Big Bore airgun calibers

Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • The greater problem
  • The beginning
  • Bullets — not pellets
  • .308 caliber
  • Bore size
  • .357 caliber
  • Black powder
  • The .45 caliber dilemma
  • Shoot soft lead bullets that are slightly larger
  • Other big bore calibers
  • Summary

Most shooters are familiar with the smallbore airgun calibers of .177, .20, .22 and .25. Even shooters who don’t consider themselves to be airgunners know at least the .177 and .22 calibers. But in recent years there has been an explosion of big bore airgun calibers, and I am seeing that many shooters have little knowledge about them. If that were the only problem it would fix itself, because over time people always learn.

The greater problem

The bigger problem are the airgun manufacturers that do not know much, if anything, about the larger calibers. This report will address the lesser-known truths about big bore airgun calibers. read more


AirForce Texan: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Texan
AirForce Texan big bore.

Part 1
Part 2

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!
  • Velocity
  • One more velocity lesson
  • Summary

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?

AirForce Texan Ton Jones
|Ton Jones set up my .45 caliber Texan with the new carbon fiber tank and the TX2 valve.


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. read more


AirForce Texan: Part 2

by Tom Gaylord
Writing as B.B. Pelletier


AirForce Texan big bore.

Part 1

This report covers:

  • Why more air?
  • Why a big bore?
  • Texan operation
  • The big bores that fill to 4,500 psi
  • Big bore bullet philosophy
  • Cocking and Uncocking
  • Can it be uncocked?
  • Summary

In Part One I hopefully familiarized you with the AirForce Texan. Specifically I am talking about the .45 caliber Texan. AirForce and Pyramyd Air both call it a .457-caliber rifle, but it’s really a .458. Only bullets sized .458 and larger will be accurate.

These days you can get either this rifle or the new .50-caliber rifle with the standard 490cc tank that fills to 3000 psi and gets 3-6 shots, depending on the bullet fired and the power setting, or you can get the carbon fiber tank with the TX2 valve. That one fills to 3,.600 psi. The TX2 valve opens more to pass more air and it closes faster to conserve air better. It does use more air with each shot, but it also has more air. Expect 6 or more good shots from a fill to 3,500 psi. read more


AirForce Texan: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Texan
AirForce Texan big bore.

This report covers:

History
Here is the deal
No more energy is needed
The TX2 valve
Summary

Twenty-five years ago big bore airguns were the stuff of dreams. They existed as antiques in collections, but for those who lacked big cash, they were unapproachable. Then, in 1996, Dennis Quackenbush did something about it. He started building the .375-caliber Brigand. It shot .375-caliber round balls and was a bolt-action breechloader. It was powered by bulk CO2 gas and put the ball out the muzzle at around 675 f.p.s. I tested mine on 1100 psi air and got velocities of 800 f.p.s. and more.

History

What followed is history, First the Koreans jumped on the bandwagon, followed by the Turks. They made high-caliber big bores, but in terms of energy they put out half or less of what a really powerful big bore did. read more


The Benjamin Bulldog big bore: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4

Benjamin Bulldog
Benjamin’s new Bulldog bullpup big bore air rifle is a .357-caliber 5-shot repeater.

This report covers:

  • Pellets
  • H&N Grizzly pellets
  • JSB Exact King 35 pellets
  • Velocity for the King
  • Air Venturi round nose bullets
  • Velocity for the round nose
  • One more trip to the range?

Benjamin Bulldog Tom on bench
This was a good day to test the new Benjamin Bulldog.

I spent another day at the range with the

Benjamin Bulldog read more


The Benjamin Bulldog big bore: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Benjamin Bulldog
Benjamin’s new Bulldog bullpup big bore air rifle is a .357-caliber 5-shot repeater.

This report covers:

  • Tin Starr Bullets
  • Tin Starr 101-grain SWC
  • Air management
  • Tin Starr 108-grain truncated cone
  • Air Venturi round ball
  • Eun Jin 9mm domed pellets
  • Tin Starr 128-grain round nose
  • Back to the Tin Starr 101-grain SWC
  • Velocity
  • More to come

Thanks for being so patient on this report. I last looked at the Benjamin Bulldog .357 big bore air rifle on April 2. April was a very busy month for me and I had to put all trips to the range on hold. But I’m back in the saddle now, and there will be more tests of this Bulldog, as well as a couple accuracy tests of the Hatsan BT-65, which was also left hanging.

Tin Starr Bullets

The good news is that, while I was busy, Johnny Hill of Tin Starr Bullets made me a bunch of new bullets. I like his bullets because they’re pure lead and very soft. That seems to make a difference when it comes to accuracy. Last time, I tried his bullets that were sized 0.356, but today I’ll show you what they do at 0.357 inches. The difference is dramatic!

