Sunday, October 26, 2008

Getting a Crosman 140 Working, Part 4

Now to make a new bolt.

Turning some stock down to 5/16"

Turning some steps on the bolt nose.

Blurry pic of making the o-ring groove.

Drilling the end.

I used a file to chamfer the end and the lip that holds the o-ring on.

Flipped with the waste parted off.

Looks pretty close.

Spotting the flow-through port in the bolt nose. Notice the orientation of the hexagonal collet holder.

Drilling to size.

The collet holder is rotated 30 degrees in the vise. Notice the old bolt being used to make sure I get the alignement correct between the bolt screw and port...

Drilling the bolt screw hole.

Tapping the hole.

Old bolt, new bolt.

Turning up a new transfer port seal out of urethane.

I ground a new toolbit for rubber, an extreme rake angle, more of a sharp knife edge. Worked well and gave a nice smooth cut.

Put the 140 back together and found that I gained about 15 fps, to 595 for 10 pumps. Still a little slow, which may be because of the pump cup having too much headspace.

No comments: