How important is primer pocket/flash hole prep?

[Calvin45]

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.

 

[cape cove]

I don't do much primer pocket uniforming because most good brass are pretty good(Lapua etc) but I have noticed that, IMO, all brass should have their flash hole deburred and pockets cleaned. Leave no stone unturned if you are in pursuit of the best of accuracy. Some cases have a large burr on the inside of the flash hole that can affect how the primer ignites the powder thus affecting the ES. JMO

 

[Savage 12BVSS]

I don't do much primer pocket uniforming because most good brass are pretty good(Lapua etc) but I have noticed that, IMO, all brass should have their flash hole deburred and pockets cleaned. Leave no stone unturned if you are in pursuit of the best of accuracy. Some cases have a large burr on the inside of the flash hole that can affect how the primer ignites the powder thus affecting the ES. JMO

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.

 

[257Tony]

Maybe I shouldn't say this publicly, might get flogged... But I've never really done anything to mine, never felt like I was missing out.

 

[JMW67]

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.

I believe your brass is like the foundation for a house if you start with crap you very well may end up with crap so any prep work is worth the effort as most of it is a one time thing

 

[Sevy]

I do deburr the flash hole and uniform the primer pockets on new brass. I have no evidence that it makes a difference. But I have seen large burrs on the inside of the flash hole a couple times. I do it because why not, it only takes a couple extra seconds and I can't imagine it hurts anything as long as you don't screw it up somehow.

 

[imyourhuckleberry]

I've never done it other than cleaning or swaging if its crimped brass.

 

[milo-2]

I used to do it religiously, uniform, then use the uniformer to clean-scrape the carbon out. About 4 yrs ago or, all the new Norma and Lapua brass I was buying, I could not touch metal till 3 firings with the tool I had been using, I even bought a new uniformer from Brownell's that had an even shorter nub.
So I have not cleaned in quite some time and do not see any ill affects downrange.

 

[Mram10us]

Maybe I shouldn't say this publicly, might get flogged... But I've never really done anything to mine, never felt like I was missing out.

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

 

[milo-2]

Try 10 rounds of each for yourself and see if it helps

Bingo!

 

[Calvin45]

I do deburr the flash hole and uniform the primer pockets on new brass. I have no evidence that it makes a difference. But I have seen large burrs on the inside of the flash hole a couple times. I do it because why not, it only takes a couple extra seconds and I can't imagine it hurts anything as long as you don't screw it up somehow.

I have no doubt there'd be no detrimental effect in doing this sort of thing, just looking for some experiences confirming improvement with hard data. Thanks for the feedback. I do think I'll start doing this on that same basis, it can't make anything worse and just might make it better. On the flip side if we eliminate all possible culprits other than ourselves when the guns and ammo aren't shooting the way we want we might just be humbled a bit too much so maybe I'll keep leaving them alone! In all seriousness, what tools for these jobs would you all recommend?

 

[Mram10us]

On the flip side if we eliminate all possible culprits other than ourselves when the guns and ammo aren't shooting the way we want we might just be humbled a bit too much so maybe I'll keep leaving them alone!

I like to blame the action screw torque when I have a bad day. "This will stack em in one hole all day .... except when those darn action screws..."

 

[Liberator]

I believe it helps on the lower grade brass. My groups went from 1-1.25 down to .50-1.0 in. Mainly got rid of the odd flyer. Lapua and some of the higher grade brass probably wont see much difference. Saw just as much benefit when I started annealing the necks more often. JMO.

 

[captrjc]

I'm of the belief that the flash hole burr s will never be exactly the same as another. In the pursuit of consistency cleaning up the flash holes with some kind of redundancy keeps that pursuit on course.
The jury is out for me on primer pocket uniforming. I have batches with and without and I just am not that good a shooter to record a difference.