night & then a 4 days to shovel out after restocked it all melted to 8-12 inches and ice all over ? some one in Pa rigged the election? some one mad?

I just want to get it in and start working it....

I find it hard to watch your videos with all of these ads mate.

Ha ha ... you said rammed up the bottom 🤪

Link is dead: 17 April 2024.

0:50 and 4:35. Sorry, I couldn’t help myself

He said it rammed in the bottom😂😂😂💀💀💀💀😳🤔

When no less than 4 different multi world record holders and HOF BR shooters going on record in multiple interviews state they have done countless hours of testing messing with flash holes and do not mess with them. It either has no effect or a negative effect. We are talking SR LR 100-1000 record holders. Some with direct access and sponsors by Lapua Vhit, Alpha, Peterson Berger, McMillian etc. So have you actually tested this and can see a statistically relevant positive effect or are you just once again doing something blindly just hoping it helps and because you are over thinking stressing and obsessing which is more about insecurity than anything else.

There were quite a few 'That's what she said' moments in this video.