Berdan primer seating depth - reloaded GP11 cases(7.5x55 Swiss)

JR Hartman

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hey, so I finally got 50 cases of Swiss brass deprimed, cleaned, resized, trimmed, deburred etc.

I then carefully trimmed out the military primer crimp. Very carefully, good small motor control etc.

now, using a hand primer tool, load up 50 Tula Berdan primers. Press the first one in, and it seats all the way in and is a few thou below the level of the case head. too low for my liking.

I do a few more, but am aware, and seat all the rest as they should be.

now, 2 questions.

question the first. Can I load and fire this one?

and secondly, is there a way to avoid this without having to carefully do each one like I did these? some sort of adjustable stop? Shorter primer rod? etc?
 
hey, so I finally got 50 cases of Swiss brass deprimed, cleaned, resized, trimmed, deburred etc.

I then carefully trimmed out the military primer crimp. Very carefully, good small motor control etc.

now, using a hand primer tool, load up 50 Tula Berdan primers. Press the first one in, and it seats all the way in and is a few thou below the level of the case head. too low for my liking.

I do a few more, but am aware, and seat all the rest as they should be.

now, 2 questions.

question the first. Can I load and fire this one?

and secondly, is there a way to avoid this without having to carefully do each one like I did these? some sort of adjustable stop? Shorter primer rod? etc?


JR I am not familiar with the Berdan primers you are using but I am assuming they are the correct primer for the cases you have. Regarding seating the primers. All primers should be seated firmly in the bottom of the primer pocket. Even if this means the primer is a couple thou below the head of the case. The priming mixture in the primer cup is percussion sensitive and must be crushed between the anvil (the little pin in the centre of the berdan case primer pocket . On boxer primers the anvil is built into each primer) and the firing pin to achieve consistant detonation. If the primers are not fully seated in the primer pocket you will likely end up with the occasional mis-fire.
 
Those are the right primers then, I bought ones meant for the x39 which will work but aren't as powerful.

Have you tried firing the primer only with them seating deep? If they fire I wouldn't worry about it.
 
No issue at all with primers being slightly below flush, as long as they fire reliably, ie the pin can reach. You WANT them bottomed out against the pocket and with a slight pre load between the pellet & anvil. Seated not bottomed out, and the firing pin is what will seat them fully when you pull the trigger, leading to inconsistent ignition.

As long as they aren't seated so deep they don't fire, you're GTG. I would go back and reseat the flush primers till they bottom out, then a slight squeeze more to preload.
 
its quite a bit deeper tho, not just a couple of thou. its .019"!! a couple are roughly .006"

my GP11 factory ammo is .001-.002

if it wasn't such a pain to deprime again, and if I hadn't already resized all(50 cases), I'd just try to fire the deep one and one of the level ones.

Will the firing pin even go 0.19" plus the required amount to hit the anvil?
 
its quite a bit deeper tho, not just a couple of thou. its .019"!! a couple are roughly .006"

my GP11 factory ammo is .001-.002

if it wasn't such a pain to deprime again, and if I hadn't already resized all(50 cases), I'd just try to fire the deep one and one of the level ones.

Well, that is quite deep, but I don't imagine any problem. I'm at my bench right now, just measured some reloads in front of me, and they're 7 thou below flush; fire just great, with low SD and ES. 19 thou isn't a ton more in the scheme of things - firing pin protrusions are like 60 thou plus.

Will the firing pin even go 0.19" plus the required amount to hit the anvil?

I'm sure it will, but one very easy way to confirm; prime up an empty case or three and drop the hammer.
 
awesome, thank you all. I have reached the same conclusion, and have done some research on line and the people who have been doing this for a while have also agreed that its just fine.

Now I just need powder. Tomorrow?
 
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