Not going to hurt anything, but what's the purpose of doing it? I understand some Bulgarian (I think) made SKS rifles had a problem where they were cooking off several rounds as they were being chambered due to extreme heat retention. Essentially, a three shot burst semi-auto rifle! They were using Ruskkie crap ammo, too, so could be primer/powder related. Got someone's attention.
The only reason why the SKS can "slam fire" is if the owner does not clean it.
There are many firarms with a free floating firing pin (The M1 garand, M1 carbine, AK47, etc.). Again, it was nothing wrong with the design, it was that people were not cleaning regularly after shooting or they didn't clean it properly after they bought it, so it was filled still with cosmoline.
No return spring on a Model 94. Mine is 1976 vintage in .30-30. Surprised me after being used to pistols with inertia firing pins for so long. No problem with it at all, but at first I thought something was missing. After all, it is the iconic American hunting rifle design.
I'd actually be interested to take a look at that design. Maybe I can play with one at some point.
I'd be interested to know how safety is achieved using commercial primers.
Have you explored whether the firing pin is able to "bump" against the primer during chambering?
It probably helps that the gun is a manual repeater, which means the bolt moves relatively slower than autoloaders, which is where most issues with un-sprung floating firing pins seem to arise.It's not. Normal seating is no further than flush with the front of the block with the hammer down as you work the lever. There is enough resistance that it takes a firm strike on the firing pin to punch the primer. When working the lever, the pin comes back and extends into the rear of the block about 1/8". Even if flush at the rear, the hammer inertia fires the round. Has worked for Winchester for over 145 years, so I guess they knew what they were doing. Half cock is the only safety on my model, which I like.
Get one. Model 94 is the most beautiful rifle ever made, imo. Only the Hi-Power matches its elegance. Just my 2C, but I've wanted one since I had a toy "Winchester" when I was about 10. And nothing wrong with a .30-30 for PD in a short barrelled lever gun.