Primers seating deep and strange mark around primer pocket

Leon123

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Good day everyone I am having a problem with primer seating. I am still new to reloading I noticed that my PMP brass the primers seated very deep. There is also a strang triangular mark around primer pocket on those shells. It was my first time priming cases did I use to much pressure?
 

fourfive8

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Once in a while brass shows up that is out of spec. But it is extremely rare. Possibly something else is going on? Pictures would help. Good lighting and macro as you can get with a phone cam is usually enough. Sometimes military brass with crimped primers does odd things when de-primed or re-primed... but can't tell without good photo. The only other thing I can think which would be triangular in nature is the anvil inside the primer. Most anvils are triangular and might leave a "triangle" mark if too much pressure was applied to seat primer.... but whew, yes that would suggest way too much pressure. :)
When seating you should "feel" just a little resistance as the primer bottoms out in the pocket then ideally just a tiny bit more compression of the anvil on the seat bottom for best seating.

And actually a primer seated from just at level up to 5-6 thousandths inch below the base is normal and preferable to anything seated above the level of the base- which is not good.
 
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Leon123

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Hope these are fine
20200827_135709.jpg
20200827_135701.jpg
 

fourfive8

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Actually they “look” fine. You can feel across the base with your finger. If the primer is level with or slightly below the case’s base- should be good to go. Just a wee bit of anvil compression on the bottom of the primer pocket is ideal. That helps assure all the force of the firing pin strike is used to ignite the primer and not being used (absorbed energy) to finish seating the primer.

Many calipers have a depth gauge feature opposite the jaws and can be used to get a depth measurement— should be level up to about .005-006” below. If you compare various factory loaded ammo, you’ll notice that same slight variation in seating depth depending on lot and brand. But they will always be level or up to about .005-.006” below base level.
 
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Leon123

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Actually they “look” fine. You can feel across the base with your finger. If the primer is level with or slightly below the case’s base- should be good to go. Just a wee bit of anvil compression on the bottom of the primer pocket is ideal. That helps assure all the force of the firing pin strike is used to ignite the primer and not being used (absorbed energy) to finish seating the primer.

Many calipers have a depth gauge feature opposite the jaws and can be used to get a depth measurement— should be level up to about .005-006” below. If you compare various factory loaded ammo, you’ll notice that same slight variation in seating depth depending on lot and brand. But they will always be level or up to about .005-.006” below base level.
Thanx alot the Sellior and Beloit did seat flush and a few just slightly below. I pressed it till I felt it stopped and just a bit of pressure. I was loading at a shop that you can rent the reloading station and they had a bench primer the guy showed me quickly wat to do. Still need to trim some cases I think and load the charge and bullet
 

PHOENIX PHIL

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The last picture showing two rounds between your thumb and forefinger, the round on the left concerns me. The one on the right appears to be fine. But that one one the left, the pocket does not appear to be round, looks quite oblong in fact. It may be the picture, but at the 11 o'clock position it even looks like there's a gap. And from roughly the 3-5 o'clock position, it looks like the edge of the primer has been crushed inward. I'd be leery about loading and firing that one.
 

Leon123

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The last picture showing two rounds between your thumb and forefinger, the round on the left concerns me. The one on the right appears to be fine. But that one one the left, the pocket does not appear to be round, looks quite oblong in fact. It may be the picture, but at the 11 o'clock position it even looks like there's a gap. And from roughly the 3-5 o'clock position, it looks like the edge of the primer has been crushed inward. I'd be leery about loading and firing that one.
I think I am going to toss that one then. There looks something not right with that one. I bought these brass once fired so I guess maby there is something wrong with that one
 

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You never know what you are going to get with once fired. Wonder if those had military crimped primers and went though a de-crimping, swage re-forming press of some sort? That triangular shape on the base looks like a pressure swage of some sort and would have nothing to do with seating a primer. I imagine it would shoot ok but odd looking. Even if they were originally shot out of a rattle-battle semi or full auto rifle of some fashion, doubtful that would cause that odd shape on the base?
 