I also ordered and received some Air Venturi bullets, as well as some 9mm diabolo pellets. Today, I’ll test some of these for you.

If you read part 3, you’ll see that the 145-grain Nosler Ballistic Tip bullet does well in the Bulldog. But I thought the rifle could do better than just well, and I was hoping that the lighter Tin Starr pure lead bullets would do the trick.

The day was perfect with no wind, though wind doesn’t play much with accuracy in big bores at 50 yards. The Bulldog had been emptied of air from the last test when I checked the air release system to measure the trigger-pull. And the rifle woke up immediately with a fresh 3,000 psi fill.

Benjamin Bulldog Tom Shoots
I tested a good number of bullets and pellets in the Bulldog.

Tin Starr 101-grain SWC

The first bullet I tested was the 101-grain semi-wadcutter from Tin Starr. I figured the Bulldog would do best with a lighter bullet, and this was the second-lightest and the shortest bullet I had. The first group was okay, but not outstanding. Five bullets went into 3.081 inches at 50 yards, which isn’t stellar, but 4 of those bullets are in 1.659 inches, and they’re centered in the bull. That caught my attention. I figured if there was time remaining at the end of the session, I would return to this bullet.

Benjamin Bulldog Tin Starr 101
Five Tin Starr 101-grain semi-wadcutters are in 3.081 inches, but 4 of them are centered on the bull in 1.659 inches. This is worth a second look.

Air management

If you recall, I tested the Bulldog for velocity back in part 2, when I shot my chronograph. I learned at that time that the first 5 shots are probably the best, so I divided today’s test into a first magazine/second magazine test. I kept track of which magazine was in the fill for each bullet and noted it on the target.

I also tested velocity today. At the end of this test, I’ll show you the chronograph numbers for 10 shots with a selected bullet.

Tin Starr 108-grain truncated cone

After the 101-grain semi-wadcutter came the 108-grain Tin Starr truncated cone bullet. This was the second magazine after a fill. Five bullets went into 3.267 inches at 50 yards. This group is more open than the first one, so I didn’t pursue it any farther on this day.

Benjamin Bulldog Tin Starr 108
Five Tin Starr 108-grain truncated cone bullets went into 3.267 inches at 50 yards from the second magazine of air.

Air Venturi round ball

After 2 magazines (10 shots), I refilled the rifle to 3,000 psi and moved on to the next bullet. Next up was the 67-grain Air Venturi round ball. This is a cast bullet — not swaged, so it does have a flat from the sprue cutoff. Because the Bulldog feeds from a magazine, it’s impossible to keep the sprue aligned the same way for every shot, unless you load each ball singly.

I was surprised to see 5 of these balls go into 3.789 inches at 50 yards. That’s not too far off what I can do with my Nelson Lewis combination gun. And round balls are cheap — especially if you cast them yourself. This is a result I wasn’t expecting — finding a plinking bullet for the Bulldog. So, I decided to shoot a second magazine.

Benjamin Bulldog Air Venturi Round Ball 1
Five Air Venturi round balls went into 3.789 inches at 50 yards on the first magazine.

The second magazine of Air Venturi round balls went into 3.597 inches. What’s better, they went to the same point of impact as the first magazine. So, the Air Venturi round ball is a good plinking round for the Bulldog. It has enough power, accuracy and penetration (especially penetration!) to be good on game up to coyote size out to 50 yards.

Benjamin Bulldog Air Venturi Round Ball 2
Five Air Venturi round balls went into 3.597 inches at 50 yards on magazine two.

Now we know there are 10 good shots in the Bulldog — as long as the distance is limited to 50 yards. But airgun hunters consider 50 yards to be the distance at which long shots begin, so this is good news.

Eun Jin 9mm domed pellets

Next up were some Eun Jin 9mm pellets. These are small for the Bulldog’s bore, and we learned in part 3 that this rifle does not like bullets that measure 0.356 inches or less. Five pellets went into a large group that measured 5-7/8 inches between centers, and I stopped right there. No use wasting ammunition or air.

Benjamin Bulldog Eun Jin pellets
Eun Jin pellets scattered widely. read more


The Benjamin Bulldog big bore: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

Benjamin Bulldog
Benjamin’s new Bulldog bullpup big bore air rifle is a .357-caliber 5-shot repeater.

This report covers:

  • Scoped rifle
  • Feel of the rifle
  • Tin Starr bullets
  • Pellets are next
  • Degassing the Bulldog
  • Trigger-pull
  • What comes next

Scoped rifle

Today, I’ll take the Benjamin Bulldog to the range to try it on targets for the first time. Crosman sent me a Centerpoint 4-16X56 scope and rings for the rifle, so they were mounted before I went to the range.

