Thursday, May 14, 2009

Making a Steel Breech for a Crosman 2240, Part 1

I picked up a Crosman 2240 air pistol a few months ago at a pawn shop. I decided it would benefit from a few modifications, the first of which is a steel breech. So here I go:

Some 1" Free machining steel was chucked true in the 4 jaw chuck.

I drilled down 2" with a long drill bit...

Then a slightly larger drill bit...then repeated until I was in about 4"

I reamed the hole 1/4"

Flipped the work and repeated the step drilling to the proper depth for the barrel.

And reamed to 7/16"

Unchucked my tube from the lathe and started milling.

One side done.

Flipped and the other side milled.

Flipped again...

Now my tube is a rectangle. Why didn't I just start with rectangular stock? Because I wanted to use free machining steel and I didn't have any square on hand.

Finding the edge.

Milling a step as preparation for the dovetail cut.

The other side step cut.

Milling the dovetail.

Almost looks like a breech.

The Taig won't handle a 7/8" diameter end mill, so I had to use my Barker horizontal mill. I aligned the work on the table.

And cut the radius groove. My Barker is pretty worn out so I got a terrible surface finish, the table was slewing back and forth during the cut as the rack feed must have about a 1/4" of backlash. The next breech, I'll line bore on one of the lathes, but for that I'll have to rig up a milling attachment and single point between centers bar.

4 comments:

Bruce said...

I'm really enjoying your blog. I have an old 1377 and I'm looking to make a steel breech (and other assorted components) to replace the original sliding loading-port cover and plastic breech. What is a reasonable wall thickness in the breech part between the .75 dia pump tube and barrel od (space between bbl and pump tube)? Also, approx how deep should the barrel be supported in the breech? I have an old Atlas 8-16 lathe and a small drill press. Thanks!!

Felice Luftschein said...

Well I'm hardly an expert as this was the first breech I've made, I basically just copied the same distance between barrel and tube as the Crosman breech uses. For depth I wanted to not need the barrel band so I went long w/ the two setscrews, but it could certainly be no longer than the original if you use a barrel band.
Good luck!
Nick

RifleMasters said...

haha...DAMN man...thats a killer mod you got goin on there. how and where the hell did you learn that? online somewhere or just screwin around?

Ron Benda Jr said...

Would you be willing to build a custom breech as long as you were paid for your time and labor?