It "looks" like it might be a rifle-grenade adapter/sight. What rifle it might be designed for, I have no idea.
I found it. Its for a MAS-49
You know that someone is out there looking for one and can't find it. If you can't use it, you might list it on gunbroker.com .
I have one exactly like it and have wondered what it was for. I got it at a flea market, purchased from an illegal alien. I got the grenade launcher and a WW2 dated Mosin scope and mount for only 35 bucks. Best I could tell from his broken English he picked both items out of somebody's garbage.
Check those dots on the front blade and rear sight. I'll bet that they are phosphorous, tritium or other glowing material and that this is actually a night sight unit. A grenade sight would have the means for very high elevation settings as the trajectory on rifle grenades makes a 45/70 Trapdoor rifle look like a varmint rifle. It does not appear that this unit is capable of high angle sighting.
If it was made in 1971, I doubt that the unit's luminescence functions anymore, but you can check it by taking it outside or shining a bright light on it and then taking it in a dark room or closet. If it is phosphorous, it might glow a bit. If tritium, the half life is just over 5 years normally and its luminescence is probably as dead as the MAS 49 is as a modern battle rifle.
On the MAS 49 grenade sight, there was a hinged sighting bar behind the front sight and when folded up it provided several inches of elevation settings for lobbing rifle grenades out to a couple of hundred meters.
US Military grenade sights have used both a rear aperture and blade/post front sight in one unit, but some countries, including the French used the tip of the rifle grenade as the front sight and with the short sight radius, some extremely high angles of fire could be achieved.
MAS grenade sight folded down along the barrel. The radial grooves on the barrel allowed a soldier to adjust the velocity level of the grenade when fired by aligning the base of the rifle grenade on the desired ring.
Last edited by Scharfschuetze; 10-27-2015 at 12:26 PM.
Keep your powder dry,
Scharf
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |