Hunting with big bore airguns: What to expect

by Tom Gaylord
Writing as B.B. Pelletier

This was originally published as “AirForce Texan big bore rifle: Part 4” because I was writing about that big bore rifle at the time. It doesn’t really apply only to that model, so the title was changed.

AirForce Texan big bore rifle: Part 1
AirForce Texan big bore rifle: Part 2
AirForce Texan big bore rifle: Part 3

Texan big bore
The Texan from AirForce Airguns is a .458 big bore to be reckoned with. The scope and bipod are options.

This report:

• Today’s report is different
• What constitutes a big bore?
• The one unified law
• Respect for game
• Big bore airguns are very different
• There are exceptions
• A big truth about big bore bullets
• Hydrostatic shock
• Why you need to know this

Today’s report is different
Today’s report will be different. I put it in with the Texan rifle because that’s the big bore we’re currently looking at, but it really applies to all big bore airguns, alike.

I’m going to discuss how a big bore airgun kills game. This will be a detailed discussion that may not be suitable for people who feel uncomfortable reading about or talking about killing animals.

What constitutes a big bore?
I’m asked this question all the time. What makes an airgun a big bore? I started answering this question before many others even knew what big bore airguns were, and I’ll continue to answer it in this same way. There are 4 common smallbore calibers — .177, .20, .22 and .25. Anything larger than a .25 is a big bore. Sounds simple, but it invites the barracks lawyers to chime in. There are airguns today that shoot .257-caliber conical bullets, and isn’t a .257 technically a .25? Yes, it is. This is where my simple definition breaks down a little. If you can’t remember this one anomaly, I guess you’re lost.

But there’s more to it than that. A hundred fifty years ago, hunters had no difficulty understanding that a rifle that shot .40-caliber balls or larger was suitable for hunting whitetail deer. In a pinch, they would even use a .38-caliber rifle, but .40 caliber was the place they wanted to be for large, thin-skinned, non-dangerous game. You won’t find this written in any book that I know of; but if you read a lot of shooting history, it’ll come out.

So, the hunters of old knew that the bottom line for a rifle for larger game (the smallest you could use and expect success) was around .40 caliber. And .45 caliber was even better. When the ball got that large, there was no mistaking where things stood.

Then, conical bullets came along (1860?) and muddied up the water. Suddenly, a .32-caliber rifle shooting a heavy conical bullet (like the .32-40 in 1884) was sufficient for deer, but a .38 caliber shooting conicals (the .38-55, about the same time) was even better. And, just when that was being digested by the sporting public, smokeless powder came on the scene and bullet velocities doubled. At that point, .30-caliber rifles (like the .30-30) could take deer; and, soon, even .25-caliber rifles (such as the .25-35 Winchester) were considered marginal.

The one unified law
Many of today’s shooters don’t even know what a .25-35 Winchester cartridge is. Yet, they want one unified definition for a big bore airgun. Well, here it goes: There ain’t none! No single definition can be applied — especially, if the people applying it refuse to understand basic ballistics. If they think that the title “big bore” conveys some mystical killing power to any airgun, they’re sadly mistaken. Yes, I can tell you what a big bore airgun IS, but that, by itself, tells you very little about what it can DO. To know that, we have to understand how game is killed.

In the olden days, a .40-caliber ball was considered big enough to take deer — not because of its energy, which was almost nil, but because of its size. And projectile size is what I’m going to talk about today.

Respect for game
When I studied for my German hunting license in the 1970s while serving there in the U.S. Army, I learned how much the German hunters respect the game they kill. Besides learning a specialized vocabulary of German words that apply only to hunting and demonstrating proficiency with a rifle, we had to know how to treat game with respect. For example, whenever I killed a roe deer, I put a sprig of pine in its mouth as a ceremonial “last bite.”

Sure, such things are for the hunters and not for the game whose lives have already been taken, but what they do is remind the hunter that this was a living being that enjoyed life until the end. I think these small ceremonies keep most hunters from becoming crass. That has everything to do with today’s discussion.

Big bore airguns are very different
Most hunters are surprised when they shoot a game animal with a big bore airgun. They’re surprised because the animal doesn’t fall down at the shot. Typically, they stand for several minutes where they were hit…as they slowly expire (die) from blood loss. It’s so different from anything they may have experienced while hunting with modern firearms.

When a large game animal is hit with modern expanding bullets traveling at supersonic speeds, it can drop instantly in its tracks. Granted, that doesn’t happen often, but it does happen. At the very least, a well-hit animal that’s hit with a modern expanding bullet only runs a short distance before piling up. Thirty seconds is usually the longest you have to wait before it will drop — when the animal has been hit well. Modern centerfire bullets have caused hunters to expect quick results that big bore airguns do not give and cannot give.

Hunting with a big bore airgun is very similar to hunting with a muzzleloading rifle that shoots lead balls or bullets — not one shooting modern jacketed softpoints with sabots. It’s also similar to hunting with a bow. The game often stands in one place, looking around like it hasn’t been hit. Or if it does run, it runs fast and far and has to be tracked. The secret is to not follow the game right away. After the shot, wait about 10 minutes for the animal to stop running and start stiffening up. They will usually bed down at this point and will not be able to get up again.

