Large rifle primers protrude 0.014" to 0.018" from case bottom...safe to shoot?

[mojomandan]

Hi guys,

I just got done loading 100 Winchester large rifle primer boxer brass cases in 7.62x39. Five of the 100 had very tight primer pockets. I even tried running them through my primer pocket swager to open them up a little, and they did, but the primers on these five cases stick out 0.014 - 0.018" from the case bottom, as opposed to being flush.

If these rounds chamber, would they be safe to shoot?

Thank you!

[vzerone]

Hi guys,

I just got done loading 100 Winchester large rifle primer boxer brass cases in 7.62x39. Five of the 100 had very tight primer pockets. I even tried running them through my primer pocket swager to open them up a little, and they did, but the primers on these five cases stick out 0.014 - 0.018" from the case bottom, as opposed to being flush.

If these rounds chamber, would they be safe to shoot?

Thank you!

They might slam fire from a semi-auto like a SKS, especially since that rifle has a heavy free floating firing pin. They should be slightly below flush so I'd work on achieving that or tossing them.

[curator]

I'd be worried shooting them in a semi-auto as well. Sinclair makes a primer pocket uniforming tool that reams the bottom of the primer pocket to a uniform depth. Easy and fast to use in a cordless drill.

[mojomandan]

Ok, if I cannot seat the primers more appropriately, I will toss the cases.

Thanks!

[turtlezx]

were these 1x fired cases or new ??
did you pull the primers and see if there too tall?
or pockets shallow

[mojomandan]

These cases were purchased as "once fired", but I cannot verify that. They were already deprimed, so I cannot see whether those primers were different than my own.

[LAGS]

I have a Lyman Primer Pocket Uniformer that I ream to depth Every primer pocket BY Hand and not Spun in a drill.
The same tool I use when I convert Berdan Cases to Boxer Cases.
The cases are not Junk.
Just take more time in your preperation.
A swedger will not increase the depth.
Tear down those cases, Ream the pockets for depth, and you are good to go.
The lyman reamer can be used on Perfect cases and not over deepen the pockets.
I say Ream them by Hand, because spinning the cutter in a drill can Waller out the pocket sideways, thus shortening case life.
Take some time, and prepare your cases properly, and they will last almost forever with cast Boolits.

[mojomandan]

Thank you Lags. I will get that tool and give it a go.

[LAGS]

If you had been converting Berdan cases without it, and depending on only the Swedger setting your depth, then you did not do them correctly.
Especially if you used a drill bit to size or cut the depth of the primer pocket.

[brassrat]

My hand primer wouldn't seat large pistol primers well at all. I tried a bunch of things to try and fix including asking for a new rod but nothing worked until I made a rod, now it works. Very puzzling

[Frank46]

Takes more time but I've found that reaming the primer pockets usually works out better than just swaging. Especially when using military cases. Crimp gone and when reaming you get a uniform primer pocket.

[Ballistics in Scotland]

The first point is that this is a dangerous condition in a semi-automatic, not a little but very, and in fact I wouldn't consider it safe in anything. It isn't just a matter of the firing-pin, since slamming the bolt home will impact the anvil against the bottom of the pocket, and the composition onto the anvil. It follows the usual rule of accidents, which is that 0.018 of penetration due to a short firing-pin won't work when you want ignition, but this condition will when you don't want it.

This a puzzling situation. It seems likely that these cases have been intended for large pistol primers. This table, allegedly showing SAAMI specifications, gives the bottom or the height tolerance for large pistol primers as 0.177in. and the top of the tolerance for large rifle primers as 0.133. Put them together and you get primers seated 0.016in. proud of the case-head.

http://s1248.photobucket.com/user/gs...sions.png.html

But this begs two questions. I can see some logic in using pistol primers in such a small case (although it isn't a low-pressure one), but I would still be surprised if Winchester did it. I would be even more surprised to find them making only five out of a hundred that way. Were they differently headstamped in any way? It is possible that the cases were originally Berdan primed (anything being possible on a contract for someone), and the person you got them from has converted them inconsistently for Boxer primers.

The Sinclair tool would surely correct the matter, as thinning the solid web ahead of the primer that much should be acceptable. Alternatively the kind of pocket sizer which swages the hole without cutting should work, especially if you support the case on 5/16in. steel tubing from the inside. But it isn't worth buying much for only five easily available cases. Make sure they are strictly segregated from the cases you will use.

[swheeler]

If it was me I would deprime one that seated flush(should be below flush) and deprime one that was proud, measure the depth of the primer pockets, then you will know. If they need reamed, ream them all to a uniform depth.

[mojomandan]

I ordered a primer pocket reamer as I now see it is an essential reloading tool.

[LAGS]

It is not needed in most cases, but I prefer to check them anyway.
But in 7.62x54 I have found that the Prvi cases sometimes have shallow primer pockets.
Check every case by just a few turns by Hand, and it too can spot primer pockets that are a little tight also.
It wont Cut the width, but you can separate them out much easier, then Swedge those if you want.

[leadman]

I have the RCBS Trimmate and have a primer pocket tool installed on it. I also have an inside case deburring tool that works to remove the military crimp and bevels the edge of the primer pocket. This makes primer seat with less effort to just below flush.
After you use the Lyman primer pocket reamer you may still need to bevel the edge of the hole some. A pocket knife will do this in a pinch.

[Good Cheer]

Thumbs up on the Lyman pocket reamers, big'un and the little'un.