Benjamin Bulldog scoped
Centerpoint 4-16X56 is sized nicely for the Bulldog.

This is the first time I have seen this particular Centerpoint scope. Pyramyd Air doesn’t carry it because it’s brand new and won’t be commercially available until later this year. I like 4-16x scopes anyway, and this one’s bright. The duplex reticle has mil-dots on both lines and appears to be etched glass. The crosshair is fine, but the mil-dots make it easy to find. The parallax focus is on the left side, where it is handy for adjustment. All in all, a nice scope!

I can’t sight-in the Bulldog in my house, so the first time I shot it at a target was on the 50-yard range. When I don’t know where the bullet is going, I always mount a larger 2-foot by 4-foot piece of paper behind the target to catch any stray shots. The bulldog was shooting about 12 inches low and to the right, but that was corrected with adjustments to the scope.

The first bullet I tried was the one I know does well in this rifle — the 145-grain Nosler Ballistic Tip. And, you’ll recall from Part 2 (velocity test) that I learned the first 5 shots are the Bulldog’s best. The second 5 shots lose a lot of velocity, and today I wanted to see what effect that has on the point of impact at 50 yards.

Feel of the rifle

Being a bullpup, the Bulldog’s sight line and comb are very straight, and I found it necessary to tilt my head over the action to see the image in the scope. Even with high rings, the scope is too low for me.

When the rifle fires, there’s a definite recoil. It’s not sharp — more of a rocket push to the rear, but it’s stronger than the recoil of a .22 long rifle in a medium-weight rifle.

Once I got the Noslers adjusted up to the bull (took about 4 shots), I settled down to shoot some groups. I filled the gun to 3,000 psi, again, and shot 5, then reloaded and shot a second 5. The first 6 bullets landed in 3.327 inches between centers, but bullet 7 hit several inches below the main group. The final 3 bullets were below the target altogether. So, the first 5 after the fill are the best with this bullet.

Benjamin Bulldog target 1
The first 6 Nosler bullets grouped in 3.327 inches at 50 yards, but shots 7 through 10 dropped lower. Only shot 7 is on the target paper (arrow). The shot next to it is one of the sighter shots and is not part of this group.

I adjusted the scope a little higher after the first group. Then, I refilled and shot again. The second group of 5 Noslers landed in 2.337 inches between centers. They’re nicely centered but still a tad low.

Benjamin Bulldog target 2
The first 5 bullets from the Bulldog after a fill are the most accurate. Five Noslers in 2.337 inches at 50 yards.

Tin Starr bullets

Following the Noslers, I had 6 different Tin Starr bullets to test. All were sized 0.356 inches, which is undersized for the Bulldog’s 0.357 bore. Airgunners are going to have to pay attention to these sizes just as they now pay attention to pellet head sizes, because they really do make a difference.

I had bullets ranging from 103 grains to 158 grains, so the gambit of bullet weights was tried. I don’t think the Bulldog can stabilize bullets longer than 158 grains; but when I shoot some more groups, I’ll know better.

All the Tin Starr bullets are pure lead — as soft as they can possibly be. My testing shows that soft bullets do best in big bore rifles. Most of the bullets landed in 5-inch or larger groups, but a 103-grain semiwadcutter did show some promise. While the 5 bullets made a 5.1-inch group, 4 of those are clustered in 2.092 inches. That gives me hope that the same bullet sized correctly may be a winner in this rifle. Remember that the AirForce Texan put five 215-grain semiwadcutters into 0.762 inches at 50 yards and 6 into 1.506 inches at 100 yards. So, we know these Tin Starr bullets work — and work well.

Benjamin Bulldog target 3
Five Tin Starr .356 bullets went into 5.1 inches at 50 yards, but 4 of them are in 2.092 inches. This shows promise.

Tin Starr has already cast and sized the same bullets in 0.357 inches for the next test. I hope to get back to the range this week.

Pellets are next

I also want to test this Bulldog with 9mm diabolo pellets. I have some on hand already, and the rest are on order. This test will continue for several more range days, because I am also writing a feature article on the Bulldog for Shotgun News.

Degassing the Bulldog

Blog reader Tim asked if there wasn’t a degassing tool to let the air out of the Bulldog’s reservoir. There isn’t, but Crosman did design a way of releasing the air.

Ed Schultz called me after reading Part 2 and told me there’s a 3/32-inch Allen screw next to the fill nipple. Loosen that and the air comes out. I checked the manual and sure enough, it’s in there!

Benjamin Bulldog degass screw
The Allen screw for degassing the Bulldog is located deep inside the stock, next to the fill nipple. read more