There are exceptions
Of course, there are exceptions to what I’m saying about modern bullets and game. I’ve had them happen to me — animals that appear to be hit well, but last much longer than they should. The hunting archives are full of stories about game that refused to die. But you have to recognize these for what they are — exceptions to what usually happens. In general, a modern bullet of the correct size and power will very quickly dispatch an animal that is hit well.

A big truth about big bore bullets
Here’s a truth that escapes many modern hunters. A .45-caliber lead bullet generating 250 foot-pounds of energy will kill a medium-sized animal like a whitetail deer just as dead in the same amount of time as a .45-caliber lead bullet that generates 1,500 foot-pounds of energy. That’s because most of the more powerful bullet’s energy is not expended in the animal—it slips right through and keeps on going! Most of the energy is excess to your needs.

Unless there’s a large bone in the way, or the animal has a particularly tough hide, you don’t need to hit it with a lot of energy. These heavy lead bullets don’t kill with their energy — they kill with blood loss. This is why relatively light round balls kill large game so effectively.

New big bore hunters are fascinated with hollowpoint lead bullets — thinking that the expansion of the bullet inside game transfers more of the bullet’s energy to the animal. But it isn’t the energy that kills — it’s the loss of blood. So, a .45-caliber solid bullet will kill just as fast as a hollowpoint bullet that mushrooms out to .75 caliber. Once the hole in the animal is big enough, it doesn’t make much difference if it grows any larger. The damage has been done.

What I’m leading up to is this — a 405-grain .458 bullet is fine for the largest game. If I think I need it to penetrate a heavy bone or a thicker hide, the 405 is the way to go. But if I’m hunting thin-skinned whitetails or something similar (javelinas, coyotes, mountain lions, etc.) I want a much lighter bullet that has the advantage of a flatter trajectory.

The 405-grain bullet would be perfect for American elk (wapiti), red deer and bison. We know from actual field experience that it will pass completely through even these massive animals when it impacts on one side, such as with a classic heart/lung shot. That happens even when the bullet is fired from a 500 foot-pound rifle. Then, the process of bleedout begins and the animal drops several minutes later, when blood loss has its effect. This is something archers understand all too well. But many who come into big bore airguns from the firearm side are used to hydrostatic shock.

Hydrostatic shock
Hydrostatic shock is the shock wave that passes through the liquid-filled tissues of an animal when hit by an ultra-high-velocity bullet. This shock wave is devastating to the animal’s nervous system and can sometimes cause near-immediate death. Many hunters are so accustomed to this effect that they cringe when they see how long it takes a bullet from a primitive rifle or an arrow to drop an animal. That slow performance is exactly what you can expect from a big bore airgun bullet.

Why you need to know this
Today’s report is one I’ve held off writing for a long time. I know that many people feel they would like to learn to hunt, and big bore airguns are starting to appear like an easy way into the sport. That’s fine — as long as you know what you are getting into. At the end of your hunt, an animal is going to die and it’s going to take a long time to do it — especially if you’ve hunted only with modern centerfire rifles, or the only hunting you’ve ever seen is what’s on television.

Believe me, the hunting shown on television is heavily edited! If the game happens to drop instantly when shot, they show it — but if not, they edit in some tracking, along with conversation to get your mind off what’s really happening. If it takes 12 minutes for an animal to die, you will only see about 20-30 seconds of that. I happen to agree with that approach, because people don’t need to see the suffering in their living rooms.

But, if you decide to go out into the field to hunt, then I want you to know what you’re going to see. I hunted extensively when I was younger, and everything I’ve described in this report I’ve seen many times over. But I’ve also seen a first-time hunter confronted by the truth. And he was shocked. That wasn’t pleasant.

Talk all you want about hunting with a big bore airgun — we won’t limit that in this blog. Just understand that when you do decide to hunt with one, the results will probably look a lot different than you might have imagined.

AirForce Texan big bore rifle: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

Texan big bore
The Texan from AirForce Airguns is a .458 big bore to be reckoned with. The 4x scope and bipod are options.

This report covers:

• Starting to test accuracy
• Scope swap
• On my own
• The best bullet
• Yada, yada, yada…
• At 100 yards
• Summary

When I ended the last report, I said there was a lot more to say about the new AirForce Texan and that I would get to it in the next report. Today, I’m going to talk about accuracy, which all of you want to know about. This will be a complete report; but even when I finish, there will still be more to tell. I have a special report coming about the effectiveness of big bore air rifles on big game in general, and I’m sure that one will evoke a lot of discussion.

Starting to test accuracy
I began testing the Texan from my past experience with other big bore air rifles. I knew that guns that developed around 200 foot-pounds of muzzle energy may get up to 10 shots per fill of air, but those that generate above 300 foot-pounds usually get just 2 good shots per fill. I knew the Texan was a 500 foot-pound gun, so I started testing from that assumption. I would shoot 2 shots and then fill the gun again, and so on.

Texan big bore at AirForce
Before I tested it, I shot the Texan at AirForce several times.

Scope swap
Early in the testing, I removed that 4x scope that Airforce mounted on the rifle and mounted an obsolete scope that’s a lot like this UTG 4-16X56. The 4x scope was unclear at 50 yards (fixed parallax set for 100 yards), and I needed all the aiming precision I could get. The UTG scope gave that to me.

On my first trip to the range, I didn’t have the chronograph, and all I was concerned with was whether or not the Texan was going to be accurate with the bullets I was shooting. I’d already fired the rifle many times over at the AirForce plant, but the range we shot at over there was only about 25-30 yards; and I was now shooting at a 50-yard range at my gun club. Plus, I always shot their bullets. Now, I would be shooting my own.

