My1322 with Quick-Change Barrels

[Don Clark]

About a year ago I asked fellow airgunner and good friend Jim Bentley a big favor.  Would he make my steel-breeched 1322 a switch-barrel so I could turn it into a carbine or back into a pistol without having to pull the breech off the pump tube?  With his background in engineering and metalwork, I knew he could do it if he wanted to.  Anyone else might have told me to "buy a Drifter to go with your 1322 and just switch the gun in your hand when you need a longer barrel."
 
Instead, Jim agreed to look at a YT video made by a British airgunner who had modified a 2240 to take either the stock 7.5 inch barrel or an 18 incher with no more disassembly than loosening a pair of barrel setscrews in his aftermarket breech.  He necked the ends of the barrels and threaded them into a short sleeve inserted in the breech.  He secured the sleeve with a third setscrew through the top of the breech, close to the loading notch, and with a transfer port he made that threaded into the gas chamber.  Gaskets slipped over the barrel threads sealed the necks where they contacted the front edge of the breech sleeve.
   
After watching the video and thinking on the project, Jim supposed he could simplify the modification by relying mostly on Crosman's transfer port for sealing rather than on threads, gaskets, or O-rings.  He'd discourage downstream leaks by necking my 10.25 and 18 inch barrels for a snug fit in the breech sleeve, and by adjusting the length of their necks so they'd butt tight against the breech's rear wall when the barrel ports were centered over the sleeve, breech, and compression tube ports.  The sleeve would be held in the breech only by the transfer port tip extending into its wall and indirectly by a single breech-top setscrew dimpled into the barrel ahead of it.  Seating the screw in the dimple would assure that the barrel had been rotated to align its port with the other ports.
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To make an aftermarket band for long barrels accept the short one, Jim made an extension for it that adds ½-20 moderator threads on the front end.  The 1322 barrel comes with a neck at the muzzle to fit Crosman's band.  Jim lengthened and knurled that neck to give the extension's sleeve a good grip on the barrel for an interference fit.
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It took Jim a while to find time for the job, but once started he finished it quickly. Subsequent leak testing proved that his simplified sealing worked.  A scrap of single ply tissue hung over the breech where a barrel enters it doesn't jump when a 14.3 grain pellet is fired at 10 pumps.  And with the small air volume and relatively low pressure involved, there's no danger of the barrel and tube being launched with the pellet.  I doubt there'd be any risk even with higher pump counts.

Here's the complete ensemble.  Most of the accessories are from Buck-Rail.  Both barrels use the B-R moderator.  The stock is the B-R folder, with a knob-head screw Jim made to replace the issue socket-head for quicker mounting and removal.  A Pachmayr sleeve on the pistol grip makes it more comfortable.  The dogleg in the pump handle I built increases leverage and silences handle slap with a stub of plastic tubing sunk in the pump tube channel Sheridan style.  Internal modifications were made previously to improve the trigger and increase pumping efficiency.  Finally, with either the stock or the long barrel dismounted, the entire rig fits in a 13 x 26 inch Doskocil case. 
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My 1322 may have become unique, thanks to Jim.  All he'd accept in return for his labor was the promise of a free beer occasionally.  Now there's a true friend!

[MoWog72]

I had to read through your post a few times to wrap my head around the machine work involved considering that Crosman barrels are harden steel (I believe).Quite impressive! Buck Rail makes some nice products. I recently received his 1/2-20 moderator like yours which mates up nicely with a threaded  aluminum barrel band which I purchased on ebay from Han Chen in Germany.