Benjamin Rogue ePCP – a new way of making airguns: Part 4
by B.B. Pelletier
Announcement: Here’s this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. He’ll receive a $50 gift card.
When we last left the Rogue, it was shooting groups on the range. Let’s return there today and learn some more of the rifle’s features.
We’ve discussed how the shooter can program the rifle for three bullet weight ranges (100, 145 and 170 grains) and three power levels (low, medium and high). Let’s look at some other things the shooter can do with the power of the gun. For example, if high power just isn’t enough, you can program the Discharge power setting. It’s above the High power setting and was explained to me by Ed Schultz of Crosman as the number 11 on a rock-band amplifier that tops out at 10.
The Discharge setting tells the valve to remain open twice as long as the High power setting for that bullet. Think of it as the analog setting that takes the Rogue back into the world of big bore airguns with mechanical valves. It wastes some air, but it gives you the absolute last word in power, considering the air pressure that remains in the reservoir. So, of course, I tried it!
It turned out to be not as dramatic as it sounded, though I may not have tried it at the place in the pressure curve where it works the best. I had just fired three shots on high power with the Nosler 145-grain bullet, and I had a very nice group starting to form downrange. With the air pressure dropping off, I thought I would boost the power to the discharge setting and shoot the fourth shot at that level to stay in the same group. Here’s what happened:
After these three shots, there was 2,447 psi remaining in the reservoir, so I boosted the power to the Discharge setting and fired the next shot.
Following that shot, 2,197 psi remained in the reservoir. That one shot on the Discharge setting used 250 psi and gave a slightly higher velocity (767, compared to 756 f.p.s.) than the previous high-power shot that had used 99 psi (2546 – 2447).
Complete user manual valve control
You also have the option of controlling the valve yourself. In that case, all programming is suspended. The valve simply remains open as long as you tell it to. Let me differentiate this from how the gun normally works.
The Rogue usually operates by sensing the air pressure remaining in the reservoir and calculating how long the valve needs to remain open, given the bullet weight you’ve selected and the power level you’re trying to achieve. As the air pressure decreases, the valve dwell time (the amount of time the valve remains open) increases to accommodate your selected performance.
When you override the programming by telling the valve how long to remain open, everything else goes out the window. The valve simply remains open that long. You might do this because you’re testing the gun’s performance with a certain bullet and think you can get a better result than the one automatically selected by the software. The dwell time can be manually controlled in increments of five microseconds. A microsecond is one-millionth of a second. It takes 1,000 microseconds to equal one millisecond. If the display reads 2000 microseconds, it means the valve will remain open for exactly 2 milliseconds.
The heart of the beast
Your next choices for time from 2000 microseconds (either longer or shorter) would be 2005 microseconds or 1995 microseconds. These are incredibly short time intervals that give you a lot of control over the valve. For those with a scientific or engineering bent, you’re now looking into the very reason why the Rogue is such a different air rifle. Other big bore valves, when they close, flutter in time increments greater than the intervals at which you can control in this rifle. That is to say — when they close, they can bounce open and closed rapidly several times before the valve closes completely. The Rogue doesn’t do that. It’s either open or it’s closed, and either you or the software controls how long it remains open to a very exacting degree.
There’s simply too much for me to tell you about the Rogue, even in a series of reports, but I know that everyone is interested in its accuracy. Remember the group I mentioned above, where I was shooting a Nosler 145-grain bullet and wanted to keep the velocity in the same place? That was the one where I set shot four to the Discharge setting to keep the velocity stable. Please look at the group I got with that approach.
Three tight shots at 50 yards with the Nosler 145-grain lead bullet. Shot four was with the rifle in the Discharge setting. Though it traveled just as fast as shot three, it strayed outside the tight group.
I also did very well with a 95-grain hollowpoint lead bullet Crosman sent me to test. On Low and Medium power, this bullet was a real tackdriver at 50 yards.
I said before that there’s not enough time left in my life to test this rifle thoroughly. But it’s proven interesting for the approximately 150 shots I’ve been able to shoot thus far. As far as conserving air, I started this test with a full 88-cubic-foot carbon fiber air tank, and it’s still able to fill the rifle to 3,000 psi, so this gun is getting far more shots per fill than any other big bore I’ve ever tested.
However, the progress on the Rogue has not ceased. The engineers at Crosman are still refining the algorithms in the software for even better air conservation. While the gun I’m now testing uses about 90 psi per shot, Crosman now has their testbed rifle using only 50 psi per shot. They’re getting 26 shots at a nominal 100 foot-pounds of muzzle energy (actually 84 to 112 foot-pounds) from 2,360 psi down to 1,098 psi. And they didn’t stop with just that.
The 170-grain bullet is delivering seven solid shots ranging from 196 foot-pounds down to 156 foot-pounds. No other big bore airgun in history has done that! Yes, the Asian 9mm rifles will give eight or nine powerful shots, but the spread of power is considerably greater than what the Rogue is now doing.
By the time they finally release the Rogue, it should be as bulletproof and exciting as it possibly can be. There’s one more thing I want you to think about.
The rifle I’m now testing is one of five pre-production prototype guns Crosman built. This gun has now been fired thousands of times. It has flown on numerous airplanes and has harvested game from around the U.S.A. ranging from 200-lb. wild pigs to gray foxes. It’s been in the hands of dozens of different shooters and, through it all, it still works. That’s as good a recommendation as I can give for any new air rifle.
I believe what Crosman should do is alter the software to allow the owner to program two different shooting programs of his own. This is similar to what can be done with a top-end metal detector or digital camera. The owners will test several bullets and valve dwell times and learn how many shots they can expect from their version of Custom 1 and Custom 2. Talk about making handloading popular!