how loose is too loose on primer pockets

[mattkarstetter]

I have a ga precision 260 built on a badger m 2008.

Loading with H 4350 at 42.5 grains.

brass is bumped back .003 on each firing.

using lapua and nosler brass, with cci br2 primers.

on the third and fourth firings of the brass. I am using the rcbs hand primer, older style that utilizes the shell holder.

my question regarding the ease at which the primers are going in. some are easir than others, but they are all starting to go in with relative ease.

what can go wrong with a loose primer pocket?

I am only moving the brass .003 from the fired cases. Is there any catastrophic risks involved.

I am new to these "premium" brands of brass. I never got my older brass to go this long in my other rifles. Either I would loose it or it cracked or looked bad enough to move on.

I have been cutting the pockets with the sinclair cutter described in the brass prep sticky by tresmon.

It seems that the primer can only get to the bolt face before it stops even if the pocket is loose, thus preventing a problem. I just wanted to check before i screw up big time.

thanks for your input in advance.

 

[Teggy1]

Re: how loose is too loose on primer pockets

Pressure is what is loosening your primer pockets, not sizing.

That being said, and I may be wrong, I thing the biggest issue with loose primer pockets would be the possibility one may fall out, and leave powder where you don't want it.

my $.02

 

[turbo54]

Re: how loose is too loose on primer pockets

Loose fit can also foster gas leakage around the primer which can/will start to cut a ring into your bolt face. Highly unlikely that it would allow enough leakage to blow enough hot gas into your face - plus your action has a vent to stop that.

Perhaps the greatest danger of loose pockets is that it is an indicator of casehead growth - which lends itself to casehead separation, which is ugly.

That all said... maybe I'm doing it wrong and taking chances I ought not to - but provided the primer STAYS in the pocket, I go with it, and havent had a CHS or even a soot ring around my primer yet. I think it will eventually happen though. Seems that if you play this game long enough it's gonna happen to anyone/everyone.

 

[The Mechanic]

Re: how loose is too loose on primer pockets

To loose of a primer can cause flame cutting of your bolt. Easy to spot. If you look and see black sooty shit around any part of the primer. Also look for that black sooty ring around your firing pin. Bad JuJu.

If you REALLY need to make your brass last as long as possible you can swage the primer pocket. This normally moves brass away from the top of the pocket but it actually presses a little in the middle of the pocket and will give a "little" bit tighter pocket.

Over sizing brass by pushing the shoulder back to far can also make a primer "unseat" until the brass also moves back to impact the bolt face. (depending of the extractor style)

 

[The Mechanic]

Re: how loose is too loose on primer pockets

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Loose fit can also foster gas leakage around the primer which can/will start to cut a ring into your bolt face. Highly unlikely that it would allow enough leakage to blow enough hot gas into your face - plus your action has a vent to stop that.

Perhaps the greatest danger of loose pockets is that it is an indicator of casehead growth - which lends itself to casehead separation, which is ugly.

That all said... maybe I'm doing it wrong and taking chances I ought not to - but provided the primer STAYS in the pocket, I go with it, and havent had a CHS or even a soot ring around my primer yet. I think it will eventually happen though. Seems that if you play this game long enough it's gonna happen to anyone/everyone.</div></div>
We must have been typing at the same time.

 

[MitchAlsup]

Re: how loose is too loose on primer pockets

Summary: If you see soot on the sides of the primer pocket between the primer and the pocket, the pocket is too loose. If you don't cull that case bad things can and will happen.

I have a set (100) of brass with 30+ reload cycles on them, shooting a stiff 47.8 gr Varget and 155 Scenars at 2950 fps that have not lost a single primer pocket.

 

[Unsichtbar]

Re: how loose is too loose on primer pockets

Of course allways inspecting for any sign of case head separation before proceeding. I use wolf russion primers which are larger diameter. I also use a RCBS primer pocket swage to reform the primer pocket when needed. I also have cases reloaded 20++ times, I anneal every fifth reload to maintain neck tension.

 

[jlow]

Re: how loose is too loose on primer pockets

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body"> I also use a RCBS primer pocket swage to reform the primer pocket when needed. </div></div>
Can you please explain this a bit more in detail? Specifically how the tool will reform the primer pocket if it becomes stretched out.

 

[mattkarstetter]

Re: how loose is too loose on primer pockets

i have the dillon super swage for my 556 cases. will using this swage move the metal.

