All, as far as the issue with screwing in the shroud, eventually that issue should be gone, because ARC told me that they planned to go to a tool less design. I saw it on the Mausingfield and the Archimedes. They are consolidating production for what they can across models is what I understand. Doesn't help us now.
I looked at all three of my Nukes, but couldn't exactly see what you all are talking about as far as how far you need to screw it in. I will have to go back through the comments and figure out what you are talking about there.
One thing to note here before anyone goes screaming to ARC about the shroud to bolt body gap causing light strikes... the gap between the firing pin shroud and the back of the bolt *can* vary between bolts-- but unless the shroud is so far back the firing pin can't protrude through the bolt face 0.035" before the cocking piece bottoms out in the shroud and/or the shroud is so far back the locking plunger can't engage the notch in the back of the bolt body, the gap amount between the bolt and shroud in the assembled condition really doesn't matter and shouldn’t be used as an indicator of a problem.
The forward motion of firing pin and attached cocking piece is limited by the shroud so the firing pin doesn't launch across the shop when you remove it from the bolt body-- but only when it's removed from the bolt. The forward movement of the firing pin and cocking piece when installed in the bolt is limited by the castle nut and washer on the front of the firing pin which controls firing pin protrusion.
The amount of rearward movement of the firing pin and cocking piece during bolt cycling is a function of the cocking ramps on the back of the bolt body and also the trigger sear in the closed & cocked position.
The shroud keeps the firing pin, cocking piece, and spring retained when you remove it from the bolt; so the shroud itself can limit the forward movement of the firing pin-- but normally only when removed from the bolt. If the shroud was unscrewed too far from the bolt body when assembling the bolt, the firing pin would not be able to move forward far enough to protrude from the bolt face and ignite the primer as the cocking piece and FP forward motion would be stopped by the cocking piece bottoming out in the shroud. Having the shroud unscrewed too far may also prevent the shroud locking plunger from engaging the notch in the back of the bolt-- so as long as either of those conditions aren’t happening it doesn’t matter if the gap between the back of the bolt and the firing pin shroud is 0.020" or 0.070" when assembled.
The real question here is why both of my actions have around 0.253" of firing pin travel without the influence of the trigger & sear from the bolt open to bolt closed positions (with the FP protrusion set at 0.035") while other people are reporting their actions only have about 0.195-0.205" of FP travel in the same conditions. That “lost” 0.050" of FP travel is robbing the energy needed to ignite the primers reliably. Measuring the FP travel from the back of the shroud to the tail of the firing pin will show a 0.010” difference between LH and RH actions, but that measured 0.010” difference is only because the shroud moves 0.010” relative to the bolt body over 72 degrees of bolt rotation-- and that 0.010” shroud movement between bolt closed and bolt open is opposite in an LH action compared to an RH action. The *total* amount of FP travel from bolt closed to bolt open should be the same between RH and LH actions as that’s controlled by the FP protrusion setting, cocking ramps and cocking piece. Without seeing a "problem" action in person I can only guess as to possible causes limiting the firing pin travel between bolt open and bolt closed...
1. incorrect / too shallow cocking ramp cuts on back of bolt body. However, if the cocking ramps were cut too shallow that could limit the forward FP movement during firing as the cam surfaces on the cocking piece would hit the bottom of the ramps and stop the firing pin before the firing pin protrudes from the bolt face.
2. back/flat portion of bolt body cut too short which would limit FP cocking on bolt opening since that would effectively shorten the cocking ramps. However, this would only limit the amount of FP cocking on bolt open-- with a trigger installed, an action with this issue would probably have a *lot* of overcocking on close from the sear. This condition should still produce adequate FP travel from cocked to fired... unless the sear on your trigger is way too short or you significantly shortened the sear engagement surface on the cocking piece to reduce the amount of overcocking / “bump” on close.
3. trigger pins located too far forward / trigger sear too short / a combination of both. While this would limit FP travel from cocked to fired, it would limit FP travel *only* with the trigger in the system... the bolt itself should still have approximately 0.250" FP travel from the bolt open to bolt closed positions with the bolt removed from the rifle. For example say the trigger sear was 0.075" too far forward; you should see and feel that 0.075" of FP drop during bolt close before the cocking piece engages the sear and catches the firing pin.
4. Firing pin too long or back of cocking piece too short (the surface of the cocking piece that the firing pin tightens against.) If either of these were the case, even if the FP protrusion was correctly set to 0.035", the firing pin being too long or the back of the cocking piece being too short would place the cocking piece further to the rear away from the cocking ramps and sear, so the total amount of FP travel both with and without the trigger would be reduced since the cocking piece would be held further back from the cocking ramps and also from the sear.
Those are a few ideas I had while looking at my actions... and they're all just ideas without being able to look at and measure a "problem" action in person.
I really would like to see the root cause of this light strike issue identified and resolved for those who are experiencing it to satisfy my curiosity… and also because I can only guess at the frustration level for those experiencing it.