but feel free to ask for more-info...
I bought a MK2-10" last fall (mfg ~84), it is "Used" but not "ABused".
The bore was shiney-clean and the chamber/muzzle were un-marred,
so I figgered the other parts and pieces would be replaceable...
I've changed-out the bolt-parts (firingPin, return-spring, ext-hook etc)
I also **thought** the hammer-hook (ie. sharp edge that engages the sear)
looked like it might have been modified/reduced a teenie-bit...
so I got a factory-hammer assembly from RimFireSports when I ordered
a VQ-sear and HogueGrips and Wigand-ScopeRail and "stuff"...
well, here's the problem... it tends to go FullAuto
BEFORE the above parts were ordered and replaced... and still does it.
I have the advice and co-examination of a couple guys from my Range/Club that
are Ruger-MK enthusiasts... and the conclusion is that I haven't changed
the "Disconnector", so that MUST BE IT

well, it seems that Ruger has the disconnector KA011 marked with an *
meaning that it is factory-fitable-part...
It was deduced that when the bolt is running-back and cocking the
hammer that the hammer is NOT being held-cocked.
... about 40% of the time, it fires "OK"
... about 40% of the time, it fires once and then NOT-cocked,
BUT the new cartridge just chambered will have a faint/wee little
firing pin mark, as from inertial thrust of the firing-pin coming forward.
... otherwise... I'd better only have 1-2-3 cartrides loaded as they
will be gone... as fast as a lawn-mower fires... not a fast pop-pop-pop,
but a FrpFrpFrp!!
It's an interesting experience... but the gun is not designed for it,
so it will cause other problems to continue...
On the PLUS-side... shooting SingleShot... it is a really nice pistol !!
and a contender-in-waiting to join my P512 as my Co-Favorite pistols.
So... ideas, suggestions... ??
1. anyone else experience anything similar to this ?
2. replace the original parts and ship it to Ruger ?
3. get a Disconnector (Brownells, ?) and hope to fix it myself ?
... EDIT: just checked, Disconnector-Part Not-Avail via Brownells ...
4. take a file to my disconnector and really mess things up

Thanks.