Every time I shot the rifle at AirForce, it was deadly accurate. One time, shooting offhand, I put three rounds into the same hole at this distance, which is way out of profile for me. Another time I hit a dime-sized circle of Tannerite to trigger an explosion for a video that Ton Jones was filming. I knew the rifle was very accurate. But how good would it be with my own bullets?

On my own
The first bullet I tried was a 405-grain .458 lead slug that I cast myself. This is the bullet I shoot in my 45-70, as well as in my Quackenbush .458 Long Action Outlaw. I knew it was accurate in both those guns, so I felt it was a safe place to begin.

I did not understand the Texan at this point, so I just filled it to 3,000 psi and fired 2 shots per fill. The first 10-shot group at 50 yards measured 3.159 inches between centers. I was happy with this because it was the first attempt. However, on this same day, I also had some Tin Starr 405-grain hollow base bullets, so I shot a second group with them. Ten went into 2.071 inches at the same 50 yards. Now, I was excited! Simply by changing bullets, I had shaved 1.088 inches off the group size! And, I was just beginning!

Texan big bore my 405
Ten of my cast 405-grain bullets made this 3.159-inch group at 50 yards.

Texan big bore Tin Starr 405
Ten 405s from Tin Starr went into 2.071 inches at 50 yards. That’s much better!

The next time I went to the range, I went with 6 different Tin Starr bullets and a chronograph. On that first day, I’d noticed that when I filled the rifle after 2 shots the pressure was sitting at around 2500 psi. That means the rifle used only about 250 psi for each shot. The norm for a gun of this power is 500-750 psi per shot.

The best bullet
Next, I was fooling around with some of the lighter bullets — the 215-grain semi-wadcutters to be exact — and that’s when I did it. I shot 6 shots through the chronograph to see what would happen and got the following results:

Shot 1 — 835 f.p.s.
Shot 2 — 899 f.p.s.
Shot 3 — 881 f.p.s.
Shot 4 — 870 f.p.s.
Shot 5 — 856 f.p.s.
Shot 6 — 830 f.p.s.

When I filled the gun, it still had about 2,000 psi in the reservoir, so these 6 shots were not taking very much air at all. I’d adjusted the bullet tuner before switching to this light bullet, and apparently I got it just right.

Then, I shot 5 shots at 50 yards with the 215-grain semi-wadcutters. I shot all 5 shots on the same fill. They landed low and left in a group measuring 0.762 inches between centers! That was astounding! The Texan was clearly different than the other big bores I was used to.

Texan big bore best group 50
At 50 yards, I managed to put five 215-grain bullets into 0.762 inches. This was clearly a good bullet!

Yada, yada, yada…
Once I discovered how economical the rifle was with air, I started shooting it a lot. I mean, I shot 50-100 shots every time I went to the range. I tested every bullet Johnny Hill of Tin Starr bullets gave me, which is how I found the 4 that were the best. Those were mentioned and shown in Part 2 of this report.

My friend Otho also shot the rifle several times, as did another friend, knifemaker Tank Fisher. Tank found the Texan easy to load and shoot, and both he and Otho did very well with the 405-grain Tin Starr bullets. Though the 405s are great, the 215-grain semi-wadcutters are even better. I saved them for myself, since they were the most accurate of all and I had a serious test to complete.

Texan big bore Tank
Tank Fisher gets down on the Texan at 50 yards. Off to the right of the 50-yard berm is the 100-yard target berm, and to the right of that you see the 200-yard berm.

I shot the rifle so much that I actually ran my 88 cubic-foot carbon fiber tank out of air each time I went to the range! That was a new experience. I had to refill the tank before I could go back to the range again. In the past, this tank has lasted for at least a month of heavy PCP testing — but before now, I never shot a big bore this much. I had all the bullets I could shoot from Tin Starr, and the Texan is so easy to load and shoot that it was like shooting a smallbore — except for the size of the holes!

I have several more small 50-yard groups I could show you. However, at this point in the testing (with over 200 bullets downrange), I began to wonder about the rifle’s possible accuracy at 100 yards. I was up against a deadline for Shotgun News. I had to complete the article I was writing by the end of November.

At 100 yards
I did try the 405-grain bullet at 100 yards, but the best it could do was put 10 of them into about 3 inches. That’s better than I have ever done with a big bore air rifle at 100 yards, but it isn’t the best the Texan can do.

On the last trip to the range, I stapled a couple targets at 100 yards and set about to see what the 215-grain semi-wadcutter could do. At first, I shot 6 shots per fill. As I did, I noticed that shots 2 and 3 always landed very close to each other. I wondered what would happen if I shot a group that had several shot numbers 2 and 3 (after a fill)? So that’s what I did, and that’s what I’ll show you now.

I filled the Texan and fired a single shot three times. Then, I shot 2 carefully aimed shots at the 100-yard bull. When I finished, there were 6 holes that measured 1.506 inches between centers. That’s 6 shots in 1.50 inches at 100 yards. That was my best target of all.

Texan big bore best group 100

That ended my time with the Texan. I had just one day to get the rest of the article put together so Edith could edit it before I sent it in. Remember, we measure from the center of the 2 holes farthest apart. That equals 1 bullet radius (center to edge equals one radius). So, subtract one bullet diameter (.458″) from the measurement shown on the calipers.

