Airforce .457 Texan How low can you safely go ?

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swNCsw

swNCsw

Member
Sep 27, 2022
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665
Polk NC
I will start off by admitting I do not have any experience with the airforce line up . I picked up a .45 cal texan at the hickory NC airgun show around a year and a half ago .
I haven't messed with it much at all . I recently as of yesterday began putting a few rounds of cheap seneca 143 gr. round ball down range at 50 yards and was ok with the groups I was getting at 50 and in to 25 yards .

I would like to know how low I can safely tune it down too with out messing anything up before I try it lol.

Have any of you fellows tried to low power tune your texans ?

I am asking because I have a hunch or gut feeling that at some point I could experience a valve dump of some sort because of the design and strongly wish to avoid that situation from occurring . :LOL:

Thank you for any advice or input you are willing to share (y)
 
RM.510bigbore said:
Do not shoot a Texan Tx2 Valve low pressure under 2000 psi..It will break the valve....IT is pretty easy to use the power wheel and turn power down..The 45 Texan is pretty slow anyway 350 grain in 800-875fps...
Click to expand...
Thank you Sir for the sound advice . This is the older version and I do not believe it is a tx2 style valve . My bad for not getting that one in upfront .
 
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swNCsw said:
Does this mean I can safely turn it all the way down to near nothing in the older version valving with the 143 gn. round ball and it will not harm anything ?
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Usually you have to match how hard the hammer hits the valve with your psi...Sometimes light slugs need more max power on power wheel to open valve..IF you turn down power wheel too much valve wont open.. hope this helps a lil
 
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The TEXAN .457 is a very powerful model that can be adjusted to a lower power level. I have been experimenting with my 2018 model to shoot 145gn lead round balls that I make. To get no tank dumps or top hat damage as a few things must be done. The most important thing is to either reduce or remove the loading tray as I have done & gave the barrel chamber a little more lead to allow easier loading as it can actually not allow the slug/ball to enter the loading port unless it is also (reamed) down. I can adjust the hammer tension if required but the reduced valve opening is the secret.
To reduce the valve opening travel which is rather more than is required for the diameter of the air inlet channel. This is easy to try first with larger thickness Orings (eg 2mm) are inserted over the top hat to back of the nut as the original O-ring is too thin as it acts like a shock absorber when the( tophat/valve) slams shut. I have installed a 3mm brass ring along with a thicker O-ring & I can actually shoot down to 1000psi without any tank dumps. This modification was to test the velocity of the old (Lewis &Clark) 20 shot repeating rifle & still get around 600 to 700 fps from these low pressures.
People underestimate the lowly 145 lead round ball under 100m. I have taken many feral dogs with this system & of course the tank fill gives many extra shots. 200gn slugs still give more velocity over 500fps as that is all the Lewis & Clark rifle did as it only shot balls.
Yes, I have installed a regulator in the past, so the original bottle then becomes a plenum, but it only added to the weight with an extra .75ltr bottle. I no longer use it unless I need more pressure for heavier slugs.
 
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shortshell said:
The TEXAN .457 is a very powerful model that can be adjusted to a lower power level. I have been experimenting with my 2018 model to shoot 145gn lead round balls that I make. To get no tank dumps or top hat damage as a few things must be done. The most important thing is to either reduce or remove the loading tray as I have done & gave the barrel chamber a little more lead to allow easier loading as it can actually not allow the slug/ball to enter the loading port unless it is also (reamed) down. I can adjust the hammer tension if required but the reduced valve opening is the secret.
To reduce the valve opening travel which is rather more than is required for the diameter of the air inlet channel. This is easy to try first with larger thickness Orings (eg 2mm) are inserted over the top hat to back of the nut as the original O-ring is too thin as it acts like a shock absorber when the( tophat/valve) slams shut. I have installed a 3mm brass ring along with a thicker O-ring & I can actually shoot down to 1000psi without any tank dumps. This modification was to test the velocity of the old (Lewis &Clark) 20 shot repeating rifle & still get around 600 to 700 fps from these low pressures.
People underestimate the lowly 145 lead round ball under 100m. I have taken many feral dogs with this system & of course the tank fill gives many extra shots. 200gn slugs still give more velocity over 500fps as that is all the Lewis & Clark rifle did as it only shot balls.
Yes, I have installed a regulator in the past, so the original bottle then becomes a plenum, but it only added to the weight with an extra .75ltr bottle. I no longer use it unless I need more pressure for heavier slugs.
Click to expand...
Exactly what I was hoping for Thank you very much ! I will get started on the barrel work in the next few days . The 3mm ring should be easy enough to turn on the lathe lickity split woo hoo .

