In my limited experience with a few Beeman single shot and Crosman rotary-clip CO2 rifles too many shots in quick sequence chills the CO2 and reduces pressure. This causes shot string velocity to drop until CO2 and (and gun parts) temperature returns to near ambient. When I SLOWED DOWN my shot strings the velocity became much more consistent.This was REALLY noticeable on the rotary clip repeater when shots were fired in rapid succession. Another factor "I believe" that made the clip rifle WORSE was that a lot of extra CO2 got wasted/lost through/around the rotary clip making rapid fire velocities decline even faster.With a 90gram cartridge in the single shot rifle I got hundreds of consistent velocity pellets before shot string velocity started dropping rapidly. I believe that was the point when the liquid CO2 was gone and only CO2 gas remained. The result is very similar to when a regulated PCP rifle goes off-reg.
Quote from: mikeyb on October 24, 2024, 07:43:15 PMIn my limited experience with a few Beeman single shot and Crosman rotary-clip CO2 rifles too many shots in quick sequence chills the CO2 and reduces pressure. This causes shot string velocity to drop until CO2 and (and gun parts) temperature returns to near ambient. When I SLOWED DOWN my shot strings the velocity became much more consistent.This was REALLY noticeable on the rotary clip repeater when shots were fired in rapid succession. Another factor "I believe" that made the clip rifle WORSE was that a lot of extra CO2 got wasted/lost through/around the rotary clip making rapid fire velocities decline even faster.With a 90gram cartridge in the single shot rifle I got hundreds of consistent velocity pellets before shot string velocity started dropping rapidly. I believe that was the point when the liquid CO2 was gone and only CO2 gas remained. The result is very similar to when a regulated PCP rifle goes off-reg.I've had the same experience with other CO2 airguns with a rotary clip, such as the Crosman Vigilante, but none of those airguns, even using only 1 CO2 cartridge, would only give me 10-15 shots, no matter how fast I fired 10-pellets mags. I could get at least 35 shots, even firing as fast as I could pull the trigger. Methinks there's something else going on here...-W
Quote from: Whirligig on October 24, 2024, 08:07:45 PMQuote from: mikeyb on October 24, 2024, 07:43:15 PMIn my limited experience with a few Beeman single shot and Crosman rotary-clip CO2 rifles too many shots in quick sequence chills the CO2 and reduces pressure. This causes shot string velocity to drop until CO2 and (and gun parts) temperature returns to near ambient. When I SLOWED DOWN my shot strings the velocity became much more consistent.This was REALLY noticeable on the rotary clip repeater when shots were fired in rapid succession. Another factor "I believe" that made the clip rifle WORSE was that a lot of extra CO2 got wasted/lost through/around the rotary clip making rapid fire velocities decline even faster.With a 90gram cartridge in the single shot rifle I got hundreds of consistent velocity pellets before shot string velocity started dropping rapidly. I believe that was the point when the liquid CO2 was gone and only CO2 gas remained. The result is very similar to when a regulated PCP rifle goes off-reg.I've had the same experience with other CO2 airguns with a rotary clip, such as the Crosman Vigilante, but none of those airguns, even using only 1 CO2 cartridge, would only give me 10-15 shots, no matter how fast I fired 10-pellets mags. I could get at least 35 shots, even firing as fast as I could pull the trigger. Methinks there's something else going on here...