AirForce needed their rifle back for other writers to test, so I had to give it up. There were only a few hand-built Texans in existence at this point in time, and the demand for them was enormous. Seldom, if ever, have I been so sad to see an air rifle go back to the manufacturer.

Let’s look at what we’ve learned about this rifle to this point. First, it has a unique new valve that operates on 3,000 psi air. It does not respond well to over-filling. Next, it has a bullet tuner that must be adjusted for each weight of bullet that’s fired if you hope to get the best results from the gun. This tuner is not the same as a power adjuster, though that’s exactly what it does.

The Texan is very easy to cock and load and uses less air per shot than most guns of similar power.

Finally, I learned that it isn’t the big heavy bullets that are the best in the Texan — it’s that 215-grain semi-wadcutter! I want to talk about that with you in the next part of this report, so stay tuned.

How are airguns designed?

by Tom Gaylord
Writing as B.B. Pelletier

AirForce Texan big bore air rifle: Part 1
AirForce Texan big bore air rifle: Part 2

This report covers:

• How the Texan was designed
• Establish the power baseline
• Accuracy
• Tradeoffs
• Testing
• The point
• Last point

I’m excited about today’s topic because it gives me a chance to do many things I’ve wanted to do. I linked this blog to the AirForce Texan because today’s topic arose from a comment posted to that report. Blog reader Kevin Wilmeth said the following.

“I would presume from that [my comment that the 34-inch barrel was selected by AirForce for several good reasons], that AirForce had their performance target identified beforehand, and built the barrel to fit it.

And I’m absolutely with you on kinetic energy having some significant limitations as a measure of hunting performance on medium game. I look forward to what’s coming!”

Kevin, you’ve been inside my head! You’ve made 2 really good comments here — each of which deserves an entire blog report to answer. I will address the comment about kinetic energy in a future report. Today, I want to talk about how airguns are designed.

How the Texan was designed
I was not a part of the Texan design team, but I did participate in the early testing of the rifle and did discuss the gun’s design with AirForce engineers at some length. Let’s start with the power.

Establish the power baseline
Dennis Quackenbush has pretty well established where the big bore muzzle energy bar needs to be set with his Outlaw Long Action rifles. To date he’s built and delivered over 1,600 of them. Compare that to the small handfuls of guns that other boutique big bore airgun makers have produced, and it’s easy to see that Quackenbush is the long pole in the tent. His .458 rifles produce around 500 foot-pounds. Yes, there are other big bores that produce even more energy than that, but as I’ve said, they aren’t being made in the numbers that Dennis’ rifles are. So, 500 foot-pounds is the established benchmark.

What about the Korean big bore guns, you ask? Haven’t they sold in even greater numbers than Quackenbush’s rifles? I really don’t know the answer, but I suspect they have. But the Korean guns have several drawbacks. First, they max out around the 200 foot-pound mark, give or take. And second, they are made with 0.451- to .452-inch bores that can only use pistol, bullets (.45 ACP bullets). Those bullets are ideal for 200 foot-pounds, but they’re not heavy enough to achieve the 500 foot-pound level we’re talking about.

Yes, those rifles will kill deer — that isn’t the question. The question is: What power level do American airgunners want from a big bore air rifle? The answer is 500 foot-pounds. If you don’t understand that, then the rest of today’s report will not make any sense.

I guess I’m saying that the energy level of a .458 big bore airgun has been established by convention — in the same way that the .223 Remington/5.56mm cartridge is so widely accepted by American hunters — despite its weak ballistics. Ten million ARs can’t be wrong!

Okay, so with the energy established, the next thing AirForce was after was accuracy. What do you expect from a .458 big bore air rifle? The couch commandos want half-inch groups at 100 yards, while the hunters are willing to settle for 3 inches. But if you’re about to launch a brand new big bore that you’re betting the farm on, you want to attract as many buyers as possible. So, how much accuracy is enough?

This is where the 34-inch barrel comes into play. AirForce tested other barrel lengths, and at close range all of them were acceptably accurate. But at long range, which I’ll now define as 100 yards and beyond, the 34-inch barrel had an edge. They figured that 100 yards would become the new standard, if it isn’t already.

Now, guess what length is the the maximum length that a barrel can be rifled with technology that’s affordable? Time’s up! If you guessed 34 inches, you would be wrong. As it turns out, 34 inches is beyond the capability of most rifling machines. I’m not saying it can’t be done. I’m saying that those companies that make rifle barrels and have hundreds of thousands of dollars invested in their barrel-making machinery can’t do it. Or at least they aren’t doing it.

Figure 80 percent of the barrel makers in the world can’t or won’t produce a 34-inch barrel. I’m not talking about old Zeke Graybeard up in Buzzard Hollow, West Virginia, who makes flintlock barrels that are 48 inches long. Zeke can make 34-inch barrels in his sleep. Takes him about a full day to make one barrel, and he charges $300-500 to do it. When AirForce comes along and wants to buy 500 barrels, old Zeke looks at the calendar and says he probably won’t live long enough to make them all. And AirForce needs those 500 barrels delivered over the next 6 months! So the Zekes of the world are out as far as suppliers of barrels for AirForce are concerned.

