How important is primer pocket/flash hole prep?

[Blackhawk]

Theres my post already said I uniform primer pockets and deburr flash holes both the first time on new brass. Uniformity is the name of the reloading game. I like the little bevel it puts on the inside of the flash hole, it makes the ignition more consistant and wider IMHO. You see that bevel on ML'er breech plugs a lot. Weight sorting, reducing runout, all small uniforming tricks, figure it all adds up to something noticeable at the end of the job.

By God Almighty, there really are people out there who are very intuitive and passionate, as well as knowledgeable about handloading.
Sometimes you just can not stress the point enough concerning uniformity, and consistency with regards toward handloading ammunition.!
INHO Your statement reaffirms that point ! Kudos to you!!!

 

[Shootin4fun]

OCW / flat node outweighs (pun intended) many factors.

 

[JAYgs8163]

Here are some pics of brass after fired one time. Top with flash hole NOT being uniformed bottom was uniformed. I copied these from a prior thread I was involved in. It does make a difference for those wanting the best results.

 

[Opa-lopa]

I have a pretty large body of data that says there's NO benefit. 30+ 20 shot groups with, 30+ without. Wouldn't be the first place I'd look to tighten up groups.

 

[jdyoung]

I look at it as eliminating factors that affect ignition consistancy and in the long run accuracy. No matter what brand it is, one can ever tell which factors in the manufacturing process can result in inconsistency in case weight , primer pocket depth, flash holes burrs , etc . A dull tool, people sick, change in personnel , not enough coffee breaks , you name it. ( I started my Son of prepping 100 rounds of brass for his 6mm when he was 14 , primer pocket depth & flash hole deburr) .

 

[338 dude]

In my own A/B tests, I have not seen deburring make a noticeable difference on Fed or Remington brass. It may make more of a difference with fast powders than slow; that would be another test. Lapua which does not need deburring is of course more consistent in every way so that's not a direct comparison. Finding your OCW is where it's at, and will overcome some other variations in the load. I have loads that produce the same ES/SD while varying primer mfg. and brass mfg. Single or low double digit SDs. My statistical samples are usually 5 shot strings. But if you are really serious about this, then you might just want to skip all this and just buy Lapua, who do not punch, but rather drill the hole.

I

used to think exactly as you do until yesterday after much controversy on several threads in the past someone said why do we not ask so I did hear is the result

 

[DJ Fergus]

Among the Lapua, nosler, Norma & alpha brass I've had, I never saw a need for it. I personally never noticed a difference in it when I did deburr fed & Remington brass but I'm not saying that someone else didn't see a difference. It's definitely good to be flexible and have an open mind when trouble shooting. I have disproved my own thoughts many times.

 

[Ts3]

Sacriledge!!
Seriously though, I've always deburred mine, then stopped and saw great groups without. Lately watched the video where Gavin is interviewing Bryan litz and Bryan said that he doesnt based on testing showing it doesn't do any good. He is a x ring guy though, not a BR guy. Try 10 rounds of each for yourself and see if it helps

Yes, watch this video.

 

[bigbull]

Am I missing out on a very important practice?

I do it usually on new brass if it is not already proper, I check every case.
At the end of the day there is no down side to this step.
At the end of the day you must also own an accurate rifle and be capable of shooting accurately enough to see a difference........................... if there is one.
Are you short of time, why do you question this step?

 

[MNbogboy]

Well, I uniform the primer pockets because I like the way it makes them look. Nice and shiny. Sometimes, however the primer pocket is too deep for the cutter to reach, in which case I grab my RCBS primer pocket cleaning tool and get the rest of the soot out. I also have the Lyman "Screwdriver" flash hole de-burring tool and I use that too but I don't mess around with the set screw cone thingy on it, I just do it by feel. I do think that deburring the flashhole in this method makes the flame from the primer ignition propagate more evenly around the circumference of the flash hole, making for more even ignition of the charge. Do I have hard data that it improves my group size? No. But I feel good about it. I guess it's kind of like driving a Prius, but for the record, I do NOT drive one.

Driving a Prius is not normally a status symbol in the conservative world. They are usually driven by an elitist that snubs the affordable vehicles of the working man.
Have you ever seen a dead deer tied to one?

 

[Arkansasdad]

In my reloading experiences thus far I've never messed around with deburring flash holes, specially cleaning or uniforming or in any way correcting primer pockets or flash holes...

Am I missing out on a very important practice? How big of a difference does this make for es numbers and accuracy? Please share if you do this, and please I'd love to see some "before and after" data regarding consistency of performance.

thanks.

The military personnel that shoot at Perry shoot Lake City Match or PRC match. I have inspect

In my reloading experiences thus far I've never messed around with deburring flash holes, specially cleaning or uniforming or in any way correcting primer pockets or flash holes...

Am I missing out on a very important practice? How big of a difference does this make for es numbers and accuracy? Please share if you do this, and please I'd love to see some "before and after" data regarding consistency of performance.

thanks.

Military personnel that shoot at Perry shoot Lake City Match or PRC Match. I have inspected it and as far as the brass is concerned cannot see any extra work being done on the brass. Once an armorer told me the only difference between standard ammo and match was the powder was different and there are some extra steps taken to make every charge dropped falls within a tighter tolerance as far as grains. The brass is the same as you can buy off the shelf from your reload supplier, no special work done on the brass. All SOP operators shoot pretty much the same ammo right out of the box, I have never known one to reload, they just shoot and most are better on their worst day than I will be on my best. Just something to think about...

 

[Will Gray]

If you are a world class target shooter, EVERYTHING matters, but if you need something around 1" accuracy for hunting not much matters. Case brand seems to matter a bit as different brands may have slightly different volume. When I find a good load, I just duplicate it every time. I don't worry much about powder weight, weighing one in ten to be sure nothing has slipped but if level looks the same in all the cases, it will be fine. All of my rifles shoot better than I can and I shoot pretty well...

 

[BoomWop]

I uniform and deburr after the first fireforming shot. I get better sd's. I've been tuning firing pin height, spring weight, and preload since I started shooting. My grandfather taught me this in such a funny way it stuck. That makes no sense if you don't have uniform pockets.

I don't dispute your results but do you think your improvement could be attributed to case volume consistency after fireforming? That said I DO deburr and uniform, at least until I started using Peterson brass. The pockets on these are too tight for my tool.

 

[MNbogboy]

Deburring flash holes may only make a difference on target one shot in a thousand.
That's why I do it.