by B.B. Pelletier
I’m on my way to Malvern, Arkansas, for the airgun show on Friday and Saturday. If you’re going to the show, please stop by and introduce yourself. I’ll have limited time to spend answering the blog comments, so I would appreciate it if the blog regulars would help answer questions from newcomers and new shooters. Now, on to today’s blog.
Today, we’re going to change the stock 12-inch barrel of our AirForce Talon SS for an optional 24-inch .22-caliber barrel. The caliber will remain the same but the barrel length will double. That will demonstrate the benefits of installing a longer barrel on a PCP.
Changing the barrel
AirForce barrels are held in the gun by two bushings around the barrel. These center the barrel inside the tubular aluminum frame. The SS frame is equal in size to the Condor frame. All that differs is the Condo scope base, which is longer. A 24-inch barrel fits the SS frame quite well.
Step 1: Make the gun safe
The first step is to ensure the gun is not cocked or loaded. The safety will be off for this procedure. Dial the power adjuster to zero to take tension off the barrel.
Step 2: Remove the end cap
The end cap is held in place by one 2mm Allen screw. Remove it, and the end cap comes out. It’s held tight by an o-ring to prevent vibration, so just pull a little harder than you think you should, and it’ll slip out.
Step 3: Remove the forearm
One 2.5mm Allen screw holds the forearm in place. Remove it, and the forearm comes off the gun.
Step 4: Remove the barrel
The barrel is held in place by either two or four 2mm barrel bushing Allen screws. The first guns, like mine, had just two screws, located in the channel under the forearm. Later guns had two more very short screws on the left side of the gun. They were just 1/8-inch long and beared directly against the side of each bushing. Today’s guns have two longer Allen screws in the same place, and they fit into holes in each bushing.
The barrel now comes straight out of the frame. If it is tight, just bump the muzzle end of the frame on thick carpet a couple times and the barrel will slide out. You only have to do this with the 12-inch barrel, as all other barrels come out to the end of the frame or past it.
The barrel is out, and you can install the new barrel. Since I’m installing a 24-inch barrel that will stick out of the frame by 6 inches, I can just slide it into position and fasten the screws. If I were installing the 12-inch barrel, I would need some kind of pusher because the 12-inch barrel sits down about 4.5 inches inside the frame.
The assembly is the reverse of the disassembly, but here are some tips.
1. Coat the thin section of the barrel with diver’s silicone grease or o-ring lubricant, because the bolt that slides on this section has two o-rings to seal it.
2. If you’re installing a 12-inch barrel, the alignment of the screw holes in the bushings is critical, because you won’t be able to turn the barrel when it’s inside the frame. So, check that before the barrel goes in.
3. Watch through one of the screw holes for the bushing hole to appear. Align it and install one screw. After that, all the other screws should be perfectly aligned.
4. When you install the forearm, don’t tighten the screw too much. It holds only by a couple threads; and if you tighten too much, you may cause firing problems.
The first time I swapped barrels, it probably took me 30 minutes, because I went very slow and was super-careful. The second time, it took seven minutes (I timed it) — and after that it took less than five minutes.
How does it work?
We have data from the 12-inch barrel, so now let’s shoot the gun on the same power setting with the 24-inch barrel.
With the 12-inch barrel, 14.3-grain Crosman Premiers came out at 854 f.p.s. They gave an average energy of 23.16 foot-pounds.
With the 24-inch barrel on the same setting, the same pellet averages 1027 f.p.s. f.p.s., for 33.5 foot-pounds of energy.
JSB Exact 15.9-grain domes
JSB Exact 15.9-grain domes averaged 823 f.p.s., producing 23.92 foot-pounds of energy.
With the 24-inch barrel, they average 991 f.p.s and make 34.68 foot-pounds.
Because the 24-inch barrel is so much more efficient, I can load the heaviest pellets and still shoot them with the SS powerplant. The 28.4-grain Eun Jin pellets that I would not shoot in the 12-inch barrel average 814 f.p.s. on the highest power setting and produce 41.79 foot pounds of energy. That’s not quite the 45 foot-pounds I’ve been reporting, but the Eun Jin I shot isn’t the heaviest .22 pellet, either.
The 24-inch barrel does improve the power with no other change to the gun. Next, we’ll see how it shoots.