Making a blank-firing barrel for the PPSh-41
I took an old 7.62x25 barrel, rechambered it for 9mm. Threaded the muzzle 3/8"x 16".
Used a
3/8"x 16" set screw and drilled out the center. Set screws are very
hard to drill, so my son made a jig to screw in the set screw to make
it easier to drill. Some have said they put the screw on a brick and
then heat up the set screw to a dark red and let it cool. This makes
the steel softer and easier to drill. (I tried this and it really made the drilling easier.)
Got
an e-mail suggesting putting the set screw in the barrel, then drilling
the set screw hole with the barrel in a lathe. Also a good idea.
The table shows the hole sizes and the cyclic rate of my Russian PPSh-41:
(7 rds. shot in a drum on a 40ºF/ humid day)
Hole diameter |
WW2 |
Fiocchi |
AtlanticWall |
|---|---|---|---|
.125" (1/8") |
1318 rpm* |
1224 rpm |
- |
.156" (5/32") |
1111 rpm |
880 rpm |
- |
.161" (20)
| 1002 rpm |
805 rpm |
956 rpm* |
.166" (19) |
920 rpm |
777 rpm |
- |
.171"(11/64") |
791 rpm* |
- |
866 rpm* |
I prefer the .161" or the .166" holes. Ejection is good and cyclic rate seems more like the PPSh. The .125" is way too fast, the .171" hole cyclic rate is too slow and ejection is not very good, only about 2" height. Atmospheric conditions can affect the cyclic rate. Smaller hole in the winter and larger one in the summer. The Fiocchi factory 9mm blanks produced about 190 rpm less for each set screw restrictor than the "WW2-Blanks" brand. I've been told many reenactors swear by the Fiocchi factory 9mm blanks, but my preference is for the "WW2-Blanks". The "WW2-Blanks" are made from Win 9mm Mag brass. They are no longer making 7.62x25 blanks, even though the website still shows them available. I would recommend buying a small quantity of each manufacture and try them in your weapon to see which one you like best. I bought some 9mm and 7.62x25 blanks from "SJZ BLANKS" which proved to be very hot. They would not function in my PPSh at all. So hot that the brass case would expand and not extract from the chamber. The problem I found, was that the "star" crimped end was so tight, that it could not open upon firing and the pressure would expand the case. After using a 1/16th inch drill, opening the tip and resealing with some Elmer's Glue, the blanks would work fine.
Today (2008), many reenactors are using the cheaper, short Czechoslovakian ("bxn" headstamp). These do not work in the PPSh-41 due to the short length. I've been told they work in the MP40 and PPS-43 satisfactorily. Only the more expensive full length blanks must be used in the PPSh-41. (They feed better in my drum than the stick magazines.) The upside is that the newer full length blanks are usually non-corrosive, whereas the short Czech blanks are corrosive.
Nartron blanks (Fiocchi)
AtlanticWallBlanks
Joe Swanson blanks
WW2-Blanks
Blank-firing guns
Threaded muzzle
Set Screw