TargetTalk

I have seen comments about this pistol being fragile and having parts breakage problems (last time the sales thread of three Toz35´s by "J" , viewtopic.php?t=37682 )

So, exactly how fragile is the pistol?
What parts usually brake?

My pistol came with spare firing pin and hammer so I guess those may need to be replaced sooner or later.

I have also read numerous times that spare parts for mc55-1 are even more rare than those for Toz35.

Of course, having unused parts gives some options. My friend works at a dental manufacturing company. They machine parts out of titanium and do precision castings of Cobalt-chrome alloy. That Co-Cr might be suitable material to replicate the firing pin and hammer. Anyone has experience with that material?

Your questions raise some good points.
The owner's manual for the MC-55 (MU-55-!M) has a maintenance schedule that specifies life expectancy of the most likely parts to need attention:
Trigger spring: 125,000 cycles
Rod assembly: 125,000 cycles
Striker: 8,500 cycles
Hammer: 125,000 cycles

Those seem like pretty stringent specs. In fact, the entire manual reads like a technical manual for a scientific instrument rather than the usual documentation that one typically sees.

http://toz35.blogspot.com/2010/09/mts55 ... eries.html

Best Regards,
Jim

The MC-55 manual is citing an estimated "mean time between failure" for the parts, which is not terribly bad although not in a league with the Steyr and similar guns.

The main problem is the "variance" of that mean time. While the manual gives an estimated average, in actual use there has been extremely wide variation around that "mean" value, probably due to inferior quality (purity) of the steel itself used for the parts rather than tempering or annealing of the individual parts.

For making spare parts, the optimal material in part will depend on what tools one has for the manufacture. Also, the hardness of the replacement part must not be at a level that they will damage the adjacent surfaces, or be too soft to maintain shape, or too brittle to withstand use. The hammer, firing pin/striker, and springs tended to be the main areas of failure. Aluminum bronze, and beryllium copper also can be used for some of the parts quite effectively.