Decapping Problem

[308Jeff]

Bought some really dirty 40 S&W brass. Got the bright idea to briefly wet tumble it with the primers still in so it was clean(ish) before I decapped and resized.

I know now that was a mistake, and the source of my problem.

Took me a while to figure it out, but what's happening is about 1 in every 7-10 pieces of brass gets "hung up" when I'm decapping/resizing. By that I mean the primer isn't fully exiting the case. The interesting thing is, it certainly IS exiting the case, but the anvil is getting stuck on the decapping pin and the primer is being partially reseated as the pin withdraws from the case. A second round through the die clears it.

Corrosion of the primer to the case from the wet tumbling is the source. Lesson learned, and easily preventable in the future.

What I should do is dump this brass in a box, squirrel it away, and try to forget about it. I already have 12,000 or so pieces of fully processed 40 S&W brass. Just not sure if my OCD is gonna let me walk away from it.

Any ideas?

[Pressman]

Idea, Yes, do like the Dillon guys and radius the end of the decapping pin. Break the sharp, square edge to prevent the pin from grabbing the primer and pulling it back into the case.
I can't quite see how wet tumbling would so quickly create enough corrosion to not allow the primer to push out. It would be like decapping crimped military primers. They need a strong push to get them out.

Ken

[JimB..]

Seems unlikely to have been caused by wet tumbling. I have had a similar problem with some filthy 9mm that I bought, but only with 1% or less of the cases and I didn't check head stamps to look for a pattern.

If it bothers you just dump it all in the scrap bucket or PIF to a new reloaded that will be happy for the brass.

[country gent]

308 Jeff I have found that on hard to decapp ammo ( crimped primers or hard pressed and or corroded) thaty putting a light radious on the decapping pin with a fine stone helps keep the primers from gripping the pins sharp corners and allows it to fall off easier. I do this with a sharp fine stone and the stem mounted in a drill press at fairly high rpms. cut a light radious on the face to edges removing sharp corners.

[bosterr]

This same exact thing happens when I load .41 mag on a Dillon SDB. When using Federal LPM primers about 20 of 100 do this. When I use CCI LPM, it happens about 3 times in 100. I both rounded and then thinned the punch pin. The same machine when loading 45 ACP never does this, nor does my other SDB set up for .44 mag.

[Shawlerbrook]

Universal decapping die without resizing might make it a little easier.

[oteroman]

Not sure 100% but I would bet it is a drying issue. When I wet tumble but only if I have a good 2 hours of sun (Denver) to dry on a towel on my driveway. I would never wet tumble at night with plans to lay out the brass in the morning (sticky primer issues). Is no sun I put them in a small toaster oven on low 200 degrees.


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[oteroman]

I will try the radius on the recapped too.


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[308Jeff]

The radius on the pin is a great idea. Thanks, guys!

The reasons I believe it's related to wet tumbling are:

- Never had this problem with the ~12,000 pieces of 40 S&W I didn't tumble.
- It makes sense that it happens now if the primers are requiring more pressure to remove, causing the anvils to wrap around and grip the decapping stem.

I'll radius that pin and get back to y'all. Thanks again!

[pertnear]

I had the same problem but it was from a police outdoor range where moisture had migrated into the primer pocket to cause the corrosion. My solution was to soak all the brass in PB Blaster, a fine oil used to loosen frozen/rusted bolts. I'm sure anything similar like Liquid Wrench would do the same thing. Not a lot is needed because the oil oozes into the flash-hole & seems to even wick its way up the outside primer. Overnight is long enough to leave them. I clean them up some before sizing but the residual oil help & eases the sizing process. I was getting 10% hang-ups before & after the PB treatment it was zero.

Try it.

[308Jeff]

Great advice. Thank you, pert!

[edp2k]

The Dillon decapping die has a spring loaded decapping pin.

if the primer is stubborn and it takes more effort to push out,
the decapping pin spring gets compressed and when the force gets high enough
or the spring bottoms out, the now free spent primer allows the spring on the pin to
"fire" the pin forward and the spent primer gets flung off.

Mike Dillon was a heck of a Mechanical Engineer and the Dillon dies are engineered very well.

[308Jeff]

Interesting. Dillion is local for me. Might run up there and pick one up if radiusing this one doesn't help.

[RMII]

The rounded over pin is the ticket. I stumbled on to this once when I was getting stuck like you, but when I tried a few on another press that had a well used (worn) pin I had no problem. Went back to the 1st machine, knocked off the edge and all better.

[308Jeff]

Thank you, sir.