Click on the pic and it will enlarge. Here, I've loosened the barrel band and removed the carbon fiber barrel extension. Follow the barrel back to the breech and you can see the discoloration and spot rusting.
Ordered a longer piece of 3K weave carbon fiber tubing (16mm OD/14mm ID) and waited patiently by the mailbox.
Rough cut it to length with a hacksaw. It'll run from the breech to the barrel band out by the muzzle threads.
Gingerly chucked it in the lathe and faced it to final length.
Razor sharp cutting tools are mandatory for working with carbon fiber, otherwise the material wants to splinter.
Some 400 grit paper put a good finish on the end.
Of course there was a snag--the carbon tube didn't quite fit over the barrel.
Chopped a piece of delrin rod and cut a slit in the end for some emery cloth
120 grit worked well. In about 20 minutes the tube was a snug fit over the barrel from muzzle to breech.
The barrel band will sit just aft of the muzzle thread. The short piece covering the muzzle will butt against the band. Should look like a continuous piece of carbon.
Backing up for a second. This is what the QB77 looked like before all this madness started. Pretty much a modern day version of the old Crosman 160/167.
This is where I'm at right now.
I've covered many of the modifications here on the blog. The extended bulk fill gas tube, the AR2078 stock, adjustable recoil pad and barrel band...
At some point, I made a screw cup, fit an accessory rail, and made a knurled hand stop and cuff sling.
Took some time, but the QB has gone from a rifle I couldn't connect with to one of my favorites. Not done yet. There's some valve work on the horizon to find a bit more velocity for the .25 pellets.
Thanks for checking in.
3 comments:
Nice post, I was going to follow your idea and purchase a .25 Trail XL barrel last week from crosman and they increased the price to I believe $37 dollars, so long are the days of the $18-20 barrel.
While I was reading the date of the initial post and seeing you were planning on posting an update last week I find it lucky that I just so happened to check back today and see an update post on this build.
Keep up the good work!
Looking forward to seeing where this ends up. Have been going through withdrawals, keep checking in with you guys every week or two. :-) What kind of velocity are you getting now with the rifle? What velocity are you hoping to reach?
I think $37 is still less than half of the cost of a .25 cal barrel from any other source. A .25 caliber conversion of a Crosman 22XX has been on my radar ever since reading about Dennis Quackenbush's version years ago. I've got another barrel but its not as simple as just turning the end down to fit.
The QB is limping along at something like 410 fps. Its slow, but its a big heavy pellet. I'd like to get it to around 500 fps+. Some valve work and a larger transfer port would probably do the trick. It'll happen eventually.
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