Primer Pocket Size?

[Thumb]

I've been going through my Lake City once fired brass and when putting them through the Dillon swagger I've noticed that some of them are too big or maybe do not need it. Just to test them out I ran a few of them in my press installing the primers. Now most of them felt normal but a few of them it seemed that the primer went in too easy, with one of the primers even falling out which is not good. I've run Lake City brass before through this stage and never had a primer problem until now. I know my swagger is set properly and even so I backed it out just a tad just in case.

Is there a go/no-go gauge for primer pockets or at least a dimension to go by?

 

[Martin52]

I recorded these dimensions some time ago for LR primers -

Primer pockets max. 0.2100 min 0.2085 width.
Max 0.132 min 0.125 depth.

Also, try a pin gauge.

Martin

 

[bigedp51]

Below a pin gauge on a .223/5.56 case at .1745 has entered fully into the primer pocket. This case is going in the scrap brass bucket.

Buy at least two pin gauges that are slightly smaller than the diameter of the primers you are using. But the single .1745 pin gauge is the one I use the most after removing the crimp.

The crimp is just at the case mouth so no matter what the instructions tell you once the end of the swage is past the crimp STOP.
(less is more) And the Germans call this "goodintight". :

After seating the primers any questionable primer can be checked with a Lee depriming tool. If I can push or move the primer with just finger pressure the case goes in the scrap bucket.

I use these standards on the ammo I load for my AR15 rifles because a over gassed AR still has pressure in the barrel as the bolt is moving to the rear. And besides having a loose primer scoring the bolt face the over gassed AR can pop a primer out and jam the trigger group.

Now can your wife spin straw into gold?

 

[Thumb]

Thanks for all that info, it will come in real handy and maybe save me from a bad accident.

 

[bloc]

A company named Ballistic Tools makes go/no-go gages for primer pockets (among other things). Haven't used one yet, but I'm going to give their small rifle primer pocket gage a try. http://ballistictools.com/store/reloading-products

 

[amlevin]

A company named Ballistic Tools makes go/no-go gages for primer pockets (among other things). Haven't used one yet, but I'm going to give their small rifle primer pocket gage a try. http://ballistictools.com/store/reloading-products

Brace up. "Big Ed" is about to let loose with one of his tirades on how this tool isn't "Wuff a damn".

Expect pictures too 8)

Course he doesn't realize that some of us don't feel like investing in an expensive set of pin gauges when we can have a very useful tool for about 1/10th the price of a cheap set of pin gauges.

I use my thumb as a "seating gauge" and funny thing, I can still shoot "bugholes" with my loaded ammo without the primers falling out. Go figure.

 

[asauer]

To be honest, for my ARs I just use a burring tool to lightly chamfer the crimp area in lake city brass. I think it's the best way to do it, as I chamfer just enough to make the primers go in very firmly still. You'll have to try it and get a feel for it- I think it helps make the pockets last longer. No sense in displacing more material than absolutely necessary to get a primer in there.

 

[Thumb]

I need to get a hand primer so I can get the feel of it. Using that LNL press with the big arm leverage is not giving me the feel for it. Does that make sense?

 

[asauer]

Yes. I only load single stage, but I use a hand primer and like that I can feel.

 

[bigedp51]

A company named Ballistic Tools makes go/no-go gages for primer pockets (among other things). Haven't used one yet, but I'm going to give their small rifle primer pocket gage a try. http://ballistictools.com/store/reloading-products

Brace up. "Big Ed" is about to let loose with one of his tirades on how this tool isn't "Wuff a damn".

Expect pictures too 8)

Course he doesn't realize that some of us don't feel like investing in an expensive set of pin gauges when we can have a very useful tool for about 1/10th the price of a cheap set of pin gauges.

I use my thumb as a "seating gauge" and funny thing, I can still shoot "bugholes" with my loaded ammo without the primers falling out. Go figure.

amlevin

I bought the Ballistic Tools gauge for checking all my .223/5.56 primer pockets, the problem with this gauge is the GO end of the gauge is the max allowable diameter of a new primer pocket. And even if this end didn't fit in the primer pocket I still had loose primers.

I did not buy a "expensive" pin gauge set, I bought three individual pin gauges for less than the Ballistic Tools gauge. The pin gauge I use the most is .0005 smaller than the GO end of the Ballistic Tools GO gauge.

Bottom line, with the Balistic Tools gauge at 0.175 I was pushing primers out of the primer pockets with my Lee depriming tool. And with my smaller 0.1745 pin gauge I could not get the primers to move.

amlevin, I'm also loading for my sons AR15 and "DAD" isn't going to be blamed for his bolt face looking like the one above.

And the bucket below contains "once fired" factory loaded .223/5.56 cases that have oversized primer pockets and were NEVER reloaded. And below amlevin is the reason for my madness, 95% of these cases only lasted one firing and had over sized primer pockets.

Bottom line, a over gassed AR15 still has pressure in the barrel when the bolt unlocks and starts moving to the rear. And this gas pressure can pop a primer out and jam up the trigger group. And so far with my primer pocket OCD I have had NO loose primer related problems. And I will admit with a bolt action "MY" standard may be a little high, but better safe than sorry.

