for decades Krieghoff/Ulm was making insert barrel for shotgun barrels in 12 and 16 ga

called EL 22 for the 22 cm long "Einstecklauf"

and EL 44 for the 44 cm long barrel

muzzle velocity betwenn them was only +/- 15 - 20 m/sec difference so the short barrel is enough
they were made in 22 lr and 22 mag but the 22 lr is more common

there was also another version for the old 5,6x35R Vieling

this short inserts are not realy liked here today because adjustment is tricky and you buy the short .22 for 30-50 euro. with time and patience you get them on the target and I have shoot into a 20 mm circle at 50 meter.
I had the upper one here for a long time but the extractor was making problems so I take another one from an estate for 35 euro.
first I did not notice there was a difference because dont hold them side by side.

when taking the new thing for a test I see it was not the common system and when looking on the barrel I notice it was marked with "Sempert & Krieghoff Gewehrfabrik Suhl".

so they making them before the war, never know it.

Cal.16 - 22 lfB DRGM
22 lang für Büchse (lfB) means long rifle and DRGM is Deutsches Reich Geschütztes Modell (registered design)

there are little differences beside of the shorter 20 cm long barrel but even the special wrench fits

dont know how using this part for adjust the insert, the post war barrels have sliding points

raccons as an invasive species became a real pest here and when I got a call last week to help an old woman were they make trouble the new .22 got first work to do.

two at once in the trap and the 16 ga shotgun barrel work like a silencer for the .22 subsonic from the short insert. its maybe loud like a good airgun - just perfect.

have a ppk for this but shooting game in the trap is most times near the next village so its not a good idea to use the extra loud 7,65 mm from the short barrel at 6.00 a'clock in the morning