AEA AEA Challenger barrel cut/re crown

[cilami]

Hi all,

I have a Challenger Bullpup .25 that needs a new barrel end. So I would like to cut 1/2" inch or so, and then re crown. The barrel is not choked. I'll need to extend the threads, for the bushing. My question is...can this job be a diy thing or would be wiser to send the barrel to someone with expertise?. Any names to recommend? I am not bad with hand tools, but I don't have a lathe. Advice and comments will be appreciated.

 

[AirNGasman]

I did exactly what you're contemplating to my .22 Challenger myself, in order to remove a badly done crown polishing by the previous owner that penetrated about 1/4" into the rifling (off-center). The bushing you mention being about 3/4" long, I cut 3/8" off the barrel (muzzle); leaving about 3/8" of threaded muzzle to still engage with the bushing. That worked, but unfortunately accuracy is still disappointing.

.

 

[nervoustrig]

Turning down the OD in preparation for threading is likely the biggest challenge. If you have a sufficient level of DIY spirit, you can improvise a crude lathe with a drill or drill press to spin it up and support the muzzle with a bushing. The bushing can be a piece of wood with a hole drilled in it. Spin it up and then kiss the surface with an emery wheel to abrade it down to the desired diameter.

Next up is holding the barrel well enough to use a threading die without squeezing it so hard as to deform the bore. How tricky that is will depend largely on how thick the wall is. Contrasted with single-point threading on a lathe where the forces are considerably less.

 

[cilami]

I did exactly what you're contemplating to my .22 Challenger myself, in order to remove a badly done crown polishing by the previous owner that penetrated about 1/4" into the rifling (off-center). The bushing you mention being about 3/4" long, I cut 3/8" off the barrel (muzzle); leaving about 3/8" of threaded muzzle to still engage with the bushing. That worked, but unfortunately accuracy is still disappointing.

View attachment 570160

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Interesting. After cutting 3/8", how the rifling looked like? Maybe you needed to remove a longer piece of muzzle? I also think that is important to check the other end of the barrel for sharp edges or burs. By the way, what kind of accuracy are you getting after the cut/recrown? Now I am getting an average of 3/4" ctc groups at 35 yards. Maybe I am asking too much from the bullpup...

Show quoted text

 

[cilami]

Turning down the OD in preparation for threading is likely the biggest challenge. If you have a sufficient level of DIY spirit, you can improvise a crude lathe with a drill or drill press to spin it up and support the muzzle with a bushing. The bushing can be a piece of wood with a hole drilled in it. Spin it up and then kiss the surface with an emery wheel to abrade it down to the desired diameter.

Next up is holding the barrel well enough to use a threading die without squeezing it so hard as to deform the bore. How tricky that is will depend largely on how thick the wall is. Contrasted with single-point threading on a lathe where the forces are considerably less.

Thanks for the ideas. I have and old Marauder pistol barrel not in use, and think I will use it to practice if I decide to give this a go.

 

[AirNGasman]

Interesting. After cutting 3/8", how the rifling looked like? Maybe you needed to remove a longer piece of muzzle? I also think that is important to check the other end of the barrel for sharp edges or burs. By the way, what kind of accuracy are you getting after the cut/recrown? Now I am getting an average of 3/4" ctc groups at 35 yards. Maybe I am asking too much from the bullpup...

Show quoted text

Having very successfully cut and re-crowned about a half-dozen airgun barrels that came out at least as accurate (or more-so) than before chopping, of course the cut barrel Challenger barrel looked like the hack-sawed mess it was before I ground it square on a sander, polished the end of the muzzle, and re-crowned it. Now it looks professional, like all my previous barrel chops.

After posting my reply above I got the Challenger out to revisit, after several months of neglect due to higher priorities. Removed the shroud and baffles, inserted a spring between 2 baffles, re-assembled, charged and shot several groups at 50 yards in gusty crosswinds with 18.1 grain FX pellets at 1053 FPS/44.6 FPE that I've tuned the rifle for. Apparently the spring/baffle trick worked, as she was getting consistent 1" five-shot groups in those gusty winds.

BTW, I've also fabricated a sear-engagement adjuster, to get the trigger down to a crisp, 2 pound break.

 

[cilami]

Having very successfully cut and re-crowned about a half-dozen airgun barrels that came out at least as accurate (or more-so) than before chopping, of course the cut barrel Challenger barrel looked like the hack-sawed mess it was before I ground it square on a sander, polished the end of the muzzle, and re-crowned it. Now it looks professional, like all my previous barrel chops.

After posting my reply above I got the Challenger out to revisit, after several months of neglect due to higher priorities. Removed the shroud and baffles, inserted a spring between 2 baffles, re-assembled, charged and shot several groups at 50 yards in gusty crosswinds with 18.1 grain FX pellets at 1053 FPS/44.6 FPE that I've tuned the rifle for. Apparently the spring/baffle trick worked, as she was getting consistent 1" five-shot groups in those gusty winds.

BTW, I've also fabricated a sear-engagement adjuster, to get the trigger down to a crisp, 2 pound break.


View attachment 570248

That sear-engagement is really ingenious! And the spring trick too. One inch at 50 yds. in gusty winds seems good to me. You probably fixed the barrel and did'nt realize it until today jk. Should try in good conditions.

In my bullpup, I removed the baffles and installed a Ronin. Accuracy improved after that. Polished barrel. I ordered a barrel band and I plan to do some trigger work and set it to about two pounds also. This afternoon I tried NSA 36.2 grain slugs and FX 25.4 pellets and got 1/2" ctc groups at 35 yards, with moderate wind. AA Diablos 25.4 did'nt group. Neither JSB's 33.95. There are simply too many pellets/slugs to try...I think I am not going that route for now. My ultimate goal is to achieve moa groups at 50 yds., consistently. The cut/re crown project would be my last attempt at it. Do you have pics of your cut/re crown methods and tools?