Airforce Tuning .457 Texan SS

[USMCShooter1]

So I’ve had two shooting sessions with the new Texan SS. I’ve shot NSA 220’s and 240’s, the 240’s shoot the best to 100 yards.
I got some 279gr Hunters Specialties with a big meplat, which is what I prefer…they’re 3 inch at best at 50, and 6 inches at 100.
Mr.hollowpoint 250’s shoot similar. But the 280’s shoot on top of each other at 50, and about 3 inches at 100…with how well both the NSA 240’s and Mr. Hollowpoi’s 289’s shoot at 50, my thoughts are they’d shoot a lot better at 100.
Now, I’m an extremely experienced shooter. USMC Shooting team, bench rest competitor among multiple genre’s. I’m confident it’s not me.
I need to tune it more, but I’m tuning to Air Force’s recommendations of running the adjuster all the way towards the breach for the lighter bullets…but I’ve shot it enough across the chrony to get max velocity at about 50% on the wheel. I’ve not gone much further than that.
It seems to me there would be an adjustment where I’d get on shot at (example only) 880fps, 2nd shot at 905 FPS, and third at 860fps. All of my adjusting so far results in constant drop from first shot.
I’m going to play with it more, but for you AF big bore gurus, I’m all ears.

V/R
Gunner

 

[RM.510bigbore]

Tuning is easy for Texans...You need a external regulator... Off of your scba tank...

 

[Ezana4CE]

Which diameter slugs are you shooting that are producing the stated results? Have you bore scoped your barrel? Have you slugged your barrel?

 

[pnwairgunner]

Try Nielsen 290s. They pretty much clover leaf at 50 yds if I’m shooting tethered. Un-tethered it gets two perfectly usable shots in the deer kill zone with the same aim point.
I use my Texan for deer hunting mainly so I really only shoot one shot with it when I go hunting. I don’t need a long regulated shot string for what I mainly use it for.
I would say though, my own lengthy experience with powder burners was not a sure ticket to peak performance when getting into airguns. It’s a whole different animal. I can’t say that proficiency in one discipline is going to necessarily translate into success with the other. Imagine the lock time difference between a .50 muzzle loader and a .338 lapua. Now reduce the muzzle loader power level down to what we are getting with a big bore airgun. Huge difference. Follow through is more important than ever with an airgun and they generally don’t like to be held super tightly. The list goes on.
Just my 2 cents worth, which in this economy won’t buy you much.

 

[USMCShooter1]

Thanks PNW Airgunner,
I’ve been in the “adult” airgunning world for over 15 years now, and have primarily hunted with them since, so extremely familiar with their intricacies. I was heavily involved until I retired from the ‘Corps 10 years ago, and on multiple forums doing product testing for nearly every manufacturer in the game back then.
I dipped my toe in the big bore game with a 70-45, which shot surprisingly well with lighter bullets but didn’t have the grunt I was seeking.
Moved into a Piledriver which shot extremely well with multiple slugs and would stack 3 NSA 240’s or 290’s on top of each other at 100 yards. But just too danged long and unwieldy…like trying to carry a fishing rod through the woods or into a ground blind, lol!
The Texan SS/CF fits the weight/length bill, and shoots great with several slugs to 50 yards, but seems to fall apart at 100…I’ve shot NSA 220’s, 240’s and 290’s, HS 279’s, Mr. Hollowpoint 250’s & 280’s…it’ll drop one in the center and the next one 5 inches left or right and a little low, and the 3rd the other direction at similar elevation…velocities average 868,812,786…with 280-290 slugs…it seems like a 1.5 inch group at 50 wouldn’t translate to 5 inch groups at 100…I shot my buddy’s LSS Sunday and it’s printing 3 shots into 2 inches with several of the same slugs…

 

[Llama]

I was just wondering if you guys got any further on what was going on with this setup