-WI counted 30 pellets in 3 rapid-10 strings, at least 3 "dry-fires( = no mag or pellets left in mag), and 3 trigger pull shots. Yes, velocity start and fast drop were very unimpressive. IMO this is rotary mag inefficiency (leakage), rapid fire chilling, and a heavy hammer(more wasted CO2). There very well could also be CO2 leakage. An OBVIOUS HISS is a huge leak but there could still be a more subtle leak hurting the shot count performance.Tightening up the mag tolerances to reduce leakage may be possible but seems hardly worth the effort on a $60 plinking toy(IMO).Experimenting with the hammer spring may also be possible. On several of my PCP rifles the hammer adjust was WAY TOO HEAVY from the factory and dialing it back provided MANY MORE consistent shots per air refill.I expect ~60 good (fairly consistent for plinking) shots from 2x 12gram CO2 on my SINGLE shot rifles. My Crosman does about 3 mags, but is nowhere near as consistent as the BeemanUMAREX® CANEX RIFLE .177Manufacturer: Umarex AirgunsSKU: 2252122This item may be restricted from shipping to some areas $59.99Umarex Canex .177 Caliber CO2 Powered Multi-Shot Pellet Rifle Powered by (2) 12g CO2 Cartridges 700 FPS with 7 grain Lead Pellet 45 Shots with Fresh CO2 (3) 10-Shot 11mm Dovetail Scope Mount Fiber-Optic Front Sight Fully Adjustable Rear Sight Lightweight Polymer StockCompare?Crosman 1077 Co2 Air RifleRuger 10/22 Umarex Co2 ReplicaI agree the rifle seems like it should be performing a little better. At that price point factory construction is efficient (CHEAP) and QC likely non-existent. I'm not too surprised it is performing more like a toy than a real air rifle.There are GTA members who are experts at tuning/modding CO2 rifles (not I). Hopefully they will chime in with some better words of wisdom :-)
Quote from: mikeyb on October 25, 2024, 09:30:20 AMQuote from: Whirligig on October 24, 2024, 08:07:45 PMQuote from: mikeyb on October 24, 2024, 07:43:15 PMIn my limited experience with a few Beeman single shot and Crosman rotary-clip CO2 rifles too many shots in quick sequence chills the CO2 and reduces pressure. This causes shot string velocity to drop until CO2 and (and gun parts) temperature returns to near ambient. When I SLOWED DOWN my shot strings the velocity became much more consistent.This was REALLY noticeable on the rotary clip repeater when shots were fired in rapid succession. Another factor "I believe" that made the clip rifle WORSE was that a lot of extra CO2 got wasted/lost through/around the rotary clip making rapid fire velocities decline even faster.With a 90gram cartridge in the single shot rifle I got hundreds of consistent velocity pellets before shot string velocity started dropping rapidly. I believe that was the point when the liquid CO2 was gone and only CO2 gas remained. The result is very similar to when a regulated PCP rifle goes off-reg.I've had the same experience with other CO2 airguns with a rotary clip, such as the Crosman Vigilante, but none of those airguns, even using only 1 CO2 cartridge, would only give me 10-15 shots, no matter how fast I fired 10-pellets mags. I could get at least 35 shots, even firing as fast as I could pull the trigger. Methinks there's something else going on here...-WI counted 30 pellets in 3 rapid-10 strings, at least 3 "dry-fires( = no mag or pellets left in mag), and 3 trigger pull shots. Yes, velocity start and fast drop were very unimpressive. IMO this is rotary mag inefficiency (leakage), rapid fire chilling, and a heavy hammer(more wasted CO2). There very well could also be CO2 leakage. An OBVIOUS HISS is a huge leak but there could still be a more subtle leak hurting the shot count performance.Tightening up the mag tolerances to reduce leakage may be possible but seems hardly worth the effort on a $60 plinking toy(IMO).Experimenting with the hammer spring may also be possible. On several of my PCP rifles the hammer adjust was WAY TOO HEAVY from the factory and dialing it back provided MANY MORE consistent shots per air refill.I expect ~60 good (fairly consistent for plinking) shots from 2x 12gram CO2 on my SINGLE shot rifles. My Crosman does about 3 mags, but is nowhere near as consistent as the BeemanUMAREX® CANEX RIFLE .177Manufacturer: Umarex AirgunsSKU: 2252122This item may be restricted from shipping to some areas $59.99Umarex Canex .177 Caliber CO2 Powered Multi-Shot Pellet Rifle Powered by (2) 12g CO2 Cartridges 700 FPS with 7 grain Lead Pellet 45 Shots with Fresh CO2 (3) 10-Shot 11mm Dovetail Scope Mount Fiber-Optic Front Sight Fully Adjustable Rear Sight Lightweight Polymer