Saturday, May 16, 2009

Making a Steel Breech for a Crosman 2240, Part 3

Almost done...

About to mill the slot for the bolt handle.

And milled.

This is a rather convoluted setup for milling the bolt catch. The breech is tilted on its side 30 degrees.

The slot cut.

A Crosman bolt (from their steel breech) fits perfectly.

Again, the rough finish.

Assembled on the 2240 to check for fit and function.

Now to do something about the finish.

An aluminum rod was turned up to be 7/8" diameter minus the thickness of some sandpaper. I used it to sand the radius smooth.

Looks much better.

I was going to lap the sides against sandpaper but then I remembered that I had a surface grinder! So I started to grind the sides.

I probably removed about 2-3 thousandths on each side.

Grinding the chamfer on the bottom.

Shiny, now I regret not making it from stainless...

A 220 grit Scotch-Brite Bristle Disc on my polisher.

I deburred and smoothed. You can see some sandpaper wrapped around a file just above the breech. I used it to smooth the breech cutout and the dovetail surfaces. I still see some faint milling marks but I'll live with those.

Another view. I tapped the two holes for the barrel setscrews.

I turned up an end plug.

And made a decorative series of grooves in the face.

I blued both with Oxpho Blue. I'm going to see if I can get it darker.

You can see reflections in the breech. Now I need to work on the bolt and bolt handle as well as figuring out what length barrel to use. But not bad for a first breech?

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