Airforce Question about a Donnyfl on my .457 Texan carbine FPS change

[crittahitta]

(Texan Carbine 3600 psi with the new TX2 valve) Ok so I was just upstate on my property sighting in my air rifles as I haven had much time to shoot as I am doing lots of work on my land. (Food plot and bedding area for deer) I will try not to make this too long. I bought a Donnyfl for my Texan carbine because it is super loud. It helped a lot. After using it I realized it was way too long with the Donnyfl on it to walk the woods so I had a muzzle break made for it and love it. Much shorter and easier to handle. Doesnt make it “quieter” but redirects the sound away from the shooter. So yesterday I got it all sighted in to 70 yards Using NSA 350 grain botail HP’s. Very happy. Then I decided to chronograph the slugs again.So last year the same slug was doing about 830 fps on the first shot With the Donnyfl on. Now with it off it was shooting very erratic. Sometimes 680 fps but mostly 770 fps. I don’t understand why this happened. Could the Donnyfl actually make the gun shoot faster? Even my other slugs were much slower (240 gr NSA HP) Then just to try the round balls at 3000 psi I found them going in the mid 600’s. I did not bring the Donnyfl with me this trip unfortunately to see if it helped or not. I will next trip for sure. Also the 240 gr NSA HP were going almost the same fps as the 350 gr. Then to make matters worse I adjusted he power wheel to make it faster and screwed up my point of impact. So next trip I have to sight it in again. Ugh!! Any help or Texan insight would truly be appreciated. Im so confused. Thanks.

 

[RM.510bigbore]

(Texan Carbine 3600 psi with the new TX2 valve) Ok so I was just upstate on my property sighting in my air rifles as I haven had much time to shoot as I am doing lots of work on my land. (Food plot and bedding area for deer) I will try not to make this too long. I bought a Donnyfl for my Texan carbine because it is super loud. It helped a lot. After using it I realized it was way too long with the Donnyfl on it to walk the woods so I had a muzzle break made for it and love it. Much shorter and easier to handle. Doesnt make it “quieter” but redirects the sound away from the shooter. So yesterday I got it all sighted in to 70 yards Using NSA 350 grain botail HP’s. Very happy. Then I decided to chronograph the slugs again.So last year the same slug was doing about 830 fps on the first shot With the Donnyfl on. Now with it off it was shooting very erratic. Sometimes 680 fps but mostly 770 fps. I don’t understand why this happened. Could the Donnyfl actually make the gun shoot faster? Even my other slugs were much slower (240 gr NSA HP) Then just to try the round balls at 3000 psi I found them going in the mid 600’s. I did not bring the Donnyfl with me this trip unfortunately to see if it helped or not. I will next trip for sure. Also the 240 gr NSA HP were going almost the same fps as the 350 gr. Then to make matters worse I adjusted he power wheel to make it faster and screwed up my point of impact. So next trip I have to sight it in again. Ugh!! Any help or Texan insight would truly be appreciated. Im so confused. Thanks.

Listen i have same problems..I only shoot my texan .510 CF tethered to my scba tanks at 3625 fps..My FPS spread is unacceptable...Its can shoot one hole at 50 yards..But 3 moa at 125 yards,,fps spread...I think its the nature of the beast... Maybe Some one has a special power wheel setting...I havent found it,, With 650 grain slugs tethered at 3625 psi i get fps spread from 740fps to 820 fps all slugs sized to .510.. Im pretty much over expecting more...Your problems not muzzle break or Donny FL making fps spreads..

 

[The Archer]

FYI: The moderator will not effect velocity, check the top hat and tune.

1. Top Hat, check the top hat to make sure the threads are not stripped and that it's adjusted properly. Typically you can turn the top hat out until it touches the feed ramp, then turn it back in 1 full turn. Fire the gun three times and check to see if the top hat moved. If it did the threads are likely damaged and needs replacing.

If your top hat tests good, you likely have the rifle tune set incorrectly.

2. Tune, a properly tuned Texan should give you very tight spreads of under 5fps when tethered, and about 15fps (3 shots) when not.


Copy this "How to tune your AirForce Texan for max velocity with the least amount of air" and past it into the search box at the top right of this page. It will take you to a post where I have instructions on how to tune your rifle, there is also a downloadable spreadsheet you can use to track your progress. Please let me know if this helps.


DG

 

[crittahitta]

FYI: The moderator will not effect velocity, check the top hat and tune.

1. Top Hat, check the top hat to make sure the threads are not stripped and that it's adjusted properly. Typically you can turn the top hat out until it touches the feed ramp, then turn it back in 1 full turn. Fire the gun three times and check to see if the top hat moved. If it did the threads are likely damaged and needs replacing.

If your top hat tests good, you likely have the rifle tune set incorrectly.

2. Tune, a properly tuned Texan should give you very tight spreads of under 5fps when tethered, and about 15fps (3 shots) when not.


Copy this "How to tune your AirForce Texan for max velocity with the least amount of air" and past it into the search box at the top right of this page. It will take you to a post where I have instructions on how to tune your rifle, there is also a downloadable spreadsheet you can use to track your progress. Please let me know if this helps.


DG

Thanks. Much appreciated