My 375 Mercenary /400 Warlord build is on a Pierce action, being built by the man himself, Mr. John Pierce ....
probably the strongest action for the 375 CT sized cartridges,
I would agree that waiting on Bertram brass is an exercise in futility, we wasted nearly 2 years of time with that awfully weak brass and are now back to square one with the 375 Mercenary cartridge, after personally testing and burning through 100 pcs of brass in a once fired and throw away scenario and receiving multiple reports from pissed off shooters, we concluded the Bertram made 375 Mercenary brass was a one use prophylactic, you shoot once and dispose of it, we reached out to Bertram to correct the weak brass issue so we can initiate a second run of brass but no response was ever received and concluded that he wasn't interested in replacing his defective product, the take the $$money$$ and run was a sad state of affairs, but we are moving forward after that terrible, yuge unneccesary easily correctible (by an honorable and responsible mfg) setback
as such, we will be having super tough brass made here in the United States, getting my finances in order after the new year and will have a batch produced for myself and a few local guys with completed and ongoing builds,
Once the brass is tested and we are satisfied, I will release the 375 Mercenary to the public domain where everybody in the world has access to the reamers, prints and brass... and that included the 338, 408 and 416 Mercenary cartridges as well
Pro Martusheff