February weather in north Texas was typical for the time of year. As the sun dropped toward the horizon, the temperature dropped below freezing as I sat in a comfortable box blind overlooking a hog feeder. A Wilson Tactical AR-style rifle stood leaning in a corner while I watched a doe and two fawns search for acorns.
Wild hogs befuddle me. I can a glimpse a whitetail’s rack and tell you within five inches what the rack will score most of the time. But, trying to guess a hog’s size is one of the most difficult tasks. I should have taken a clue to the blonde boar’s age when I spied him in thick brush beyond the game feeder that stood 80 yards away.
He stood motionless within the tangle of briars for more than five minutes studying his surroundings before he edged toward the feeder. When he finally walked under the feeder and started scrounging for corn, I still couldn’t judge his size as he stood knee deep in a muddy hole.
On cue an hour before dark, the feeder rained corn on the waiting boar. He fed for 20 minutes while I studied him through the rifle scope. Without another hog beside him to compare size, I didn’t prepare to fire. Since it was the first hunt of a three-day outing, I wasn’t in any hurry to do my part to help thin the hog population.
Without warning, the boar trotted from beneath the feeder and disappeared. Less than a minute later, a sow and her eight piglets trotted up to the feeder and started chowing down. Within five minutes, the crowd had swelled to nearly 30 hogs of all colors and sizes. I examined the biggest hogs under the feeder and realized that the first solitary hog was larger than any of the porkers now shuffling around the feeder.
Darkness fell and the hog lights cast an eerie red glow on the now vacant feeder. Stepping from the darkness, the solitary blonde boar returned to feed in peace. That’s when I determined that he was definitely big enough to rank “trophy” status. I settled the crosshairs between his eyes and squeezed off a shot. Even though the rifle was suppressed, the 7.62×40 WT (Wilson Tactical) round cracked loudly and put the hog into a pile.
It wasn’t until the boar got a ride to the skinning shed that I truly learned his size. Long tusks and his 235-pound size was evident. and a post mortem showed that the 110-grain Barnes TTSX was more than a match for the boar’s thick skull. That introduction to this new cartridge was a real eye opener.
Several months later, I got an assignment to dig deeper into this new cartridge. The first order of business was to get Bill Wilson, owner of Wilson Tactical, on the telephone to get the cartridge originator’s thoughts on the new round. We discussed and compared the new .300 Blackout to the 7.62x40WT. “If you want to shoot subsonic loads, then the Blackout is a good choice, but the 7.62x40WT really shines when you want to shoot high velocity bullets with plenty of punch,” Bill Wilson said. When he suggested that I build a complete upper in this caliber to learn more about the round’s capabilities, I agreed.
A few days later, UPS delivered a package that contained new brass, Barnes Bullets’ new 110-grain TTSX bullets, a couple boxes of Wilson Tactical’s loaded ammo and the parts needed to build a complete upper receiver.
The upper receiver build was straight forward. I installed the ejection port dust cover first to get that out of the way. Next came the forward assist plunger. A Brownell’s roll pin holder made starting the forward assist retaining pin much easier than trying to start it any other way. The same tool type was also employed to install the roll pin that holds the gas tube in a low-profile PRI gas block. (I later replaced the gas block with an adjustable PRI gas block to allow fine-tuning the gas pressure. The inside of the handguard required a bit of filing work to clear the slightly-larger gas block, but only took about 10 minutes to complete.)
Next came assembling the barrel to the upper receiver. I struggled with the barrel tensioning nut, and finally decided to grind down the jaws of an adjustable wrench to get the jaws narrow enough to fit the flats on the tensioning nut. I tensioned the nut by feel, and to just index the rear handguard screw holes when the handguard was perfectly level with the Picatinny rail on the upper receiver. If I recall correctly, torque specs for a barrel tensioning nut range from about 55-foot pound to 70-foot pounds, but it will take a dedicated tool that will allow the attachment of a torque wrench to be this precise.
The best method I have found to level a flat-top upper receiver with a handguard with a top rail is to lay the assembled parts on a perfectly flat surface when tightening the retaining screws. I use a steel welding table for this purpose.
Final assembly of the upper complete, I substituted a Bravo Company BCMGUNFIGHTER Mod 4 charging handle for a Mil Spec. Next, I attached the upper to a BCM complete lower fitted with a 6-position recoil tube. The fire control group I selected is a JP Enterprises single-stage EZ Trigger that is tuned to break precisely at 3 pounds. Completing the build was a Tactical Intent TI-7 Tactical Buttstock. (For those not familiar with Tactical Intent, they’re a division of P&S Products, which has decades of experience providing Mil Spec weapons parts.)
Once the upper receiver build was completed, I went to the range and started testing my own handloads. It was toward the end of deer season, so I carried it in the woods every chance I got, too.
Handloads
“This blue polymer tipped Barnes TTSX bullet was specifically made for this cartridge,” Bill Wilson said. “The crimp groove in the bullet is placed precisely at the point that will allow the maximum overall cartridge length of 2.60 inches, which is also the maximum length for a standard 5.56 NATO magazine.” I learned from loading heavy .308 bullets for the .300 BLK/Whisper to fit an AR magazine that cartridge overall length is limited not only by length, but by the contact of the bullet’s ogive with the magazine’s side support rib. When using polymer Magpul magazines, there’s a simple remedy. I removed the spring and follower and used a flat file to remove about half the height of the rib. This gives the bullets clearance on the sides to move freely. Wilson’s cure for what I experienced with the Magpul magazines is to sell Lancer magazines instead.
