Erma .22 coversion kit for 9mm P.08

ithacaartist · 01-25-2012, 05:03 PM

A recent auction purchase arrived the other day, a post war .22 conversion kit. The auction was a relatively small one, available online; the lot listing was a little obscure--I almost went by it without reading further, but had that "Hey, waaait a minute..." feeling about it and clicked to see the related pic. Bingo!

The box is the green cardboard variety, sound and fit. Its only detraction is the stained area inside the lid, where someone had Scotch-taped something, perhaps the instructions, now gone. The kit is comprised of the barrel liner with its nuts and spacer, the breech block/toggle assembly which takes the place of the P.08 breech block and toggle train, and the conversion mag. There is accommodation inside the box for, I think, the .22 cleaning rod, which is missing.

2 issues.

First, and the more annoying, it will not fit and function correctly. The slots milled into the inside lengths of theP.08's barrel extension allow the breech block to slide back and forth. On the left side, the sear makes its appearance midway in the slot, and protrudes from the upper left rail into the assembly to engage the catch on the firing pin when the breech block is returning to battery, thus coc*ing the gun. The catch on the firing pin on either original or conversion breech block is located in between the end-to-end parallel rails on the block's left side, which guide the block in the barrel extension. These rails are supposed to straddle the catch on the sear, so the block whiffs past the sear except for when the catch on the firing pin is encountered, in which case it would spring/slip by on the way back, and the two catches would catch on the way forward. Got it? Anyway, the lower rail on the conversion breech block's left side protrudes too far up and the top, inside corner of it takes up a bit of the space needed for the sear's catch to ride by the breech block's rails without touching them.
So, like the old movie title, something's gotta give. Removal of material would be indicated, so I need to decide whether it's coming off the rail on the breech block that bumps into the sear's catch, or from the bottom end of the catch itself, maybe some from each.
My instinct is to work on the accessory rather than the gun, which is a refinished DWM 9mm 1917/1920 military with a force-matched bbl., a shooter. I will try the kit's block in the top ends of my other Lugers to check for fit, but I suspect the kit as the main offender.

Second, the minor annoyance is that the mag is not particularly held in by its catch, seems a bit loose overall. Push the mag in, it sorta clicks into place; turn the gun upright and give it a shake, and bloop--out comes the mag. I thinking a shim applied to the mag in the appropriate spot may do the trick. I've noticed that the dimensional difference between mag well in a 9mm P.08 and the .22 lr round is taken up just about entirely by the thickness of the mag's walls! And that the radius of the mag's rounded side seems less than what would nicely fill the well in this area.

I welcome any comments, questions, or guidance.

David Parker

01-25-2012, 05:03 PM	#1
ithacaartist Twice a Lifer Lifetime Forum Patron Join Date: Mar 2011 Location: Atop the highest hill in Schuyler County NY Posts: 3,368 Thanks: 7,432 Thanked 2,610 Times in 1,378 Posts	Erma .22 coversion kit for 9mm P.08 A recent auction purchase arrived the other day, a post war .22 conversion kit. The auction was a relatively small one, available online; the lot listing was a little obscure--I almost went by it without reading further, but had that "Hey, waaait a minute..." feeling about it and clicked to see the related pic. Bingo! The box is the green cardboard variety, sound and fit. Its only detraction is the stained area inside the lid, where someone had Scotch-taped something, perhaps the instructions, now gone. The kit is comprised of the barrel liner with its nuts and spacer, the breech block/toggle assembly which takes the place of the P.08 breech block and toggle train, and the conversion mag. There is accommodation inside the box for, I think, the .22 cleaning rod, which is missing. 2 issues. First, and the more annoying, it will not fit and function correctly. The slots milled into the inside lengths of theP.08's barrel extension allow the breech block to slide back and forth. On the left side, the sear makes its appearance midway in the slot, and protrudes from the upper left rail into the assembly to engage the catch on the firing pin when the breech block is returning to battery, thus cocing the gun. The catch on the firing pin on either original or conversion breech block is located in between the end-to-end parallel rails on the block's left side, which guide the block in the barrel extension. These rails are supposed to straddle the catch on the sear, so the block whiffs past the sear except for when the catch on the firing pin is encountered, in which case it would spring/slip by on the way back, and the two catches would catch on the way forward. Got it? Anyway, the lower rail on the conversion breech block's left side protrudes too far up and the top, inside corner of it takes up a bit of the space needed for the sear's catch to ride by the breech block's rails without touching them. So, like the old movie title, something's gotta give. Removal of material would be indicated, so I need to decide whether it's coming off the rail on the breech block that bumps into the sear's catch, or from the bottom end of the catch itself, maybe some from each. My instinct is to work on the accessory rather than the gun, which is a refinished DWM 9mm 1917/1920 military with a force-matched bbl., a shooter. I will try the kit's block in the top ends of my other Lugers to check for fit, but I suspect the kit as the main offender. Second, the minor annoyance is that the mag is not particularly held in by its catch, seems a bit loose overall. Push the mag in, it sorta clicks into place; turn the gun upright and give it a shake, and bloop*--out comes the mag. I thinking a shim applied to the mag in the appropriate spot may do the trick. I've noticed that the dimensional difference between mag well in a 9mm P.08 and the .22 lr round is taken up just about entirely by the thickness of the mag's walls! And that the radius of the mag's rounded side seems less than what would nicely fill the well in this area. I welcome any comments, questions, or guidance. David Parker