As a side note in the early 1970s I bought a bad batch of Remington 9 1/2 primers that had a recall. I went to the range with my 760 Gamemaster 30-06 pump and fired 20 rounds and my bolt face looked like the photo above. This taught me a very good lessen, I now look at every fired primer I shoot. The problem is some firearms throw perfectly good brass away every time you pull the trigger and you can't read primers when they are laying on the ground.

The Germans call my standards "goodintight" and its good enough for me.

 

[bigedp51]

I need to get a hand primer so I can get the feel of it. Using that LNL press with the big arm leverage is not giving me the feel for it. Does that make sense?

Yes

Below a oldy but goodie. With lots of "feel".

The only problem I have when reloading is fighting over who gets to sit down at the bench.

My little buddy even wants to post in forums with me, but if I wake her up my mouse arm gets swatted for moving too much.

Above her left paw is cocked and locked because I moved to take the photo and disturbed her tranquility.

Eat Your heart out CatShooter.

 

[amlevin]

my sons AR15 and "DAD" isn't going to be blamed for his bolt face looking like the one above.

Gosh, I use the Ballistic Tools gauge to cull my .223/5.56mm brass and load for three AR's. None of them have a bolt face that looks like that. Course I do toss the brass that the No-Go end just starts to enter so perhaps I'm using the tool as it was intended.

If you like picking fly poop out of the ground pepper, enjoy it to your heart's content.

 

[expiper]

Big Ed,,,I like havin a cat around,,,they keep mice and vermin away and that keeps the snakes away !!!...my last one was Black and I called him Luky',,,,the coyotes got him,,grrrrr,,,,,thanks for your efforts with reloading questions,,,hav a great day,,,Roger

 

[bigedp51]

Gosh, I use the Ballistic Tools gauge to cull my .223/5.56mm brass and load for three AR's. None of them have a bolt face that looks like that. Course I do toss the brass that the No-Go end just starts to enter so perhaps I'm using the tool as it was intended.

If you like picking fly poop out of the ground pepper, enjoy it to your heart's content.

amlevin

You and I prefer different methods and many people always do differ, and this means you and I do "NOT" have to be at war over a simple gauge. I simply use pin gauges closer in diameter to the primers I'm using, nothing more. So lets kiss and make up and stop arguing.

 

[Brians356]

Below a pin gauge on a .223/5.56 case at .1745 has entered fully into the primer pocket. This case is going in the scrap brass bucket.

What class of pin gage is that (I'm guessing "X") and do you use a "minus" or "plus" variant? (I'm guessing "minus".)

PS I see the "four digit" gages are available in Class Zz, so the "minus" nominal 0.1745" would measure 0.1743". Useful!

 

[bigedp51]

What class of pin gage is that (I'm guessing "X") and do you use a "minus" or "plus" variant? (I'm guessing "minus".)

I purchased three pin gauges, 0.1745, 0.1740, and 0.1735, the Ballistic Tools gauge I bought is 0.175 and over the max allowable diameter of the primer pocket?????

Vermont Gage Steel No-Go Plug Gage, Tolerance Class ZZ, 0.1745" Gage Diameter
http://www.amazon.com/gp/product/B0006JDBII/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

As you can see below on the milspec 5.56 dimensions the plus-minus primer diameter is 0.1738 to 0.1745 and the 0.1745 pin gauge is the one I use the most after removing the crimp on Lake City and commercial contract 5.56 ammunition for the military. It also shows why the Ballistic Tools gauge at 0.1750 is too large.

 

[Brians356]

These gages are sold either "minus" or "plus" 0.0002" in Class Zz ("go" and "no-go"gages respectively.) Which do you have? (The link you pasted shows a "no-go" gage, and the actual diameter would be 0.1747".

The "no-go" will be more conservative (i.e. a case will be discarded a bit sooner than a "go" gauge would indicate.) Maybe that's the sensible choice.

 

[Thumb]

Maybe I'll just take some brass stock and make my own gauges on the lathe, that would be the cheapest for me.

 

[bigedp51]

These gages are sold either "minus" or "plus" 0.0002" in Class Zz ("go" and "no-go"gages respectively.) Which do you have? (The link you pasted shows a "no-go" gage, and the actual diameter would be 0.1747".

The "no-go" will be more conservative (i.e. a case will be discarded a bit sooner than a "go" gauge would indicate.) Maybe that's the sensible choice.

My pin gauge is marked 0.1745 and measures the same with my micrometer and vernier calipers. All three of the pin gauges measure what they are marked.

Third Correction: My 0.1745 pin gauge is followed by a minus sign which means the pins are .0002 smaller than marked. My analog micrometer might read a fly hair below 0.1745 and my $35.00 digital vernier calipers are only accurate to 0.0005 and reads 0.1740. If this is correct then the pin is actually 0.1743 and I have three gauges giving readings between 0.1745 and 0.1740 . Which is approximately plus and minus a RCH ;D

 

[searcher]

I also recently ran into big differences in LC primer pocket swaging results while processing 5,000 cases a few weeks ago. Prior to this batch, I had beeen running 2008 and 2009 LC brass. This new batch was a few 2009, mostly 2011, 2012. The difference in results was a result of the change in the manner of how the pockets were crimped. 2009 and prior, they have the "circle" around the primer, whereas the 2010 and newer have four small "stab" marks somewhat resembling a rimfire firing pin having stabbed the metal in four equally spaced places around the perimeter of the primer. They require a heavier setting on most pocket reaming devices. I went over them again with a slight chamfer to further knock off the four protrusions caused during staking the primer.