The Lancer magazines feature a modified (de-ribbed) body to enhance reliability with the 7.62×40 WT cartridge. Made in the U.S.A., the Lancers have translucent polymer bodies that are impact resistant through a wide range of temperatures. A stainless steel follower spring and hardened steel feed lips that are permanently molded into the body make these magazines double-tough.
Bill Wilson has invested a lot of time in building handloads for his pet 7.62×40 WT rifles.
My first trip to the range resulted in erratic performance from my handloads and Wilson Tactical factory loads. At first, I thought the failures to feed were underpowered handloads, but when I fired the Wilson factory loads, I had trouble with those, too. Shortly thereafter, I pulled the barrel off the upper and shipped back to Bill to have the gas port opened up. After reassembly, my next trip to the range resulted in nearly foolproof feeding and ejection. Wilson Tactical’s 125-grain load averaged 2,425 fps, produced a standard deviation of 16 fps and an extreme spread of 52 fps. Wilson Tactical 110-grain Barnes TTSX loads averaged 2,378 fps, produced a standard deviation of 32 fps and an extreme spread of 85 fps. This was the load that failed to pick up the next round from the magazine.
My first handload was 20.8 grains of H110 driving a 110-grain Barnes TTSX. Federal small rifle Match primers were used for all of my handloads. This load produced 2,340 fps from a 16-inch barrel. The standard deviation was an amazing 2 fps, and the extreme spread for 10 shots was 6 fps. The at 100 yards, best 5-shot group measured 1.232 inches.
When I switched to IMR 4227, velocities dropped with the 110-grain TTSX. A load of 19.5 grains produced 2,161 fps, a standard deviation of 25 fps, and an extreme spread of 66 fps. The smallest 5-shot group measured 1.306.
While working on several articles on the .300 BLK, I acquired several hundred Remington 125-grain bullets made to expand at lower velocities. This bullet’s nose exhibits a pink polymer tip. Since these new bullets were delivered in bulk, I took the time to weigh and sort several hundred. I found that the bullets ranged in weight by nearly 2 grains. I sorted them into groups that were within 1/10th grain and loaded those over 17.8 grains of H110. This load produced 2,002 fps, a standard deviation of 2 fps and an extreme spread of 12 fps. The smallest group measured 0.828.
Another bullet used in Advanced Armament Corporation’s development of the 300 BLK is a 125-grain hollow-point. This bullet received a charge of 17.7 grains of H110 and the velocity averaged 1,935 fps. The standard deviation was 21 fps, and the extreme spread was 43 fps. The best 5-shot group measured 2.103 inches, which had one outlier from a 4-shot cluster that measured 0.749.
I produced two loads with Nosler’s 125-grain Ballistic Tips. The first load was 23.5 grains of AA1680, which averaged 2,181 fps. The extreme spread was 98 fps, and the standard deviation was 24 fps. Loading 17.8 grains of H110, this bullet averaged 1,908 fps. An 8.7 fps standard deviation signals that this load was a consistent performer, and printed a 0.761-inch group as its best.
The last load was Hornady’s 130-grain Spire Point. This bullet was driven 1,994 fps, on average, by 19.0 grains of H110. The SD was 9.6 fps, and the ES measured 21 fps. This load’s best 5-shot group at 100 yards measured 0.675 inch.
These loads represent starting and mid-range power loads. I plan to continue test to find ideal loads. Anyone wanting to work up loads for this round should back off these and the loads suggested by Wilson Combat by 10 percent and work up.
The 7.62×40 WT gets a lot from a .30 caliber bullet on in an AR15-platform rifle. The ability to create inexpensive cases from surplus military brass is a big benefit. If you try it on whitetail-sized game, you will learn, too, that it’s a very adequate killer.
More Load Data
| Bullet | Powder | Velocity | SD | ES | Accuracy |
| 125 Nosler Ballistic Tip | 23.5 AA1680 | 2,181 | 24 | 98 | 0.761 |
| 125 Nosler Ballistic Tip | 17.8 H110 | 1,908 | 8.7 | 23 | 1.232 |
| 130 Hornady SP | 19.0 H110 | 1,994 | 9.6 | 21 | 0.675 |
| 125 Remington Pink Tip | 17.8 H110 | 2,002 | 2 | 12 | 0.828 |
| 125 AAC HP | 17.7 H110 | 1,935 | 21 | 43 | 2.103 |
| 110 Barnes TTSX** | 20.8 H110 | 2,340 | 2 | 6 | 0.965 |
| 110 Barnes TTSX | 19.5 IMR 4227 | 2,161 | 25 | 66 | 1.302 |
| Wilson Tactical Factory Loads | |||||
| 125 TNT | 2,323 | 17 | 56 | 1.298 | |
| 110 TTSX | 2,484 | 23 | 65 | 1.018 |
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