I recently started working on my stash of milsurp LC 12 brass and it seems really hard to work with compared to other years of LC I've loaded.  Trimming is nasty as this batch comes in at 3.93" and doesn't cut easily.  Full length sizing is another issue as I have broken my bench and bent a press handle while sizing this LC 12 brass.  Finally, priming is no walk in the park either even though I remove the crimp and run a pocket truing tool before priming.  After all that...there is still a boatload of resistance to getting a primer in the pocket.  I have loaded batches of LC 06, 10, 13 without these issues.  Has anyone here had a similar experience during case prep with LC 12?

I have seen a lot of funky primer pockets in LC brass, but not excessive toughness.

Now Igman brass (Yugo IK headstamp) has proven to be some tough stuff.
The good news is most of it has over 30 firings on it and still going strong!  

Out of the 800 of those I bought ten years ago I probably have 790 left.

So hopefully after the extra work you will be rewarded with long life!

I sure hope so PP because this brass is going to make an old man out of me

Your using a carbide blade on your trimmer, right? I lube the crap out of my shells with the rcbs spray lube. The lee lube sucks. My lee press does a good job resizing. Allot of work to brass prep these big ass shells but worth it in the end.

I'm using the lee setup.  My trimmer is a Lyman Accu Trimmer and I'm using whatever cutter came with it.  For lube I'm using Imperial sizing wax and, yes 50 Shooter, I'm lubing the inside of the case mouth.  I have to full length size this batch two to three times before it will chamber in my AR-50.  This LC 12 is just tough brass to work with, but as Pugglepod9000 pointed out, it may load many times.  It's just plain weird that  all my other lots of LC were relatively easy to work with and then comes this LC 12 that stares at me from the bucket on the floor like it's Chucky daring me to start working it again.

I have the same trimmer. Order the carbide cutter. Makes a difference. Sucks they don't just ship with a carbide cutter but all trimmer manufacturer ship with regular cutters.