For those wondering what a steel breech is, and what it does, the following is an attempt at explanation...
Steel Breech in front, and stock plastic breech at rear.
Detail shot showing the 3/8" dovetail groove of the rimfire type.
This is the best method I have found for getting a decent scope onto a Crosman air-gun.
If you are like me, and mod for power, the plastic breeches end up tearing at the transfer port hole.
There is not a lot of material on the bottom of them.
To begin dis-assembly, first make sure the valve is discharged.
The compressed air coming out of the barrel has quite a knife edge to it, and serious injury is possible.
I simply point the barrel at the floor, cock the gun, close the bolt, and pull the trigger.
The screw in the photo above should come out first.
Cock the gun, and the sear will hold the bolt back while this screw is removed.
It is fairly tiny, and really doesn't bear much of a load.
It is a hex socket head screw, and allen key diameter size is less than a single millimeter.
.5mm, IIRC.
Loosen it with the short end of the allen key.
After it is broken loose, the long end of the key may be used for ease in backing it out.
These socket head holes strip easily, especially if the ball end of the key is used under force.
Tightening and loosening should be done only with the short, non-ball end.
After the screw is out de-cock the gun.
I usually hold onto the open bolt handle, pull the trigger, and ease the bolt closed, rather than dry firing against an empty valve.
Remove this screw....
...and lift off the rear sight assembly with it.
Carefully lift the barrel and breech upward as shown.
The barrel is a friction fit in the front band.
It is removed rear-ward, taking care to avoid the transfer port and hammer pin.
The barrel is also a friction fit in the plastic breech.
Pull it forward, and out of the breech.
Transfer port shown in it's correct installation orientation.
These sometimes lift off the air tube when the breech is lifted.
Detail shot of the transfer port.
The "short" end with bevelled edge goes down into the rubber seal in the air tube, while the "long" end goes up through the breech into the barrel hole.
Installation is a reversal of the above.
If a steel breech is being installed, there is a retainer screw for the barrel in the top of the breech. I usually leave the barrel retainer screw well backed off until the barrel and air tube are properly aligned with the transfer port, and the two other screws are run up.
Excellent instructions, and two different sized allen keys come with the breech kit.
And a last, totally un-related photo
Grading marks on a choked Lothar Walther barrel.
Yes, they used gold foil.
It likes high end competition grade wad-cutter pellets, naturally.
Regards,
Doc Sharptail
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