On my impact with the factory TP hole I maxed my speed with .25 heavis at 860 to 870. This was 150 bar at the reg. By enlarging the TP hole I can reach the same speed with the reg set to 120 bar. Just curios why they wouldn't make the TP hole bigger from the factory. Is there a side effect of enlarging the TP that I'm not Aware of? Seems like a waste of air. I can reach 910 with the heavies maxed out now. I'm sure if I had a bigger hammer weight it might be more who knows.
Transfer port holes? Factory vs Aftermarket
- Thread starter Birdslayer25
- Start date
A properly sized transfer port could improve shot to shot consistency even on a regulated gun. It is shipped as a 45ft/lb gun, the factory transfer port is probably a better choice at that power level.
Upvote 0
I can set my gun to 105 bar and shoot the 25 grainers at 900 Fps and that's 45 foot pounds and you would get one hell of a lot of shots.
Upvote 0
If that bigger transfer port comes with similar efficiency, higher shot count, no change in extreme spread, and no change in standard deviation, then it is an uncompromising upgrade that FX should definitely change at the factory. I doubt that will be the case. Its all a balancing act. Lowering the operating pressure doesn't always increase shot count. Air rifles are more prone to hammer bounce at lower pressures. It's all a balancing act.
Upvote 0
G
Guest
Guest
Hi Birdslayer,
I am intrigued by your idea...I actually thought of trying it with my Wildcat. So please let me ask you some questions.
What did you use to enlarge your transfer port and exactly what size is the hole now? Is it still oval shaped or round?
You say you can reach the same speed as before with this lower reg pressure setting, but what happened with your extreme spread? Are you getting tight numbers or are you getting 20-30 ft/s difference between high and low shots?
Have you adjusted your valve spring to increase the dwell time the valve pin is open?
Isn't the air hole in the breech block the same size as the transfer port hole, or is it bigger?
Getting the velocity I want at the lowest possible reg pressure is my goal also, but I am limited to plenum size due to the location of the vent/breath hole in my air tube on my Wildcat.
All the best, Chuck
I am intrigued by your idea...I actually thought of trying it with my Wildcat. So please let me ask you some questions.
What did you use to enlarge your transfer port and exactly what size is the hole now? Is it still oval shaped or round?
You say you can reach the same speed as before with this lower reg pressure setting, but what happened with your extreme spread? Are you getting tight numbers or are you getting 20-30 ft/s difference between high and low shots?
Have you adjusted your valve spring to increase the dwell time the valve pin is open?
Isn't the air hole in the breech block the same size as the transfer port hole, or is it bigger?
Getting the velocity I want at the lowest possible reg pressure is my goal also, but I am limited to plenum size due to the location of the vent/breath hole in my air tube on my Wildcat.
All the best, Chuck
Upvote 0
G
Guest
Guest
I am also interested in knowing if you enlarged the transfer port in your impact pellet probe, and if so how did you accomplish this and what size was it before and what size is it now?
Upvote 0