Now, Remington can turn out a barrel every 3 minutes on each of their 41 hammer-forging machines. And those machines can accept a mandrel (a hardened steel rod with a negative impression of the inside of the barrel) of up to 26.25 inches in length. You want to buy 500 34-inch .458 barrels from Remington? Fine, just give them $250,000 to install a specially built hammer-forging machine that can accept the longer mandrel, and, oh yes, you’ll have to pay to have that mandrel made, as well. Figure $400,000 to set them up to make your barrels.

Are you seeing where this is going? There just aren’t that many places that can supply 34-inch barrels. You can argue this point all you want and send me links to companies that supply barrel liners — I’m telling you what AirForce just went through to get 34-inch barrels for the Texan.

Okay, let’s say you locate a source of 34-inch barrels. What’s the ideal rifling twist rate for your new rifle? Well, the “books” say a lot of things, but the only way to know for sure is to test them all. So, that’s what AirForce did. I thought a 1:18″ twist would be the best, and they thought it would be either 1:20″ or 1:22″. In the end, the 1:20″ twist seemed to work the best. But it was a compromise of many things.

A faster twist means more rotational friction on the bullet and slower velocities. A slower twist gains velocity but may not stabilize longer, heavier bullets out at longer ranges. What do you do? What if there’s a super-accurate bullet that weighs 300 grains and produces 415 foot-pounds in a 1:22″ twist barrel, but the 1:20″ twist barrel will also handle a 405-grain bullet and get you 500 foot-pounds, while it’s only a little less accurate with the 300-grainer? These are the kinds of decisions AirForce had to make with each design change they made — and there were hundreds of them!

And, really, when you get down to it, tradeoffs are a major part of design work. The first thing is to figure out how to make something work, then you have to figure out the best way to make it work and finally you have to figure out how to produce whatever you came up with.

So, the design is underway, and you have a prototype built. Now, it’s time to test it. Here’s a good question: How do you know during testing whether the person doing the testing is any good, or if he’s more of a hindrance than a help? How do you know the test is being done right? Well, the fact is — you don’t. Your head engineer may also be a lousy shot! You hope not, but that does happen. What you need are many tests by several people. To get that, you need to build several rifles — not just a single prototype. And it goes on and on ad nauseum.

The point
I am going to stop here and make a huge point. Some readers may have thought that all this development work was done on CAD computers by a phalanx of scientific types in white lab coats. In fact — that’s an inside joke among airgun manufacturers! There is some of that, but what you’ve read to this point is by far the more accurate description of how this process unfolds. There ain’t no board of governors that writes up all the performance parameters so you know exactly what has to be built. It’s people like you and me making educated guesses. But the difference is that when these folks guess wrong, whole companies go out of business. So, people who have a record of guessing right are listened to, and the blue-sky dreamers are tuned out.

The other day someone asked me on this blog how far a bullet from a Texan would travel, and I guessed a 405-grain slug might travel between 1,500 and 2,000 yards. Right away, I was criticized by another reader who informed me there was no way a subsonic bullet could possible travel that far.

When I made that “guess,” I had in mind the 1992 Army experiment done at the Yuma Proving Grounds that used millimeter wave radar to track the flight of blackpowder bullets fired from buffalo rifles of the 1870s. A forensic scientist at Yuma had written a paper that claimed it would have been impossible for buffalo hunter Billy Dixon to shoot an Indian off his horse at 1,538 yards (at the second battle of Adobe Walls, June1874), because the 50-90 Sharps rifle he used could not shoot that far.

Well, the Army scientists discovered in this test that subsonic bullets will not only shoot that far, but many times farther! And my prediction of the range the Texan will shoot a 405-grain bullet turned out to be conservative. According to blog reader JimQwerty123, Chairgun software says it will shoot to beyond 2,300 yards.

The point is that I make guesses, but usually they’re based on my experience. Yesterday, I admitted to blog reader Claude that I was wrong about the penetration potential of a BB fired from the Colt Single Action Army revolver, so I’m not always right. But when I’m advising a manufacturer like AirForce on a project, I know how high the stakes are and try very hard to minimize any mistakes. If it’s a question of personal taste, like what I think of black rifles, I tell them my prejudices up front. But when it comes to what will work, and more importantly, what will sell in today’s airgun market, I’m very careful about what I say.

Last point
In 2006 I took an idea for a precharged airgun to Crosman. They were not in the precharged airgun business at that time, and in fact they had made some marketing blunders by rebadging certain European precharged guns in their recent past. But I knew they wanted to get into the precharged arena and thought I had the ideal vehicle to do that.

So, I made a PowerPoint presentation to them at the SHOT Show that outlined a precharged rifle I thought they should build. I thought it should fill to a maximum pressure below 2,000 psi to make it easier to fill with a hand pump. And there were a host of other performance parameters I thought it should have.

But I went farther than that. I felt Crosman should use this simple PCP to build their internal manufacturing capability to make PCP airguns in general. Stop buying from other companies and make them right there in-house.

I was met by a lot of skepticism. A 2,000 psi fill — was I out of my mind? Didn’t I realize that a .177 air rifle HAS to shoot 1,000 f.p.s. to be successful? I said that I did realize that, and that my rifle could do that on 2,000 psi air. I knew it could because I owned a USFT rifle that shot heavy .177 Kodiak pellets at more than 900 f.p.s. and got 55 shots on one 1,650 psi charge of air. But they weren’t sure.