Thank you again shortshell for the important tip on the reduced valve opening being the key to avoid the tank dump ( in combo with the other mods) . (y)(y)(y)(y):giggle::cool:

I greatly appreciate You !!!! :coffee:
 
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Just some info I found out about the Texan .457 air flow. Years ago, I wanted to find out how much high pressure around 2500 psi would exit the long barrel after the slug has left the bore, so I made a 50mm x 400mm hollow pvc drain tube with a 15mm exit hole in the opposite end to the threaded crown to see how much air pressure is left after a 200gn slug exits tube This was not a suppressor just a test item. Well to my amazement & surprise the tube exploded & scatted bits of pvc all around my workshop as well.
That is an indication of the large amount of wasted air pressure still exiting the long barrel after the slug has left the barrel. This event made me investigate reducing the amount of exhaust air by reducing the valve opening dwell yet still get excepted velocity for round ball shooting & good penetration. I find any more than 1500psi is a waste for the small increase in velocity. Those old airgun makers of the early 1800's really knew what they were doing with only being able to get around 900psi before we started the power race we still search for. As a foot note I have shot balls with only 600psi & the penetration into soft wood shows these things are not toys. Long barrels are the secret to get slugs/balls up to speed.
 
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I am glad you weren't injured lol . You have saved me from some soiled shorts haha . If it is ok with you I will skip the pvc and take your word for it . ;):LOL:

I will start off my testing with the lower side of the pressure scale after the modifications and work my way up (y). You have helped me greatly . And save me from a few extra valve rebuilds .

Thank you again for sharing that information with us here at AGN kind Sir.
 
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shortshell said:
The TEXAN .457 is a very powerful model that can be adjusted to a lower power level. I have been experimenting with my 2018 model to shoot 145gn lead round balls that I make. To get no tank dumps or top hat damage as a few things must be done. The most important thing is to either reduce or remove the loading tray as I have done & gave the barrel chamber a little more lead to allow easier loading as it can actually not allow the slug/ball to enter the loading port unless it is also (reamed) down. I can adjust the hammer tension if required but the reduced valve opening is the secret.
To reduce the valve opening travel which is rather more than is required for the diameter of the air inlet channel. This is easy to try first with larger thickness Orings (eg 2mm) are inserted over the top hat to back of the nut as the original O-ring is too thin as it acts like a shock absorber when the( tophat/valve) slams shut. I have installed a 3mm brass ring along with a thicker O-ring & I can actually shoot down to 1000psi without any tank dumps. This modification was to test the velocity of the old (Lewis &Clark) 20 shot repeating rifle & still get around 600 to 700 fps from these low pressures.
People underestimate the lowly 145 lead round ball under 100m. I have taken many feral dogs with this system & of course the tank fill gives many extra shots. 200gn slugs still give more velocity over 500fps as that is all the Lewis & Clark rifle did as it only shot balls.
Yes, I have installed a regulator in the past, so the original bottle then becomes a plenum, but it only added to the weight with an extra .75ltr bottle. I no longer use it unless I need more pressure for heavier slugs.
Click to expand...
Good advice on reducing the top hats travel... Solid fix for anyone looking to reduce the power with out experiencing valve dump.
 
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swNCsw said:
I am glad you weren't injured lol . You have saved me from some soiled shorts haha . If it is ok with you I will skip the pvc and take your word for it . ;):LOL:

I will start off my testing with the lower side of the pressure scale after the modifications and work my way up (y). You have helped me greatly . And save me from a few extra valve rebuilds .

Thank you again for sharing that information with us here at AGN kind Sir.
Click to expand...
Be aware that if you go with ultra-light weight projectiles and low pressures... some combination will yield very high velocities. MY experience with 2,200 PSI and sabots under 50gr have gone supersonic.
 
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The Archer said:
Be aware that if you go with ultra-light weight projectiles and low pressures... some combination will yield very high velocities. MY experience with 2,200 PSI and sabots under 50gr have gone supersonic.
Click to expand...
Thank you very much kind Sir for sharing that knowledge !

I have recently found out the fun / hard way hahaha! . ;):ROFLMAO:

I am having a lot of fun with it !
 
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I have read your tune, it will help a lot of owners. I have found that around 1600psi will send a 145gn lead ball at around 950fps. Evan 220 gn. Cast Bullet Engineering ( an Australian company) solid slugs will get in the 800 fps with 1800psi. Even the h/p 330gn will get in the 700 fps area with that pressure. I have compared that power with a Colt 1911 45acp also shooting lead & they knock over steel pigs at 50m with ease. With the advent of thermal scopes feral dogs/cats do not stand a chance under 100m & property owners have no problems with stray shots traveling long distance as powder burners can do. The lower sound also does not wake up the neighbours. Suppressors are not allowed in our area.
 
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