LTM to M mount adapter with Leica M6 question please

I have Leitz manufactured adapter to mount LTM lenses on M cameras. It is marked M2 50 M3 28-50. I have used this with good results on my M2 and M3 cameras. I have NOT used it on my M6 camera.

I wish to try out some different LTM lenses for fun using my M6 body.

Questions please: 1. Can I use this adapter with my M6 body?
2. Is it safe to use the Russian Jupiter-12 35mm lens with the Leica M6? I worry that the extended rear element group will impact or damage the shutter or metering parts inside.

All the other lenses are conventional LTM lenses. The Jupiter-12 concerns me.

With thanks,
Sam H

Hello Samuel,
Leitz manufactured several LTM to M 39 mount adapters for different focal lenghths. The difference between them is not the register but only which viewfinder frame is visible when the adapter is mounted on the M Leica. If you mount your adapter to an M 2, you'll see the 50 mm frame (the M2 has frames for 35, 50 and 90 mm). On the M 3 you'll see the 50 mm frame too (the M 3 has frames for 50 mm, which is always visible, 90 and 135 mm). On your M 6 it depends on which model you have, an M 6 -0.58, -0.72 or -0.85. Most probably you have a 0.72, then you see the combined 50/75 mm frames.
Between the rear lens and the shutter is a lot of space and no mirror. Even the old 3.4/21 mm Super Angulon can be used on the M 6. The rear lens is only 3 to 4 mm away from the shutter but the barrel shades the light metering cell, so you cannot measure but you can take pictures.
Have a look on your Russian 35 mm lens how long the rear lens protudes, I'm sure you'll habe no problem from this side but you'll see the wrong frame. An M 2 35/135 mm adadpter or an M 3 135 mm adapter would be better. But if you set the focal length lever manually to 35 mm, you can take pictures.
Only the M 5 and the CL had restrictions for old long protuding Angulons, Super Angulons and collapsible lenses.

Good morning Jochen,
Thank you for your well informed answer sir. I feel much more comfortable now hearing this.
Sam H.