A month later they flew me in to New Bloomfield, NY, to discuss the project further. I carried a device in my suitcase that I was going to use to demonstrate the possibility of my idea. It was a hose with an inline step-down regulator that attached to a scuba tank on one end and a Benjamin AS 392T CO2 rifle on the other. I would demonstrate how an air rifle could do all I’d promised right there in their war room (that’s what they called their conference room).

But I didn’t have to. Crosman has an engineer named Ed Schultz, who’s forgotten more about airguns than most engineers will ever know. In the month between our conversations, he’d prototyped two Crosman 2260 rifles — one in .177 and the other in .22 — and had them shooting exactly as I’d promised. Not only was the .177 getting 1,000 f.p.s. — it was also getting more than 20 good shots per fill!

Folks, on that day I was received like Moses pointing the way to the promised land! Every executive at Crosman was now convinced that this was the way to go and the rest of the story — well, that rifle became the Benjamin Discovery.

So — Kevin Wilmeth — do you see what you did? You scratched my itchy spot, and I had to respond. Airguns are designed in a number of different ways. Some are as simple as sitting down with a Chinese airgun factory and selecting models from their catalog, then adding the features you desire. The biggest decisions to be made are the graphics that will go on the outside of the box.

What I just described for you is the real way airguns get designed. Someone has an idea, and a lot of work is done to turn it into something nice. Just be sure you know what “nice” is before you spend the time and money to get there!

AirForce Texan big bore rifle: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Part 1

Texan big bore
The Texan from AirForce Airguns is a .458 big bore to be reckoned with. The 4×32 scope and bipod are optional accessories.

Note: I just found out the scope is not included with the Texan. I’ve added a note to part 1, where I originally mentioned it was included.

This report covers:

• Power
• Air pressure
• The bullet weight tuner
• The bullets
• Using the bullet tuner
• Maximum power

Before I begin, I’m asking the organizers of airgun shows around the country to please send me their show information. Several readers have asked me for this information, and we need to publish it in a place everyone can find. The North Central Texas airgun show will be held at the Parker County Sportsman Club in Poolville, on Saturday, August 29. Send your airgun show info to [email protected].

Today, we’ll look at the AirForce Texan big bore rifle in closer detail. Part 1 was just an introduction to this interesting big bore. It stirred up a lot of interest, but after seeing all the other new big bores at the SHOT Show and listening to the conversations about them, I know I need to describe this one more precisely.

First, let’s talk about power. Most big bore air rifles don’t produce more than 200 foot-pounds of muzzle energy, and a couple of them are closer to the 100 foot-pound mark. There’s nothing bad or wrong with that, except when people start using the term big bore indiscriminately — as though it defines power. Then, things get confused.

During our roundtable discussion while filming American Airgunner at the show, Jim Chapman said he would like to see the term “medium bore” used to describe those guns that are larger than .25 caliber but still have lower muzzle energies. He never specified what the power cutoff would be for that term.

I was opposed to that idea. My feeling is that the term big bore describes the bore size, only (all airguns with bores larger than .25 caliber are big bores), and the energy potential has to be addressed separately. I feel that trying to create special labels to categorize airguns gets us into trouble. It’s where confusing terms like “hard air” (a meaningless term for pellet and BB guns made up by those who also sell airsoft guns) come from, and it’s the reason why young people who are not shooters are calling bolt-action repeaters single-shots because something has to be done manually (working the bolt) before each shot.

I’m using the tern big bore for all airguns with calibers greater than .25. And the guns that shoot .257-caliber bullets (instead of diabolo pellets) fall into the big bore category for me.

The Texan produces a potential of more than 500 foot-pounds, depending on the bullet used. And, today, you’re going to see what a broad range of power a gun like this has. So, to understand what I’m talking about, we’ll define the gun by its power potential and forget the fact that it’s a .458 caliber. There are other .45-caliber air rifles that barely produce 200 foot-pounds. Anything I say about the Texan does not also hold true for them.

Air pressure
In Part 1, I told you the Texan is a remarkable new air rifle. Now, I’ll tell you exactly why. All other big bores that achieve 500 foot-pounds of muzzle energy and more use air at a pressure above 3,000 psi — except for the Quackenbush Long Action Outlaw. The Texan and the Outlaw, alone, are able to make 500 foot-pounds on just 3,000 psi.

If the whole truth is told, you can fill a Quackenbush rifle above 3,000 psi and get a little more energy from it. Not so with the Texan. The Texan has a carefully balanced valve that does not respond well to over-pressurization. In fact, I’m about to show you that the Texan’s powerplant has to be tuned to the specific weight bullets you’re shooting. When I used pressures above 3,000 psi in my testing, the initial velocities fell off. And don’t think that you can add weight to the striker to overcome this. The valve, itself, is very carefully balanced and will not respond positively to home gunsmithing.

But this isn’t a negative! You are getting more power from less air than any other big bore airgun on the market. I will show that today, as well. So, if you’re going to get a Texan, do so with the mindset that AirForce has done everything right up front, and all you have to do is follow their instructions.

The bullet weight tuner
Usually, my feature articles in Shotgun News are good because I have unlimited space to explain things in detail and show detailed closeup photos. But the article I wrote about the Texan was edited heavily and lost several key photos. The text explained what you’re about to see, but without the picture it didn’t make much sense.

