The importance of clean primer pockets

[Roonster]

Hi guys,

How important is it to have clean primer pickets? I’ve got some very experienced friends who say it is critical that the primer pockets are cleaned meticulously, and I have other equally experienced friends who say they don’t bother cleaning the pockets at all and just ‘whack another one in there…

 

[Will the chippy]

It matters if you think it matters. If you stress about the little details then it will matter. If your confident in your load and your technique then you'll rarely miss. A quick heart rate, heavy breathing, a bad rest, bad footing will make more of a difference.

 

[Malxwal]

Test it for yourself, see what effect it has on your SD ?

 

[enfieldspares]

It makes only one difference. That if the primer cup edge cannot seat hard up against the base of the primer pocket. If there is no fouling where the primer cup walls sit then there shouldn't be an issue. And where the previous primer was correctly seated it won't be.

But if the primer pocket is somehow so badly fouled that the primer cup is sitting on a bed of burned primer compound then, yes, clean it. Remember that loading cases on most progressive reloading presses such as the excellent Dillon 550 the case is decapped and a new primer seated into an uncleaned pocket.

 

[enfieldspares]

The concern I would have is not accuracy if a primer is not seated correctly but that...with Boxer primers...if it is seated proud then there is a risk of the bolt (or breech face) as it closes on the round setting the primer off.

This cannot happen with a proud Berdan primer as the anvil is inside and part of the primer pocket. A primer standing proud if Berdan always has its priming compound "clear" of its anvil. A Boxer primer always has its priming compound in contact with its anvil. So a crushing or striking or a proud standing Boxer primer could cause the compound to "fire".

It happens (and it is how they are essentially in fact able to be tested) with a Boxer primer as the anvil is in the primer. Boxer primers are tested by dropping a steel ball bearing of a certain weight onto a loose primer in an "all fire" vs "none fire" drop test. I think below 1" height drop none must fire. About 10" drop height all must fire?

 

[Norfolk Deer Search]

Never cleaned a primer pockets , just one of those jobs I’ve never seen the point in doing.

 

[Tarquin]

I never used to but do so religiously now. All part of my case prep.

 

[suburban bushwacker]

Wet tumble. primmer pocket cleaning comes included

 

[Bowland blades]

cleaning the crud out the primer recess of the case might be fine - until its not ! Its a quick job and the tool is cheap so daft not to , no serious target shooter would leave that stage out and those guys never need to take say a fast follow up shot !
Individuals make their own minds up !

 

[Tikkat1x]

my cases go through the ultrasonic after depriming, so there always spotless in 15 mins, then 2 hours in the dry tumbler after resizing

 

[Smellydog]

Use too but don't now.

 

[Foxyboy43]

As per Smelly - don’t bother now but I always check my reloads for primers sitting proud. That said such instances are very few and far between…

 

[cjm1066]

Moved to wet tumbling, primer pockets cleaned by default.

Always uniformed primer pockets in new brass.

 

[Liveonce]

cleaning the crud out the primer recess of the case might be fine - until its not ! Its a quick job and the tool is cheap so daft not to , no serious target shooter would leave that stage out and those guys never need to take say a fast follow up shot !
Individuals make their own minds up !

Not so sure

 

[ASHCROFT9491]

Wet tumble. primmer pocket cleaning comes included

This is best option for me, cleans the pockets at the same time

 

[Bowland blades]

Not so sure

Remember Top end target shooters talk in their terms of use and then there are sponsorships in this case Lapua supplies his Brass. Also he is mostly laid down on a big clean mat using a single shot rifle without a magazine.
Stakers loose brass and loose plenty . our brass tends to be mixed as to times fired and all sorts of stuff mixes in our pocket lint or gets picked from a muddy puddle . When i did the F class stuff my brass was pretty mint and chambers of my guns where mint . I am sure most of us end up with ammo of mixed firings unsorted ?
Indeed i am sure the man has done a video on his hunting practices and they where way different as was mine when i laid on a big mat and put a leather cloth over my action when it starting raining , while waiting for my term in the line .
The guy is a legend , but do remember he is top of the tree with manufactures / sponsorships etc

 

[Rutland lad]

my cases go through the ultrasonic after depriming, so there always spotless in 15 mins, then 2 hours in the dry tumbler after resizing

I must be doing something wrong - I don’t always find the primer pockets are clean after using ultrasonic.
Perhaps you’re using a different solution mix to mine.

 

[Hillside]

Hi Roonster,
To follow up on what "enfieldspares" posted above; If you leave the carbon in the pocket, I'm guessing it could exacerbate "gas etching" on the bolt face if the primer doesn't make a good seal. I always clean mine (only takes seconds with a cordless). I also like to have the primer a fraction under the head of the case head.
I've often wondered how much the pressure varies with badly seated primers (especially on multi fired brass) and if it alters the ES's shot to shot.

Hopefully Laurie can jump in and answer your questions.

Cheers
Hillside

 

[Bowland blades]

I must be doing something wrong - I don’t always find the primer pockets are clean after using ultrasonic.
Perhaps you’re using a different solution mix to mine.

I still use corn cob and a tiny amount of brasso , then use a primer pocket cleaning tool . Might be old fashioned but its been working for me for more than 20 years on the range and in the field

 

[Tikkat1x]

I must be doing something wrong - I don’t always find the primer pockets are clean after using ultrasonic.
Perhaps you’re using a different solution mix to mine.

a dash of fairy and a tea spoon of citrus acid, the always spotless, in out and primer pockets,