I decided to refresh this thread given new data.
There seems to be a general correlation between BLM (Lubecker) and these Circle A rifles for lack of better term.
The serialization appears to be the same BLM font and the existence of multiple barreled actions completed at BLM is encouraging.
Some general thoughts as to what these are:
1. Very limited production
2. Some saw wartime service (ie. RC examples) so I would make the general assumption that these were produced during the war.
3. If BLM connection then perhaps a cleanup run of serviceable rifles made out of rejected parts.
4. If not BLM, then assembled from parts supplied by BLM and others.
5. Assembly period estimated in 1942-1943 period.
Also, if the owner in Georgia of the initial rifle in the post would contact me.
You could easily think that these K98k with scrubbed receiver and “circle A” are some postwar rework, similar like the rifles from Yugoslavia and the “circle A” is a non German marking.
My thought is, they were assembled/reworked in Germany during the war and you are right with your assumption.
Before I go deeper into this topic, a explanation about the “circle A” marking for rejected parts.
I often read the German word "Abgelehnt", "Ausschuss" but I think it's wrong, even when the meaning is the same. In my opinion the correct word is “Ausgesondert” and you can translate it with
“reject”, “segregate” or “separate”. In the German army we still use the term “aussondern”, I did this action in the armory with defective/unserviceable material like worn out machine gun barrels, magazines, flak jackets etc. You use the word “Ausgesondert” also when you lead intact or even new material or weapons to a new destination.
Some "circle A" facts:
All reference sample which I know have Berlin-Lübecker receiver, between 1938 – 1940 and they have the typical feature, the sequence/batch number on the lower surface of the receiver ring.
All reference sample which I know have “BLM” barrels between 1937 - 1938. The barrel codes are between “37 R 47” and “38 R 60”, they all have the “circle A” marking close to the barrel code.
Until serial number “2824” they have scrubbed receivers, the manufacturer code and “Mod. 98” designation got removed. One K98k has a “circle A” on the right side of the scrubbed receiver ring, where usually the final acceptance would be.
On the place of the receiver and the barrel where usually the firing proof is located, you find instead the “circle A” marking.
With serial number “4011” and the following rifles appear a change. The receivers are not scrubbed anymore, the manufacturer code and “Mod. 98” designation are present. The not scrubbed right side of the receiver ring is blank, without final acceptance. The final acceptance e/214 is instead on top of the receiver ring, usually they start with it since duv 42 production.
On the receiver and barrel is the normal nazi-eagle firing proof, not the “circle A” anymore.
I agree with you, the estimated assembly period is in 1942 – 1943, for many reasons.
Limited production, I assume around 5.000 rifles. The highest serial number which I know is 4990.
I'm still not sure about the purpose of these “circle A” K98k. You know, the German proof law is strict and every weapon, irrespective if military or commercial, they need to have the proof fire testing, there was (usually) no exception. But how the “circle A” is applied on the receiver and barrel instead of the firing proof, it looks like some kind of acceptance.