Originally Posted by
44man
The firing pin on the 760 and 740 do not have pin springs but are NOT inertia pins. There is no gap at the back of the pin when the hammer is against it. Yet the pin will blow back and take the hammer back from internal pressure. That leaves a hole for the cup to flow into. The pin on these rifles should be long enough to keep the hole blocked unless the hole is large.
When the pin is pulled all the way back, it should be flush with the bolt face.
The reason a 740 will not slam fire is because the pin does not get a running start, unlike an SKS that will with a thin primer cup. I have turned SKS and AK pins for a spring and stopped slam fires with our primers.