Bolt identification

[ssgshooter]

I have two bolts (complete) that I’ve had for about 12 or 13 years in the bottom of my parts box, but I can’t remember where I got them, or who makes them. I think I picked them up at a show in New York.

They look like there in perfect condition, and are marked MPF. Does anyone know who makes them, and if it would be in working order (spring) since it's been sitting "forever"???

I wanted to put them on an auction site but I wanted to get some info on them first.

Any help would be appreciated!!

[tweakmeister]

I believe these are FN.

The springs are probably fine. Note the latest "spec" is a 5 coil (not 4) spring with black insert (not blue) with Crane O-ring. Bravo company sells a nice upgrade kit 3-pack for $12.