Leon123

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You never know what you are going to get with once fired. Wonder if those had military crimped primers and went though a de-crimping, swage re-forming press of some sort? That triangular shape on the base looks like a pressure swage of some sort and would have nothing to do with seating a primer. I imagine it would shoot ok but odd looking. Even if they were originally shot out of a rattle-battle semi or full auto rifle of some fashion, doubtful that would cause that odd shape on the base?
This is for a 303 looks like commercial ammo. I did see on some PMP ammo there were the odd shapes are that there is some marks that look like someone took a punch and nocked the case to the primer side if that makes sense
 

bruce moulds

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the primers do look very deep in the pockets.,
that combined with the strange shaped pocket discussed suggest a quality control issue in manufacture or some occurrence afterward.
given safety issues, and the potential to burn the bolt/block face with gas, getting better brass might be an option.
measuring the depth of the primer below the case, and if it id more than 458 suggested would make one consider other brass even more seriously.
you cannot un flame erode a boltface.
bruce.
 

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What primers are you using?
Did you clean the primer pocket? What with?
Did you use a tumbler to clean your brass?
What type: liquid solution, corn cob,
walnut, or metal media?
 

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I agree with Phil on his callout with that one your holding on the left...very odd looking!
The others primers do look very deep...unless thats just the angle of the photo.
 

mdwest

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are you 100% certain you used rifle primers and not pistol primers?

large rifle and large pistol primers are very close in diameter.. both can fit in a large rifle primer pocket and appear to be snug.. but pistol primers are slightly shorter...

1598583080206.png
 

bruce moulds

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good point mdwest.
i use large pistol in some black powder cartridge applications, in large rifle promer pockets.
for black powder pressures and ignition this is quite safe, but could be risky at smokeless pressures,with harder to ignite powder.
bruce.
 

Leon123

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What primers are you using?
Did you clean the primer pocket? What with?
Did you use a tumbler to clean your brass?
What type: liquid solution, corn cob,
walnut, or metal media?
I am using Federal large rifle primers. We did not clean the pockets. I do not own a tumbler so I cleand the inside with a patch on a cleaning rod . The outsides I cleaned with a fine steel wool
 

Leon123

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the primers do look very deep in the pockets.,
that combined with the strange shaped pocket discussed suggest a quality control issue in manufacture or some occurrence afterward.
given safety issues, and the potential to burn the bolt/block face with gas, getting better brass might be an option.
measuring the depth of the primer below the case, and if it id more than 458 suggested would make one consider other brass even more seriously.
you cannot un flame erode a boltface.
bruce.
This could be a quality control issue the guys are talking that one needs brass from same lot or the case volume differ
 

Ridge Runner

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Did you use a plastic, brass or steel cleaning rod or patch eye? This may have expanded and/or deepened the primer pocket, created the ding, and caused the primers to seat further into the primer pocket.

I recommend you get a primer pocket cleaning tool or use a long nylon bristle brush to clean the primer pocket rather than a cleaning rod and patch.

This once fired brass is it military issue or commercial ammo?

Military ammo generally, but not always, has a primer ring/bushing. You'll need a large primer pocket reamer to remove it or purchase large rifle military primers. I have and you can, use a razor knife in place of a reamer, but IMO&E use a primer pocket reamer.

I suggest you only charge and seat a bullet on 10 randomly chosen brass. Go to the range and see how well they work.or don't. If they work no harm no fowl reload the rest of your prepped brass. If there is a problem, you caught it early and can rectify it.

I also suggest instead of fine steel wool, use fine emory paper or even better use brass polish and a rag to clean your brass.

Just my 2 cents.
 

Leon123

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Did you use a plastic, brass or steel cleaning rod or patch eye? This may have expanded and/or deepened the primer pocket, created the ding, and caused the primers to seat further into the primer pocket.

I recommend you get a primer pocket cleaning tool or use a long nylon bristle brush to clean the primer pocket rather than a cleaning rod and patch.

This once fired brass is it military issue or commercial ammo?

Military ammo generally, but not always, has a primer ring/bushing. You'll need a large primer pocket reamer to remove it or purchase large rifle military primers. I have and you can, use a razor knife in place of a reamer, but IMO&E use a primer pocket reamer.

I suggest you only charge and seat a bullet on 10 randomly chosen brass. Go to the range and see how well they work.or don't. If they work no harm no fowl reload the rest of your prepped brass. If there is a problem, you caught it early and can rectify it.

Just my 2 cents.
Thank you no I did not clean inside the pocket just the inside of the case before I deprimed and resized. I only cleaned the brass on the outside after seating the primer. Think I will just shoot of the primers and toss the brass I have only 40 of them and 60 Sellior and beloit brass
 

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