Thank you for all that information! It sounds like your very well rounded in the Action market! I do hope the CDG gains a prefit barrel market. If Proof offered one, I would have never needed to post this thread and would have just gone with the CDG&proof! lol.
It seems like you have a very diverse accumulation of actions; If you don't mind me asking why not have the Impact 737r in your collection? I am sure you have some experiance with it
I do have an impact 737 cut for AW magazines in the safe which I mentioned... It's a very nice action, works well, and there's lots of prefits available for it, but I prefer the overall feel of the bolt cycle on the Archimedes. Not that the impact is bad or rough (it's a very nice action) but the Archimedes is just smoother imo.
The impact can run double stack AW mags though, while the Archimedes can only run single stack AICS mags, and given the choice I'll always get an AW cut action and run an AW mag if possible as they're shorter and much easier to load than single stack AICS mags. Sometimes the AW mags do need some adjustments for latch height to work well with your particular action and stock/bottom metal/chassis combination, while the single stack AICS mags are more forgiving with R700 style actions.
My Archimedes is in 223AI, and only single stack mags are available for 223, so the single stack only Archimedes is perfect for that. I have 2 more Archimedes actions in the safe that will probably get used for a super light 223 build and a lightweight hunting oriented 7 PRC build, and again, only single stack mags are available for those calibers so the Archimedes will work perfect.
I picked up the CDG for my 22GT build since I can use AW mags with that caliber. I was initially planning on using my spare short action Archimedes for the 22GT but as soon as I saw the CDG supported AW mags I decided to use that instead.
I don't think you can really go wrong with any of the choices out there. The impact is really, really popular right now, so tons of places offer prefits. The TL3 and Origin are nice too, and offer inexpensive swappable bolt heads if you ever wanted to change to a different bolt face in the future, compared to the impact where you have to buy a complete bolt. I believe the origin is AICS single stack magazine only, you have to step up to the TL3 to get one cut to run AW mags. There's nothing wrong with the single stack AICS magazines, but once you use the shorter and easier to load double stack AW mags it's hard to go back.
Does the cocking piece = top sear?
If so, I imagine one has to remove the trigger each time to file off a little more?
I’ve never done what you suggest as I have been using Bix ‘n Andy TacSport Pros and seem to have had decent luck. I just order the correct top sear for whatever action. Certain actions could be a tad smoother, however, when compared to the same action and same trigger.
So you’ve gotten me curious to try to refine the top sear engagement on a variety of my rifles, including the ones with BnA triggers. I somehow thought it was black magic.
Sear height is different than trigger timing. If the sear is too tall you can have excessive cocking piece drag across the top of the sear which can lead to firing pin drag and light strikes. Too low and the sear engagement with the cocking piece might not be adequate and the firing pin might fall if you drop or bump the rifle or wiggle the bolt handle.
Timing is adjusting the forward/aft position of the cocking piece or trigger sear surface, typically to ensure zero cock or decock on close for a 100% cock on open action for the smoothest possible bolt closing. You can do that by removing material from the sear on the trigger or sear interface surface on the cocking piece attached to the firing pin, or moving a trigger hanger forward or aft.
The impact has some cock on close by design so trigger timing isn't as critical to the overall feeling of the bolt cycle, but for a 100% cock on open action a properly timed trigger with zero overcocking on close can make a big difference in the overall bolt feel during closing.