Air force texan accuracy-need help

I love my SS. Very accurate I have taken a few big hogs at over a hundred yards.
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Very Nice.
 
Complaints about poor accuracy for .308 Texans abound, yet other Texans in different calibers can be very accurate out of the box.

I know several shooters that have three or four Texans and all have told me of problematic .308's.

Nick at NSA himself has commented on having problems with developing a good bullet with his .308 and that it took much more work than any of his others.

Note my .457 Texan can and has frequently shot 1.25" 3 shot groups both tethered and off tether at 100 yards, and I'm a 63 year old 'shakey' guy, haha.. And the .357 is similarly accurate. Multiple .257 shooters have gotten 1/2" at 100 so it's not the gun itself.

No one I've communicated with has told me a 'solution' and Air Force denys there is a problem. Interestingly enough, I know two people who had their .308's re-barreled AS .308's and the change made them laser accurate compared to the factory barrel. So it's not the gun itself but 'something' in the barrels they used.

Personally, I'm going to go to a 7mm barrel and dropping 308 for the better SD and BC






 
Complaints about poor accuracy for .308 Texans abound, yet other Texans in different calibers can be very accurate out of the box.

I know several shooters that have three or four Texans and all have told me of problematic .308's.

Nick at NSA himself has commented on having problems with developing a good bullet with his .308 and that it took much more work than any of his others.

Note my .457 Texan can and has frequently shot 1.25" 3 shot groups both tethered and off tether at 100 yards, and I'm a 63 year old 'shakey' guy, haha.. And the .357 is similarly accurate. Multiple .257 shooters have gotten 1/2" at 100 so it's not the gun itself.

No one I've communicated with has told me a 'solution' and Air Force denys there is a problem. Interestingly enough, I know two people who had their .308's re-barreled AS .308's and the change made them laser accurate compared to the factory barrel. So it's not the gun itself but 'something' in the barrels they used.

Personally, I'm going to go to a 7mm barrel and dropping 308 for the better SD and BC


You are correct, the complaints on the 308 have been out for awhile now and I’m surprised AF hasn’t done anything to correct it.
 
Yes I can add something, not specifically for the .308 but something that probably applies to all Airforce guns. 

I had the priviledge of hosting Brian this past weekend for some whitetail and turkey hunting on my farm in north Florida. Between hunts we did a lot of shooting. My .308 started acting up and spraying everything we put in it. I polished the barrel and tried every other small fix I could think of and we were still getting odd fliers between groups of 2 or 4 semi tight patterns. 

Brian suggested we tether the gun. When we did so at or around 3200psi, it became a laser with everything we put in it at 50 yards. When we untethered it, it started spraying again, even though velocities didn’t significantly change. We speculated that perhaps the changing of the pressure during the shot string was causing violent vibration in the gun. I then checked the spin loc tank and saw that it was hand loose. All weekend it had been coming loose and I had been hand tightening it whenever it came loose. 

We took the Airforce wrench that’s made for the spin loc tank and tightened down as tight as possible. Then the gun became a tack driver again and has been so ever since. 

I’ve thought back to when my Condor was fickle, and often I’d keep the spin loc tank hand tight and not tool tight. Its a very accurate gun now, and conicidently (or not) the tank is also very tight. 

I tool tightened my .45 SS and its also now consistently drilling with Nielsen 290s at 50 yards.

Finally, my brother sent me his Condor to diagnose his own accuracy issues with it. The tank was loose to the touch. I’ve got it tightened down good now. I’m going to polish the barrel then shoot groups with it. I bet the tight tank will solve the problem.

Again, this is a fix more for all Airforce guns and not the .308 specifically. I think a loose tank is contributing to frame flex and may be the reason Airforce guns can seem like they shoot awesome one day and poorly the next

As far as .308s, my .308 likes the following:

45 gn JSB pellets, 45 gn Polymags, 50 gn JSBs, 59 grain NOE cast pellets, and 99 gn Nielsons. Out to 50 yards anyhow. I’m not interested in deer hunting beyond that range. 

If your gun’s barrel just doesn’t like the above, I don’t have an answer for you. But do suspect frame flexing relative to tank tightness if your gun seems to be fickle with anything you put in it. 
 
ON an Airforce gun a loose tank means inconsistent contact between Valve and hammer / breech / bolt which leads to inconsistent velocities as well. 

If the valve is canted one way or another nothing will be consistent. That is why the spin lock system has a wrench AND a locking set screw for the collar.

In case you can't tell I have made this mistake also in the past. I now have 8 Airforce guns and all shoot consistently and accurately.
 
Here's the 5 shot group from the 99 gn Nielsen's on the video at 30 yards:

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Shots 1-3 are on the money, and shots 4 and 5 are dropping. Shots 1-3 are around 180fpe. 

Tonight I was deer hunting and a coon strolled out that I took a pot shot at. At 45 yards I overshot his back fairly severely. I wasn't sure if that was me or the gun (I took a bad fall yesterday that bruised my ribs and I had the gun slung on my back when that happened). So I checked the zero at 50 yards tonight...

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The 2 shots in the bullseye are actually shots 2-3 on the fill, because shot 1 went to the coon. Shot 4 started to drop. That's a consistent pattern with what I filmed on the video. At 180fpe, this is basically a 3 shot gun, with the next 2 shots after that being usable but dropping. 

I think its clear the gun really likes the Nielsen 99 grainers. 

I've also experimented some with pellet tunes for the deer stand, meaning a tune for the gun that would let me drop a pellet in and take a squirrel with minimal noise and air usage on a full tank while keeping my tank within that first 3 shot PSI range. Seems like spinning the power wheel down a few spins will get me shooting the 50 grain JSBs in the 880s at or near 3000psi with roughly the same POI as the Nielsens at full power. Its basically valve locking the gun just a bit but its very quiet and just sipping a little bit of air. I'm going to experiment with it more to see how many shots I can get with the pellets at that power level without moving too far away from 3000psi.

Otherwise, to set the gun up just as a pellet shooter, you'd want to fill it to just above 2000psi and turn the power wheel all the way down. You'll get about 15 shots when your curve starts to level out around the 90fpe range. 
 
@Bullfrog, you’re definitely on to something with the versatility of the .308 Texan. It not surprisingly likes the Nielsen 99’s, but I was shocked at how well it shoots .30 pellets at 50 yards. The thing that’s the most intriguing is you’re moving back and forth from different projectiles at very different power levels and your point of aim is basically the same.

Looking forward to seeing it put to use on FL deer AND small game!

Brian 


 
I think velocity more so that power is the deciding factor for POI, at least out to 50 yards. When the Nielsens and JSBs are each flying at 900fps, POI appears to be the same between the two. Eventually the POI of the JSBs should shift before the Nielsens do at a particular range because the Nielsens are carrying more energy with a better BC. But for hunting purposes at 50 yards I can’t see a difference between the two so long as their exit velocities are comparible.