Just received my new-to-me Vulcan 3 in .22 cal. with the 700mm CZ pipe. This is a gun that was new in Dec. so about 6 months old. Arrived in mint condition and seller is here on AGN with a big post count and travels for matches.
Gun came with a Regulator Tester Gauge as well as some convenient little extras. Since I am a tinkerer & always looking to improve my weapons’ smoothness and maximize accuracy I am definitely cranked to start this “project”. In this rifle the regulator is required to come Out of the Air Plenum Pipe and be put into the tester to get an accurate value, No “reg. pressure gauge” on side of rifle like many others today. The reg itself is a pretty large aluminum machined part and nothing like the little one in my Crown II.
In Previous life it was set to drive 34 gr. slugs at over 900 fps for long range target shooting. By owners account it was about 30 rnds. until time to refill. REG. was set at 130 Bar with Loads of Hammer-Spring pre load so not the nicest for Cocking smoothness. I brought hammer cap Out by 1/4” to flush with receiver and also greased the bore that the Rear of the pellet probe rides in during cocking stroke. It is a hidden path but made a very big improvement in the smoothness of the cocking cycle.
I don’t want to be pushing that heavy so I would like to Tune for 22-26 gr. Slugs and 25.4 JSB-RD’s at best accuracy I can achieve for 100 yd. Group shooting. Want to keep shot count a lot better than 30. The bottle alone is 580cc and the plenum is quite large too.
The Vulcan has an interesting design in that you can literally “Flip” the long Plenum Tube below the Action to Place Regulator in Forward end or Rear End of this Pipe in Relation to the “Popette Valve” at hammer. In doing you create Either a Huge Power-Plenum with Tons of Power capability OR a smaller sized plenum for more efficiency and higher shot count, but less horsepower.
** So far, after full disassembly (quite a busy disassembly if going all way down) and deep cleaning of barrel I set Regulator to 110 BAR and Changed its Location to the the Rear of the Plenum as described above so Not as much Power Capability.
Results at 1st Setting:
110 BAR, Small Plenum, Hammer Spring cap FLUSH with receiver and 25.4 MRD’s. = 661 fps
same, same, Harmer Spring Turned IN 1 Full Turn……. 25.4’s. = 845 fps.
Same, same, Hammer Spring Turned In 2 Full Turns ……. 25.4’s = 895 fps
Same, Same, Hammer Spring 3 Full Turns In …….. 25.4’s. = 910 fps
So Tomorrow I’ll Swap Reg to Large Plenum config and Keep at 110 Bar to See What Happens.???
After That I’ll be looking to Configure to be able to shoot 24 gr slug @ 1,050 fps. with the Hammer Spring Turned in 2-3 full turns SO I have the “Backing-Down Room” to get the ammo into Mid 800’s to 1,050 fps range just by adjusting the Hammer Spring tension easily in back of receiver.
Probably will need to Go Up a little on Reg Pressure but Don’t Know What the actual Velocity Effect will be when Kept at 110 Bar and just Swap Ends of Plenum. (good experiment)
Once things start to shake out in the Garage Tuning I will mount a new 8x34-56 Athelon on top and go Punch Paper. Can’t wait…
Gun came with a Regulator Tester Gauge as well as some convenient little extras. Since I am a tinkerer & always looking to improve my weapons’ smoothness and maximize accuracy I am definitely cranked to start this “project”. In this rifle the regulator is required to come Out of the Air Plenum Pipe and be put into the tester to get an accurate value, No “reg. pressure gauge” on side of rifle like many others today. The reg itself is a pretty large aluminum machined part and nothing like the little one in my Crown II.
In Previous life it was set to drive 34 gr. slugs at over 900 fps for long range target shooting. By owners account it was about 30 rnds. until time to refill. REG. was set at 130 Bar with Loads of Hammer-Spring pre load so not the nicest for Cocking smoothness. I brought hammer cap Out by 1/4” to flush with receiver and also greased the bore that the Rear of the pellet probe rides in during cocking stroke. It is a hidden path but made a very big improvement in the smoothness of the cocking cycle.
I don’t want to be pushing that heavy so I would like to Tune for 22-26 gr. Slugs and 25.4 JSB-RD’s at best accuracy I can achieve for 100 yd. Group shooting. Want to keep shot count a lot better than 30. The bottle alone is 580cc and the plenum is quite large too.
The Vulcan has an interesting design in that you can literally “Flip” the long Plenum Tube below the Action to Place Regulator in Forward end or Rear End of this Pipe in Relation to the “Popette Valve” at hammer. In doing you create Either a Huge Power-Plenum with Tons of Power capability OR a smaller sized plenum for more efficiency and higher shot count, but less horsepower.
** So far, after full disassembly (quite a busy disassembly if going all way down) and deep cleaning of barrel I set Regulator to 110 BAR and Changed its Location to the the Rear of the Plenum as described above so Not as much Power Capability.
Results at 1st Setting:
110 BAR, Small Plenum, Hammer Spring cap FLUSH with receiver and 25.4 MRD’s. = 661 fps
same, same, Harmer Spring Turned IN 1 Full Turn……. 25.4’s. = 845 fps.
Same, same, Hammer Spring Turned In 2 Full Turns ……. 25.4’s = 895 fps
Same, Same, Hammer Spring 3 Full Turns In …….. 25.4’s. = 910 fps
So Tomorrow I’ll Swap Reg to Large Plenum config and Keep at 110 Bar to See What Happens.???
After That I’ll be looking to Configure to be able to shoot 24 gr slug @ 1,050 fps. with the Hammer Spring Turned in 2-3 full turns SO I have the “Backing-Down Room” to get the ammo into Mid 800’s to 1,050 fps range just by adjusting the Hammer Spring tension easily in back of receiver.
Probably will need to Go Up a little on Reg Pressure but Don’t Know What the actual Velocity Effect will be when Kept at 110 Bar and just Swap Ends of Plenum. (good experiment)
Once things start to shake out in the Garage Tuning I will mount a new 8x34-56 Athelon on top and go Punch Paper. Can’t wait…