The Texan has to be tuned or adjusted for the weight bullets you’ll be shooting. That’s because the valve takes the bullet weight into account in a way that may seem counterintuitive. Usually, when we think of more power in a pneumatic, we think of increasing the striker weight or the tension on the striker spring. But that’s exactly the wrong thing to do with a Texan! When you want to use a heavier bullet in the Texan, you need to DECREASE the striker spring tension. That’s because the heavier bullet remains inside the barrel longer, providing back pressure that also holds the valve open a little longer.

Texan big bore bullet tuner
This wheel on the left side of the frame is for tuning the powerplant for various bullet weights. It’s not precise. AirForce left off the numbers because they don’t want people to obsess over certain settings. The marks are just for general reference. Read the text where I describe it.

You’ll notice that the bullet weight tuner has no numbers. It’s just a simple wheel with a few lines for reference. That’s because people tend to obsess over the exact settings on other AirForce guns, and they discuss them as if they’re absolute and carry over from one gun to another. You read about people arguing whether they should shoot an 18.1-grain pellet with a power wheel setting of 12.9, or 12.4, when the truth is that each gun is unique unto itself. What works for one rifle won’t work the same for another.

The Texan’s bullet tuner works in a similar way. It’s not really a power adjuster. It simply compensates for the length of time a specific (weight) bullet will remain in the barrel. You make large changes when shooting bullets of a different weight. Small changes on the wheel don’t really matter that much. I’ll explain more in future reports, but right now I’m going to talk about the bullets that were tested.

The bullets
I started shooting the Texan last July, when there was only one working prototype. As the months passed and small changes were made, the rifle’s performance also changed. AirForce experimented with many different lead bullets, barrel lengths and rifling twist rates — as well as some other projectiles like sabotted bullets and round balls.

Texan big bore bullets
These are a few of the bullets AirForce used when testing the Texan.

About this same time, Johnny Hill, one of the owners of Tin Starr bullets in Weatherford, Texas, (817-594-8511 [email protected]) discovered AirForce airguns and became a dealer. Tin Starr is a company that makes lead bullets for cowboy action shooters, and Johnny asked me what bullets I thought might do well in the Texan. I thought the rifle should do well with a 405-grain slug, but Johnny thought that some pistol bullets might also do well if they were cast and sized as 0.458 instead of the 0.451/.452 size that pistol bullets usually are.

He made several custom molds and hand-cast several hundred pure lead bullets for my testing. Of the different shapes and weights he supplied, 4 stood out as extremely accurate in my test rifle. When I started testing, I thought my own cast 405-grain bullets might do the best, but mine are slightly harder than pure lead (mine are a hardness of 6, where pure lead is a 5). Tin Starr has discovered how to cast pure lead and still get bullets that are well filled out — something that’s supposed to be impossible.

Texan casting bulletss
Several hundred custom bullets were hand cast and sized for my tests.

Texan my 405 and Tin Starr 405
The three on the left are my 405-grain .458 bullets. Three 405s on the right are from Tin Starr. They are hollowbase bullets cast from pure lead.

As the test progressed, it became obvious that the Tin Starr pure lead bullets were the way to go. My 405, which does well in my Quackenbush rifle, could not stand up to the Tin Starr 405 hollowbase.

Texan Tin Starr bullets
These 4 Tin Starr pure lead bullets were the best of all the bullets I tested. From the left, they are 405-grains, 350-grains, 240-grains and 215-grains.

Using the bullet tuner
When I picked up the rifle from AirForce for my test in October, I was given a lesson in how the bullet tuner works. The engineer set up the rifle to work best with round balls, but he showed me the setting for heavier bullets. I was also shown how to uncock the rifle, which is surprisingly easy. You just open the cocking lever all the way, then return it about 3/4-inch so the safety can be taken off and pull the trigger. There’s not so much as a pop of air! The striker returns home, and the gun is uncocked.

Once I got to the range, I adjusted the bullet tuner for the 405-grain bullet first. I thought it would be the most accurate because it is in my Quackenbush. And, now, I am going to condense 3 or 4 trips to the range into a single table for you. But before I do, let me tell you about the big surprise I had when chronographing the bullets.

For some reason, I decided to chronograph the 215-grain semi-wadcutter first, so I filled the reservoir to 3,000 psi and fired through the chronograph. I got the following velocities.

Shot    Velocity (f.p.s.)
1           835
2           899
3           881
4           870
5           861
6           830

After that, the velocities dropped off rapidly, but there are 6 powerful shots on a single charge of air! In later testing, I got slightly different numbers than these, but the 215-grain bullet averaged 880 f.p.s. (for the first 2 shots), for an astounding muzzle energy of nearly 370 foot-pounds.

Up to this point, I’d been shooting the Texan with just 2 shots per fill — the same as any other big bore in this power range. I really didn’t understand how the Texan performs until I shot this string. It showed me that, at least with these lighter bullets, the effective number of shots is really 6. What a difference that makes, because this bullet is perfect for whitetail deer.

However, when I tested the rifle for its maximum power, I used the best 2 shots per fill. That way, I’m testing it against all other big bores that get tested the same way. And I did confirm that, with the heavier bullets, 2 shots are all the useful full-power shots you get on a fill.

Maximum power
The following table was developed by tuning the rifle for each bullet weight. Only the first 2 shots froim each charge were used to make this table.

Texan performance chart

There’s much more to tell, and we’ll get to it in the next report. Until then, stay tuned!

AirForce Texan big bore rifle: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Texan big bore
The Texan from AirForce Airguns is a .458 big bore to be reckoned with. A 4×32 scope comes with the rifle, but the bipod is an option.

