Mine is a JM model 30/30. Tried all the usual fixes.

I still have one for a 1895. I had an 1895XLR that showed no problems until I could not get it to fire at a buck. I put it in the gun but also removed burrs on the edges of the firing pin channel of the bolt. I removed it when I sold the gun but still have it somewhere in my parts bag.
The issue with them is that they eliminate the safety mechanism that prevents firing if lever is not fully closed.

Soaked the stripped bolt for days and used a brush and pipe cleaner. Can't be that.
New main spring and two washers.
New rear pin
Everything smoothed up
Changed lever
Took hammer spur off
Mostly concerned with poor headspace even though the pin can be pushed to outer bolt rim.
Sized brass on shoulder
Tried different primers
Tried different brass trim sizes
Took it too a mediocre Smith 3x, no joy