 

[mattkarstetter]

Re: how loose is too loose on primer pockets

this all started when i saw a dimple on the primer. i believe it is being caused by the firing pin hole being a little bigger on the bolt but am not sure.

this was while using 43 grains of h 4350. at that point i started looking at the brass and felt the primers get a little loose. this was only on new lapua brass. the nosler brass handled the 43 grain load with no problems whatsoever. no loose pockets etc.

from memory this load was around 2 grains below the hogden manual max.

this rifle is on a badger action. my buddy shoots a 260 on a templar action. i gave him some of my ammo at the last match and his rifle did not have the dimples on the primer.

i understand that every rifle is different, but i concluded that it must be a little bit bigger firing pin hole.

this is a guess though.

 

[Unsichtbar]

Re: how loose is too loose on primer pockets

"the case is raised into the die body where the support rod makes contact with the web area and as the press stroke is completed, the spud is driven into the primer pocket and reams the crimp out. The ram is then lowered and as it hits bottom, the case stripper, which stops it's downward travel a bit before the ram, bumps the case off the spud."

Ajust support rod a little presure at a time, to much force can bend the rod. there is a learning curve. You want just a light pull when the case is bumped off. I have not used a Dillon for this only RCBS. Hart makes at tool for reforming the primer pocket ( which I have) it does not work as well as RCBS.

Several of the people I shoot with use the RCBS on there 7mm RSUMs

 

[leadbullet]

Re: how loose is too loose on primer pockets

if the fired brass goes back in the same rifle, you don't have the push the shoulder back at all, simply resize enough of the neck until the bolt close easily. What you are doing is destroying the fireforming of the case, and refireforming everyshot messing with the headspace. lose primer pocket could result from that.
hope this helps bud.

 

[427Cobra]

Re: how loose is too loose on primer pockets

Your FL sizing your brass too much, that is unless this is for a semi auto, on bolt rifles .001-.0015 bump, back off your charge, 2800 is plenty fast enough with 140's, as far as the primer pockets go, I don't let mine get too loose, slight resistence is the limit for me, I mark those cases with a red sharpie an leave them where they eject, I have some Win 7-08 necked down to 260 that have been fired 15 times

 

[Fuzzball]

Re: how loose is too loose on primer pockets

I suppose as long as primers don't fall out you can keep using the cases.

Bigger issue is why are the pockets getting loose in the first place? Usual answer is you're loading hotter than those cases can withstand and that really isn't good practice. But it has nothing directly to do with a potential for a head seperation, that's caused by setting shoulders too far back.

 

[jlow]

Re: how loose is too loose on primer pockets

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Unsichtbar</div><div class="ubbcode-body">"the case is raised into the die body where the support rod makes contact with the web area and as the press stroke is completed, the spud is driven into the primer pocket and reams the crimp out. The ram is then lowered and as it hits bottom, the case stripper, which stops it's downward travel a bit before the ram, bumps the case off the spud."

Ajust support rod a little presure at a time, to much force can bend the rod. there is a learning curve. You want just a light pull when the case is bumped off. I have not used a Dillon for this only RCBS. Hart makes at tool for reforming the primer pocket ( which I have) it does not work as well as RCBS.

Several of the people I shoot with use the RCBS on there 7mm RSUMs </div></div>
Thanks! Appreciate you taking the time out to give us the details. Will get one and give it a go.

 

[former naval person]

Re: how loose is too loose on primer pockets

jlow...read Fuzzball's post. You are ruining your brass with too hot loads. You cannot, no matter how hard you try, get a quart out of a pint pot. The swage dies are meant to remove a crimp from military brass. Nothing more. They will NOT revive a dead case...which you have created by over-pressure loads. Don't spend money on those dies for the purpose you intend. Just back off your loads to a proper node and enjoy better case life...plus the chance of being able to see the groups as they form. When the gases don't blind you. JMHO

 

[jlow]

Re: how loose is too loose on primer pockets

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">jlow...read Fuzzball's post. You are ruining your brass with too hot loads. You cannot, no matter how hard you try, get a quart out of a pint pot. The swage dies are meant to remove a crimp from military brass. Nothing more. They will NOT revive a dead case...which you have created by over-pressure loads. Don't spend money on those dies for the purpose you intend. Just back off your loads to a proper node and enjoy better case life...plus the chance of being able to see the groups as they form. When the gases don't blind you. JMHO </div></div>
Thanks for writing in about your concern. I am actually not using hot load, but all primer pockets eventually get looser even from normal firing, at least mine does. I think the case heads being so much thicker usually resist stretching, that is why you don’t have to resize them. However, stretch they do and it is a slow but one way process, so just looking for ways to extend the lives of those puppies that I neck turned – LOL! Even if it does not work, it will not be wasted as I do have crimped brass that need Swaging.