I found out after this was published that the scope is not included with the rifle.

This report covers:

• AirForce builds a big bore
• Cocking mechanism
• The trigger is gorgeous!
• Much more to come

The 2015 SHOT Show begins today, and our subject rifle is being revealed to the shooting industry. This is the airgun I have been teasing you with for the past 3 months. It’s a .458-caliber big bore from AirForce Airguns called the Texan.

I first shot this rifle while it was in early development last year. I was impressed by the accuracy, light weight and power; but the cocking effort was difficult. That got fixed so well that this has to be the easiest-cocking big bore on the market. You can cock it with one finger! But I’ll come to that. Let’s look at this remarkable new air rifle.

AirForce builds a big bore
The Texan is a .458-caliber single-shot rifle that cocks via a sidelever located on the right side of the frame. It weighs 8 lbs., 3 oz., which is light for its caliber and power. Given the physics involved, you can expect a fairly sharp kick when the rifle fires. It’s not heavy, but you’ll know something has happened.

The rifle is long, at 48 inches overall. The 34-inch barrel accounts for a lot of that, and I’ll explain the reason for such a long barrel in a bit.

In AirForce fashion, the reservoir is also the butt of the rifle. Although it can be taken off the gun, it normally remains in place all the time. There’s a fill nipple on one side and a small pressure gauge on the other. The pull is adjustable, from 13-7/8 inches to about 15 inches via a sliding buttplate. The buttplate can also be rotated to the right or left for some cast-on and cast–off adjustability.

The frame of the rifle is aluminum, anodized in a non-reflective matte black surface. The long, thin barrel sticks out the front of the frame an additional 9-5/8 inches.

Cocking mechanism
The cocking mechanism deserves some explanation. On the first prototype, there was no mechanical advantage and the sidelever was very hard to cock! I remember thinking they would never get past it, but when I tested the rifle again several months later, the effort had vanished!

Texan big bore prototype cocking lever
An early cocking lever prototype used two anchors. It worked well, but was too complex to manufacture. However, it proved the engineer’s design, which was developed on the CAD system.

The Texan was designed on a computer-aided design (CAD) system. That saves time in many ways. It’s possible to operate some parts while they are still just concepts on the computer when a system like this is used. And, when a design seems good, the instructions to make the parts can be sent electronically from the designer to the CAD-driven machinery that will make them.

Texan big bore CAD
The engineer is able to build parts and test them on his CAD workstation.

This is not new technology, but using it effectively is something that one company might do better than another. AirForce is heavily invested in such systems; and as a result, they don’t spend as many man-hours in the machine shop when it’s time to build something.

Texan big bore cocking lever closed
The final sidelever mechanism has a single anchor point and fulcrum. It works as easily as the earlier prototype and is much less expensive to make.

Texan big bore cocking lever open
The final sidelever mechanism has a single anchor point and fulcrum. It works as easily as the earlier prototype and is much less expensive to make. It opens like this with almost no resistance.

Texan big bore cocking breech open
When the sidelever goes forward, it opens the breech like this. A bullet is then laid on the loading trough and pressed forward with the thumb as far as possible.

After loading a bullet, the sidelever is closed and you get another surprise. The lever goes back with very little effort! Somehow, AirForce has managed to take all of the cocking effort out of the process through perfect leverage! This act of cocking and loading the rifle, which is easier than cocking a Red Ryder BB gun, is so light and smooth that it sells the rifle to many who try it. My shooting buddy Otho told Yvette at AirForce that he wants to buy a Texan as soon as they come on the market.

The trigger is gorgeous!
Another thing that sold Otho on this rifle is the trigger. I can see why! It’s butter-smooth and light. But it’s a 2-stage sporting trigger — not a target trigger that’s adjusted too light. On my test rifle, the trigger broke cleanly at 33 oz. every time.

The safety is automatic, coming on when the rifle is cocked. It can also be applied at any other time. The safety blade comes back through the front of the triggerguard, where a forward flick of the trigger finger can take it off silently.

AirForce Texan
The trigger and safety will look familiar to AirForce fans. This trigger is light and crisp and the safety is a one-finger operation.

Much more to come
If you’ve already bought the color edition of Shotgun News that’s on the newsstands right now, you would see my complete report on the rifle. But I’ll put even more in this blog. Over the coming weeks, I’m going to reveal a big bore airgun that’s unlike any I’ve ever tested.

For instance, you can adjust the power, but it isn’t called that. It’s called “tuning for the bullet.” It works differently than any other power adjuster you’ve ever read about, because the valve in the Texan is unlike anything you’ve seen. I’ll get into that in Part 2.

For now, I’ll just say this. If you’ve been wanting a serious big bore airgun, by which I mean one that can take large thin-skinned game of bison and elk size, put this rifle on your short list. When you see the performance, you’ll understand why.

And I know that you want to know how much the Texan will sell for. I do, too.

Finally, there will be those who, upon reading about this rifle, will go off by themselves and start inventing entire new universes to live in. “When does it go on sale?” “Can you swap barrels?” “What other calibers does it come in?” “Can it be made into a shotgun?” And my favorite, “If evil alien machines threaten to take over the earth, will it transform into a giant superhero robot?”

All these things will be answered in good time, my friends. For now, let us bask in the glory of another fine big bore air rifle that’s coming to the market.