Threaded Barrel

[CraigH]

Some 15 years ago or more upon my first return to air guns, I began to see aluminum breeches from a few vendors.  I had asked about making a breech for a threaded barrel but no one was prepared to make one.  With my complete misunderstanding of the air (or CO2) path I wondered why.  I subsequently returned to firearms and cars.

Well, fast forward to my second return to air guns and now membership in CAPOF.  After thinking about having a threaded barrel and breech again it seemed possible, but withe a few concerns.  The main thing is a barrel once fitted to a breech is quite unlikely to fit another breech and any desire to change to another barrel will required another fitted barrel.  But regardless, I have not thought a grub screw the best method of attaching a barrel to a breech.  At least it's better than the unattached barrel to plastic breech.  And the grub screw does serve rather well and easy to use.

So here is the threaded breech and barrel.  A few discussions with Rich (arkmaker) brought us to understanding what I wanted and he made the breech.  The project stalled for a while as after a couple of mini-lathes RMA's I was and still am without a lathe.  So I just decided to do a hack job with file and mid-size drill press.  It is not the best work, but it is fitted and the bolt latches nicely with a Discovery probe.

The barrel was a 7 inch 2240 now at a small amount over 6 inches.  The muzzle was cut back at the sight flat and the breech end cut to remove the TP and the chamber so it could be threaded and fitted.

There is not a lot of material to work with; it could be very nice with a raised breech (which I would like with a free floated barrel) and a heavier barrel the latter of which would give more thickness for the TP port.   (Also use a lathe!)

[1377x]

Sweet. At least there won't be any slop.

[KevinP]

COOL  ...   

[CraigH]

I should have mentioned that the chamber is a conglomeration of what I measured, the drawing from JMJinNC, and what I had at hand to make it.  And a lot of cut and fit until it was good.

[BillK]

Looking good! 

[ped]

if it was me (and I've a daq .25 sb threaded barrel to make a breech for when I get time) I'd have made it so the port was in the breech rather than the barrel and the barrel just screwed in
I've a couple of Alros tdr rifles that do it this way

[1377x]

That's a good idea ped

[CraigH]

And since the breech has to be made for the barrel, as opposed to off the shelf, I supposed the TP could be integral with the breech and just use an appropriate seal.  The bottom of the Crosman breech is not very thick though.

[Rualert]

      Another option would be a thimble of sorts for the TP/loading port. You could adjust the length to index the barrel, and the threaded barrel would compress against the thimble for a nice tight fit. Just a few crazy thought that hit me when I read your post.

Casey

[CraigH]

All thoughts are good and welcome, Casey (and others)!  This is a sort of proof of concept for me since I thought there must be a better way (not easier, at least for me).  Of course adding more set screws to hold the barrel is a lot easier - I use three on a long breech - would use two, but Crosman places the single screw in the middle of the breech top.