This barrel set from Barrel Depot is labeled 3.7cm Flak 37/43 but the Flak37 and Flak43 barrels are different in design with the later Flak43 barrel being slimmer than that of the Flak37. Therefore this set is actually only applicable to the Flak37 barrel as used with the Tamiya kits Sd.Kfz.7/2 (kit #35144) and 3.7cm FlaK37 AA Gun (kit #35145) and consists of a single aluminium barrel with separate machined brass flash suppressor.

Unassembled parts

Dimensionally the flash suppressor size matches the 1:35 plans in Panzer Tracks No.12 Flak Selbstfahrlafetten and Flakpanzer book perfectly but the barrel length is 2mm longer than that indicated in the plans which in turn makes the overall length 2mm to long.

The flash suppressor is the standout part as it is fully hollowed out back past the collar gas holes with cleanly drilled holes in the flash suppressor without any cleanup needed. The only issue with the flash suppressor is the edges of the cone are a little on the thinker side compared to others available.
The barrel doesn't include the collar section and only has a small lip plus the locating pin for fitting to the kit gun receiver, this isn't a problem as you just cut off the kit barrel at the appropriate point.

Image showing flash suppressor with open holes

The fit of the flash suppressor to the barrel was a little loose but when glued in place with cyanoacrylate (super glue) this is no longer an issue.

All that is required to fit the metal barrel to either of the Tamiya kits is to carefully cut off the plastic barrel level with the front of the collar, then drill an appropriate sized hole for the pin on the metal barrel which is then attached to the kit gun.

Fitting the barrel to the Tamiya Flak 37

Assembled barrel on Flak37 from the Tamiya Sd.Kfz.7/2

Comparison of available Flak37 barrels, the white lines
indicate the dimensions as per the 1:35 plans in the
Panzer Tracks No.12 Flak Selbstfahrlafetten and Flakpanzer book.

While the flash suppressor matches the Panzer Tracts plans the cone rim is a little thick and the barrel length is 2mm longer then the plans indicate, other than this it is a nicely detailed barrel that will improve the look of the kit barrels.

Recommended

Thanks to my Credit Card and the guys at Hobby Easy for the review barrel.