Despite the incredibly crappy etch-a-sketch MS FingerPaint drawing
, we do understand what's going on with your hammer/striker situation. If the striker in this gun design is able to rotate, then slightly rounding off the edge of the end of the striker will allow the hammer to hit the very center of the end of the striker, no matter what position the striker is rotated in. If the strike is prohibited from rotating by design, then the end of it may be rounded to a simple radius in the transverse vertical plane only. Just make sure not to take any meat off the center area of the end of the striker, or that will shorten it, which may change things a bit in terms of protrusion (assuming this strike is integral with the firing pin farther forward.
In the configuration as it presently is, the hammer contacting low on the striker may have a tad less force, and may even result in some force pushing the end of the striker upwards instead of all the force applied in a direction along the center axis of the striker. This is really a simple exercise in geometry and force vectors. Ensure that the striker is polished very smooth, even mirror, along with all other parts that slide, so you reduce friction to a minimum. If corrosion is an issue, blue the parts after polishing them mirror smooth, so you form a magnetic (oxide) layer that holds oil, hence no steel will be in contact with air (and thus moisture) and rust orange on you.
The problems with ALL semi-auto conversion I have seen are:
1) a reduction in recoil spring strength from cut/downsized recoil spring, resulting in much weaker feeding force to push the round out of the tight belt links and into chamber,
2) increase friction due to more surface area of sliding parts in the modified design, and
3) heavier firing pin/striker mass requiring strong hammer force so military hard primers are struck hard enough to fire reliably. A solution may be a combination of a heavier hammer spring with a heavier hammer. AR-15 guts don't seem adequate to solve the problem. Also, the AR-15 parts can break after a time. (easily replaced).
A legal full auto MG-42 is much more simple and reliable, but as we all know, they are ridiculously expensive and really eat your wallet in ammo costs, even though the sound they make is FRIGGIN' AWESOME.
I dinked with my buddy's semi auto M-53 enough to get it fairly reliable, but it still doesn't slam that bolt forward with the speed and force of an original MG-42, which makes me cross my fingers every time we run it.