How to date a mismatch MP40?

[Lewisfan]

The receiver and all attached parts are matching.  The lower parts are all matching. Upper and lower don't match.  

The lower is a bnz 41 date.  The upper has the SN (4-digit starting with "8") followed with an "e".  The only WaA I see are WaA623. Barrel nut is 6-sided and the receiver has a safety "hang the bolt" slot.  Magwell is ribbed.

Is this enough info to verify a manufacturing date?  I assume, based on the WaA that this is a Steyr gun. I'm just curious to find out what year it was made.

[Rekraps]

Pics?

[Rekraps]

Since its the upper receiver that determines the SN for registration purposes, then the SN just forward of the magazine well should be the one on the registration, BUT, the mfg date is on the end cap of the lower receiver, so I'd use that bnz41 as the mfg date on the forms.

I'd love to have an ATF person comment on this. 

[MS Collector]

Here is my bnz41 (#9846e).  Given that your receiver tube and barrel is Steyr (623 proofed) and in the "e" block as well, I'd say it is from a 1941 production gun.  It would be interesting to see how far off the lower is from the upper.

[Lewisfan]

Lower is a bnz 41 date with 3 numbers and an "l" (same as pics that you posted).  Question remains - how to date a receiver without a matching lower?  

Another note is that even though the matching barrel / barrel nut have the 6-face nut (vs later 2 "flats"), the receiver does have the creases top and bottom at the trunnion.  I read another recent post that states this was done on "later" guns as a more efficient method to press in the trunnion. Although the same post notes that this usually is seen with the 2-face barrel nut (also supposed to simplify production).  Any clues to date the receiver are appreciated!

[Rekraps]

8 hours ago, Lewisfan said:

Lower is a bnz 41 date with 3 numbers and an "l" (same as pics that you posted).  Question remains - how to date a receiver without a matching lower?  

Another note is that even though the matching barrel / barrel nut have the 6-face nut (vs later 2 "flats"), the receiver does have the creases top and bottom at the trunnion.  I read another recent post that states this was done on "later" guns as a more efficient method to press in the trunnion. Although the same post notes that this usually is seen with the 2-face barrel nut (also supposed to simplify production).  Any clues to date the receiver are appreciated!

I don't think you will be able to do so. The Germans used a four digit plus letter production code that repeated each year. Unless you have the matching lower with matching SN, you will not be able to do so. So, find the Lower!

[TSMGguy]

Right. All that can be said of the lower in question is that it was made by Steyer. Good photos might yield other clues.

[Rekraps]

16 hours ago, MS Collector said:

Here is my bnz41 (#9846e).  Given that your receiver tube and barrel is Steyr (623 proofed) and in the "e" block as well, I'd say it is from a 1941 production gun.  It would be interesting to see how far off the lower is from the upper.

My all matching bnz41 is same month production, only about 200 off from yours!

[Wolfenzapf]

On 4/3/2024 at 1:48 PM, Rekraps said:

I don't think you will be able to do so. The Germans used a four digit plus letter production code that repeated each year. Unless you have the matching lower with matching SN, you will not be able to do so. So, find the Lower!

A bit late reaction but this is incorrect. Erma for example did NOT use a serial number that repeated every year. They continued their serial numbering from 1939 till 1943. (No yearly restarts) Only after the initial 1938 production (for the MP38) they restarted their numbering in 1939. 

Edited July 9, 2024 by Wolfenzapf

[tommyboy]

The receiver usually has the last two numbers of the year marked next to the letter code of the manufacturer of the receiver. These will be located underneath and in front of the magazine well. In the case of this Erma (AYF) gun, the manufacturer of the receiver was Merz Werk with a subcontractor code of “COS” and a “44” date.

[Rekraps]

More info for me! I'll pull mine later and check! 

thanks.

[Buzzbomb]

On 7/9/2024 at 11:42 PM, tommyboy said:

The receiver usually has the last two numbers of the year marked next to the letter code of the manufacturer of the receiver. These will be located underneath and in front of the magazine well. In the case of this Erma (AYF) gun, the manufacturer of the receiver was Merz Werk with a subcontractor code of “COS” and a “44” date.

Interesting as that does not look like the German number 4 stamp used at the time. Look at other examples of a German 4. Can be seen in the other poster images above. 
 

could be wrong though. 

[TSMGguy]

9 hours ago, Buzzbomb said:

Interesting as that does not look like the German number 4 stamp used at the time.

Looks right to me. The die was being held slightly off the vertical when it was struck, resulting in a light strike of the first 4.

[Lewisfan]

No numbers on my example. The serial is stamped and then on the barrel the last 3 plus "e" of the serial number are stamped.  

[Buzzbomb]

3 hours ago, TSMGguy said:

Looks right to me. The die was being held slightly off the vertical when it was struck, resulting in a light strike of the first 4.

It lies more in the shape/font of the 4. 
here is a pic of my mp40 by bnz 42. 
 

note the font of the 4 is different  

 

[Buzzbomb]

Actually. It does kind of look the same haha. Who knows. 
 

what I do know is mine is not draped with a date under the trunnion area.