This sounds like it is more likely an MEN product than a RUAG product. These white boxes usually show up in the US, and particularly at SGA as production overruns components loaded for cheap commercial sale. A few years ago S&B had a contract with Saudi Arabia for 9mm P headstamped MIC. Less than a year later this same headstamp showed up on “white box” ammo in the US. These had the generic S&B brass bullet, not the GM bullet of the rounds made for Saudi Arabia.
S&B has also, in the last few years, produced ammunition or at least cases for MEN with the MEN headstamp. I think Peter’s point on the Ulm proof house is very significant.
I seriously doubt that the “R” stands for RUAG, but more probably was required by the original customer—whoever he was. I suspect the answer will come from S&B if it comes at all. Still, I have been wrong before as you all know.
In the 1960s and 1970s, DAG, SFM and FN had a mutual agreement to fill orders for each other. None of them produced all calibers all the time. In 9x19, they set up/converted a line when they had a requirement. Occasionally, one of these companies would have a requirement to produce 9x19, but all their lines were busy and they couldn’t fill the requirement, so one of the other companies would produce the ammo with the other companies headstamp. I have two examples of these rounds. One is an FN headstamp from the mid-1960s which is obviously made by Geco/DAG. It had a magnetic bullet and red pa and the headstamp was subtly different. I also have a Geco round obviously made by SFM with the typically brassy color of the case and bullet and the bullet is non-magnetic. Back then I knew someone in FN and asked him about these and he explained the business relationship between the three companies, The new organization with RUAG and CBC owning so many companies, they are much more likely to be able to find one of their own factories that has the capacity to handle these overflow workloads within the company. Still, they may have arrangements to hand off overflow between the two companies.
Just some random thoughts. It is a very interesting headstamp. I hope one of you find out who made it.
Wish I had seen it when it was available. I would loved to have bought a case, or have found at least a cartridge.