Author Topic: Converting .177 to .22 whats involved?  (Read 3106 times)

  • Guest
Converting .177 to .22 whats involved?
« on: May 14, 2007, 04:58:51 PM »
Its oblvious id need the barrel and bolt and orings. But hte question i have is I have a ar2078 tuned by mike and is there anyhting different between tuned versions of .177 and .22? Like larger valve holes and such between the calibers. Or would just a barrel and bolt be all that I need?

Offline IJL

  • Full Member
  • ***
  • Posts: 197
    • http://www.qbtune.zoomshare.com
RE: Converting .177 to .22 whats involved?
« Reply #1 on: May 14, 2007, 06:41:44 PM »
The only parts needed are the barell, bolt and O ring but I'm sure Mike would make other changes if he had it on his bench, like matching the ports and maybe different sizes too although out of the box the valves are identical.

Ian

  • Guest
Re: Converting .177 to .22 whats involved?
« Reply #2 on: May 14, 2007, 06:47:32 PM »
Yeah thats what I was wondering about the ports not matching. Would it make that big of a differance if they wernt?

Offline Gene_SC

  • Hero Member
  • *****
  • Posts: 11378
    • http://www.airguntoys.com
Re: Converting .177 to .22 whats involved?
« Reply #3 on: May 14, 2007, 10:43:46 PM »
Probably would..:) Mike can fix you up with that.. Just send him an email with the question and he will get back to you..

Gene
THE ONES I SLEEP WITH: BSA Lightning XL, AA TX-200, AA ProSport, BSA Ultra, HW-97K, Crosman NPSS .177, FX Cyclone, HW-30 Nicle Plated, AA-S200, Crosman Marauder, CZ-634, R-9 DG, Webley/Scott UK Tomahawk, Benji Kantana, Benji Marauder, Benji Discovery.....
....

Gene\'s Tunz n Toyz
Springer Tunin

Offline mikeiniowa

  • Hero Member
  • *****
  • Posts: 1110
    • http://airgunartisans.com/flyingdragon
RE: Converting .177 to .22 whats involved?
« Reply #4 on: May 15, 2007, 04:11:12 AM »
The way I set up most of the .177's is with a slightly restricted entrance to the valve body compared to the way the .22 is set up, the smaller bore doesn't need as much flow to get the pellet going. For the life of me I can't remember how yours was set up, next time the charge is done look into the gas tube and see what the end of the valve body looks like, if it has an opening all the way across the end of the valve it will convert to .22 with no velocity problems, if it doesn't have the cut out you will have slightly lower velocities in .22 as the gas flow will be somewhat restricted.   The port in the .22 barrel will need to be  drilled out to .170, you can use the same seals etc. other than on the probe. May want to do the wire extention for the best velocity.

  • Guest
Re: Converting .177 to .22 whats involved?
« Reply #5 on: May 15, 2007, 04:55:45 AM »
Ok mike there si a slit to remove the valve, and there is also another slit (to make an X shape) in the valve that is ground out. I dont know how else to explain it.

Offline mikeiniowa

  • Hero Member
  • *****
  • Posts: 1110
    • http://airgunartisans.com/flyingdragon
Re: Converting .177 to .22 whats involved?
« Reply #6 on: May 17, 2007, 01:43:30 PM »
OK you have the full power valve installed, you will need a .22 barrel and a .22 bolt, with the barrel and receiver removed from the rifle, slide the barrel itno the receiver and install the set screw that holds it in place, drill out the port in the bottom of the barrel to .170 inches, try to get the port right in the middle of the hole in the bottom of the receiver, most of the time thay line up perfectly, remove the set screw and pull the barrel out of the receiver and deburr the port on the inside of the barrel, I use a 5/32 inch sharpening stone for a chain saw to remove the big stuff and then wrap 220 emery paper around a drill bit to begin smothing the area, work your way up to 600 grit to get it real smooth, the same method can be used to smooth the loading tray for the pellet, be careful not to bugger up the area where the o-ring for the probe seats, it's the raised area just inside. For the bolt you can center drill for a probe,  use a 1/16 inch bit, the bit will self center when you do this, drill in about 1/8 to 3/16 inch, no need to get to deep here, cut the probe off just behind the port, check by assembling the barrel, receiver and bolt and make sure the cut off probe doesn't block the port you drilled in the bottom of the barrel, if it's clear of the port then you can insert the drill bit and measure from the shoulder of the bolt out 1 3/8 inch, mark the drill bit at that length and cut it off, a drop of super glue will hold it in place. I you don't want to try the extended probe, use some wire size drill bits and drill out the end of the factory probe taking about 5 or 6 thou. at a shot, it will take a few changes of bits until you get to around .170 inches, then drill out the port in the bottom of the probe, don't drill the port out first, you may twist the end of the probe off if you do, If you should need seals or o-rings let me know and I'll send a set or two to you, good luck, if you should have problems let me know, I'll do what I can to help. Mike

  • Guest
Re: Converting .177 to .22 whats involved?
« Reply #7 on: May 17, 2007, 01:59:04 PM »
Wow mike thanks alot for the information. That is a big help explaning it all like that. And now knowing that that is all that is needed to be done. You will be getting an email from me shortly.


Thanks again :)