Found an interesting post over on The Reloading Bench forum. [URL=arxiv.org/ftp/arxiv/papers/1203/1203.2701.pdf]Primer Test[/URL]

Poster there experienced delayed fire with Tula primers.  I had the same experience with Wolf primers in my Garand (30-06).  I could hear the hammer hit the firing pin and then the round fired.  Load was 47gr WC846.  Ball powders are usually harder to ignite, especially in a light load.  The test had a misfire in 30-06 with H414 powder even though the primer showed a good hit.

The Tula and Wolf primers are made with the new lead-free mixture, diazodinitrophenol (DDNP) rather than the usual lead styphnate/lead azide mixtures.

This is what the tree huggers have forced the US military to go to by the end of FY 2012, (This month)

http://wstiac.alionscience.com/pdf/WQV11N2.pdf

Thanks for the article.  It does recommend further study BEFORE issuance of DDNP primers to soldiers "3. Shelf-life and long term stability comparable with lead based
primers."

THE NEW LEAD-FREE PRIMING COMPOUND diazodinitrophenol (DDNP) BECOMES UNRELIABLE WITHIN A FEW YEARS!!!!!!!!!!!


Yes - I meant to shout that.  I have been warning people about "lead free" / diazodinitrophenol primers for more than 5 years now.  

Cases of CCI lead free practice ammo are routinely marked "USE WITHIN 5 YEARS."   After that amount of time, the DDNP starts to become unreliable.  Apparently, it is extremely suceptible to absorbing water vapor  / is "hydroscopic."   Even the minimal moisture in the powder and air inside the case can affect it over time.  There may only be 1 to 2% failure at 5 years, but it increases from there.  Eventually, MOST of the primers will be "duds."

The article also mentions this ominous fact:  "None of these companies offer lead-free primers
as stand-alone components, and to our knowledge, DDNP-based primers are currently only available in training ammunition, with
no major supplier offering service caliber or hunting ammunition for self-defense, law-enforcement, hunting, or military duty."  

The companies KNOW their DDNP primers do not last over time.  But they still market ammo with them - to us especially!  

This is NOT some .gov conspiracy; it is simply a chemical property of DDNP, and they have worked to make the primers last longer.  BUT - DDNP primers will NOT last as long as Lead Styphnate ones.

OK. So I have some cases and several boxes of Wolf primers. How do I tell what they are?

Unless they say Lead Free you should be fine,I shoot lots of Wolf Tula Primers in all sizes  and never had any issues.

http://bulletin.accurateshooter.com/2011/10/surprising-results-in-dept-of-defense-lead-free-primer-tests/