StockI agree the rifle seems like it should be performing a little better. At that price point factory construction is efficient (CHEAP) and QC likely non-existent. I'm not too surprised it is performing more like a toy than a real air rifle.There are GTA members who are experts at tuning/modding CO2 rifles (not I). Hopefully they will chime in with some better words of wisdom :-)I think everything you wrote is spot on. I just traded in the Canex for another Canex and am re-testing velocities now. Shooting 7.9 grain CPHPs indoors at 74 degrees F, the first 10 shots were in the 550 FPS range, the second magazine gave about 500 down to 487 fps, and now I'm letting the CO2 cylinders warm up as I write this before testing the third magazine.Neither Canex had any audible hissing.So, this second Canex seems to be performing significantly better than the first one. I'll wait another 20 minutes for the CO2 to warm up a little, and see what numbers I can get with the third string of 10 pellets.-W
Quote from: Whirligig on October 24, 2024, 08:07:45 PMQuote from: mikeyb on October 24, 2024, 07:43:15 PMIn my limited experience with a few Beeman single shot and Crosman rotary-clip CO2 rifles too many shots in quick sequence chills the CO2 and reduces pressure. This causes shot string velocity to drop until CO2 and (and gun parts) temperature returns to near ambient. When I SLOWED DOWN my shot strings the velocity became much more consistent.This was REALLY noticeable on the rotary clip repeater when shots were fired in rapid succession. Another factor "I believe" that made the clip rifle WORSE was that a lot of extra CO2 got wasted/lost through/around the rotary clip making rapid fire velocities decline even faster.With a 90gram cartridge in the single shot rifle I got hundreds of consistent velocity pellets before shot string velocity started dropping rapidly. I believe that was the point when the liquid CO2 was gone and only CO2 gas remained. The result is very similar to when a regulated PCP rifle goes off-reg.I've had the same experience with other CO2 airguns with a rotary clip, such as the Crosman Vigilante, but none of those airguns, even using only 1 CO2 cartridge, would only give me 10-15 shots, no matter how fast I fired 10-pellets mags. I could get at least 35 shots, even firing as fast as I could pull the trigger. Methinks there's something else going on here...-WI counted 30 pellets in 3 rapid-10 strings, at least 3 "dry-fires( = no mag or pellets left in mag), and 3 trigger pull shots. Yes, velocity start and fast drop were very unimpressive. IMO this is rotary mag inefficiency (leakage), rapid fire chilling, and a heavy hammer(more wasted CO2). There very well could also be CO2 leakage. An OBVIOUS HISS is a huge leak but there could still be a more subtle leak hurting the shot count performance.Tightening up the mag tolerances to reduce leakage may be possible but seems hardly worth the effort on a $60 plinking toy(IMO).Experimenting with the hammer spring may also be possible. On several of my PCP rifles the hammer adjust was WAY TOO HEAVY from the factory and dialing it back provided MANY MORE consistent shots per air refill.I expect ~60 good (fairly consistent for plinking) shots from 2x 12gram CO2 on my SINGLE shot rifles. My Crosman does about 3 mags, but is nowhere near as consistent as the BeemanUMAREX® CANEX RIFLE .177Manufacturer: Umarex AirgunsSKU: 2252122This item may be restricted from shipping to some areas $59.99Umarex Canex .177 Caliber CO2 Powered Multi-Shot Pellet Rifle Powered by (2) 12g CO2 Cartridges 700 FPS with 7 grain Lead Pellet 45 Shots with Fresh CO2 (3) 10-Shot 11mm Dovetail Scope Mount Fiber-Optic Front Sight Fully Adjustable Rear Sight Lightweight Polymer StockI agree the rifle seems like it should be performing a little better. At that price point factory construction is efficient (CHEAP) and QC likely non-existent. I'm not too surprised it is performing more like a toy than a real air rifle.There are GTA members who are experts at tuning/modding CO2 rifles (not I). Hopefully they will chime in with some better words of wisdom :-)