AirForce Texan: Part 3
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- TX2 valve for .45 and .50 caliber Texans
- Old rifle, fresh test
- “New” bullets
- The TX2 valve
- Power setting
- Seat the bullet in the rifling!
- One more velocity lesson
After writing Part 2 of this report last week I went to AirForce last Friday morning and spent a couple hours with Ton Jones, talking about the Texan and the new TX2 valve and carbon fiber tank. I took my Texan that was made in the first production run, and we attached the new tank to it. That answers the first question — does the new tank fit older Texans?
The TX2 valve boosts power and currently only the .45 and .50 caliber Texans work with it. There is also a difference between the valve cap on the .45 and the .50 caliber valve, so to use the same tank on both airguns the cap needs to be exchanged.
Old rifle, fresh test
Reader Chris USA mentioned that my last report on the Texan was in August of 2015. Yes, it was. The accuracy and velocity data I have given you thus far came from those reports. Since there is a new tank and valve, I conducted new velocity testing with my same rifle and a new tank last Friday. I will cover that later in this report.
Chris also suggested that I try some of the “new” lead bullets that are being made for the Texan. I hope to do a little of that, but since conical lead bullets are 160 years old, there isn’t really anything I haven’t seen. I think what Chris is really asking for are my comments about some of the bullet makers who are in the market. What I see is a lot of guys who don’t know lead bullets are responding to things the sellers are telling them.
Well, one thing I learned last Friday was the newer Texans come with a barrel that has a twist rate of one turn in 30 inches. They have done this to accommodate the heavier bullets people seem to use. I don’t know what the twist rate is in my barrel and AirForce asked if I wanted to change over, but my rifle is so accurate now that I want to leave it as it is.
The TX2 valve
The TX2 valve is unique in that is has no spring to push it closed. It relies on air pressure alone to do that.
In Part 2 I showed the power setting I used for my tests in 2015. Well AirForce has changed the power setting mechanism and Ton told me my rifle was set wrong for the TX2 valve. The index mark needs to be between the first and second notch on the right for heavier bullets and never past the second mark for anything. Since heavier bullets remain in the barrel longer than light ones, They maintain back pressure against the firing valve — holding it open longer.
So we set it as high as it would go. That means the most spring tension on the striker. On newer guns you may lose sight of the index mark when you reach the end of the adjustment range.
The power adjustment wheel is turned as far to the right as it will go — putting maximum tension on the striker spring. This was set for the lightest bullets we tested.
These are the power settings on the Texan power adjustment wheel. According to Ton Jones you should never go lower than the second mark that’s shown as 3/4 power in this picture when using the TX2 valve. You want to make that setting your lowest point for the standard tank, as well.
Seat the bullet in the rifling!
If there was one big mistake I made in part 2 it was showing you a bullet laying in the loading trough and telling you that the bolt would push it home. Well, it doesn’t work that way. I’ve gone back and corrected the language in Part 2 and now I have to tell you how important it is to manually seat each bullet into the rifling. I knew that from testing the TexanSS in 2018, but for some reason I reported it wrong in Part 2 of this report. And some bullets present problems, as well. For example, the semi-wadcutters that were the most accurate in my Texan want to enter the breech tipped on an angle unless they are pushed into the rifling. Their angled nose is the reason for this. Once the front band of the bullet encounters the rifling, it squares up the bullet with the bore and everything is okay. You also get more consistent velocity that way.
Ton took me outside and let me listen to a shot with a well-seated semi-wadcutter. It bellowed , which is how you know it’s seated right. And I heard the bellow through my electronic noise-suppression headphones.
Okay, I said that the TX2 valve gives fewer shots than the standard valve. Let’s see. We’ll check the velocity with a 490-grain flat nose bullet made by Mr. Hollowpoint — Robert Vogel. There you go, Chris!
The tank was filled to 3600 psi and the gun was fired. The bullet went out at 776 f.p.s. That’s 655 foot-pounds at the muzzle. We topped it off a second time and the next bullet went out at 778 f.p.s. for 658.74 foot-pounds. This time we did not refill the tank.
The tank registered 2590 psi after three shots. We then went outside and Ton fired shots 4, 5,6, and 7. On shot 7 there was a partial tank dump and on shot 8, with just 800 psi showing on the gauge before the shot, the tank dumped all its air. I would say shots 4 through 7 were good enough for finishing shots on game that was down.
One more velocity lesson
Ton filled the tank to 3,600 psi and loaded and shot a 210-grain bullet. It went out at 620 f.p.s. That left 3300 psi in the tank. He told me to watch what happened to the velocity as he shot more.
3………..726 3130 psi remains
4………..795 3050 psi remains
Velocity is increasing as tank pressure drops since there is no valve return spring to close the valve. Want a lot of shots from a big bore? Here they are! And, if you want to increase the velocity — reduce the pressure in the tank!
We’re just getting started with the Texan. It’s a big bore with performance you can stretch! I have a lot more to tell so don’t go away.