by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- ASG 0.30-gram BBs single action
- ASG 0.30-gram BBs double action
- TSD 0.28-gram BBs
- 0.20-gram Stealth BBs
- Thoughts about the Hop Up
- How does Hop Up work?
Today is the day we check the velocity of the Dan Wesson 715 6mm airsoft revolver, but I’m going to add some things to this report. I said in Part 1 that I would tell you how the Hop Up adjustment works and show you how to adjust it, so we’ll look at that, as well.
I usually try several different types of ammunition in a velocity test to give you a good idea of how powerful the airgun is. In the case of an airsoft gun, however, I have to constrain my test to a specific weight BB of the three most common weights — 0.12-gram, 0.20-gram and 0.25-gram. I do that because airsoft guns are designed to work best with one specific weight of ammunition and no other. In the past I have experimented with other weight BBs in some airsoft guns, but all that did was prove that the weight recommended was the best one.
This revolver is somewhat unique in that it uses a 0.30-gram BB that isn’t common. I can find one 0.28-gram BB from TSD in my inventory that I guess would be close enough, so I’l try ity, too. I guess there just aren’t that many 0.30-gram BBs around.
I will begin by testing the revolver with the 0.30-gram Blaster Devil BBs that came with the gun. In fact, let’s do that now.
ASG 0.30-gram BBs single action
This revolver operates in both the single-action and double action modes. I have discovered there is often a significant difference between these two modes, so I will test each one with this BB. I’ll start with single action. The average velocity of the 0.30-gram BB in single action was 364 f.p.s. The low was 354 f.p.s and the high was 378 f.p.s. That’s a spread of 24 f.p.s. I did pause a minimum of 10 seconds between shots to cancel the cooling effect of CO2 that tends to slow the velocity. Based on the BB weight of 4.63 grains, these BBs generate 1.36 foot-pounds of energy at the muzzle.
One reader asked me to supply energy figures, so I calculated them from the Pyramyd AIR energy formula. [I originally calculated all wrong energy numbers, based on an error in my calculations of the BB weights, but faithful readers caught it and corrected me.] Based on the BB weight of 4.63 grains, these BBs generate 1.36 foot-pounds of energy at the muzzle at the average velocity.
ASG 0.30-gram BBs double action
In double action the average velocity jumped to 411 f.p.s. with a spread from 398 f.p.s. to 422 f.p.s. That’s another 24 f.p.s. spread. At this higher velocity the muzzle energy computes to 1.74 foot-pounds. That’s demonstrates what I was saying about some guns having different velocities in single action versus double action. The revolver is rated to 450 f.p.s. and I did not see that speed in any test. The highest I got was 422 f.p.s. in double action, which is still haulin’ for a heavy 0.30-gram BB!
I noted that when loading the BBs, they had to be pushed into the nose of the cartridge. When I felt them pop in, I knew they were deep enough.
TSD 0.28-gram BBs
Now that I know the double action mode is fastest, I only tested in that mode. With 0.28-gram TSD BBs the gun averaged 439 f.p.s. The high was 453 f.p.s. and the low was 432 f.p.s. So with this slightly lighter BB we finally see the advertised velocity for the revolver.
At 4.32 grains, these BBs generated 1.85 foot-pounds at the muzzle. That’s a surprise because usually the power decreases in gas and pneumatic guns as the projectile weight declines.
0.20-gram Stealth BBs
The last BB I tried was an 0.20-gram BB with the name Stealth on the bottle and no other identification. I’ve had them for about 10 years and can’t remember where I got them, so I can’t tell you who makes them. They averaged 480 f.p.s., double action, with a spread from 476 to 484 f.p.s. These weigh 3.09 grains and generate 1.58 foot-pounds at the muzzle, which is more in keeping with what I expected.
Thoughts about the Hop Up
The Hop Up feature puts a backspin on the BB as it leaves the barrel. That makes it fly straight and true, if the spin is ideal. If it isn’t, you have to adjust it.
Correcting the Hop Up is not done by shooting at a target. What you are looking for is stable flight — not accuracy, though getting one will give you the best of the other. Stable flight means no tendency to fly off course. Some of you can already imagine how we adjust the Hop Up.
If the BB is light-colored, which the ASG BBs are, then select a large dark background to shoot at. Stand at least 30 yards away, and 40 is better, because you want to watch as much of the BB’s flight as practical. Put the sun at your back and start shooting. Watch for sudden shifts in the BB’s direction of flight. If you see them, adjust the Hop Up adjustment in one direction until you see a change in the BB’s flight. It doesn’t take much adjustment to make a change — maybe 1/8 turn of the screw will often give results.
Obviously if the BB flies worse when you adjust the screw you are going the wrong way. But there is a limit to this. You can’t adjust the gun to be more accurate than its capability. There is a point beyond which the gun will not be more accurate. So the Hop Up is used to correct obvious flight problems that appear to you as sharp curves. After the BB gets out some distance from the gun — perhaps 20-30 yards — it will start to curve more slowly in a certain direction. The Hop Up probably can’t fix that. You are looking to correct those sharp curves in flight close to the gun — not gradual curves at greater distances.
How does Hop Up work?
Hop Up is a soft flexible bumper in the bore that contacts the BB. Hop Up works by stopping the top of the BB as it travels down the bore. That puts a backspin on the BB. The amount of pressure the Hop Up puts on the BB determines the rate of backspin.
When the BB hits the rubber Hop Up bumper, the top stops and the bottom spins counter-clockwise. The amount of pressure the Hop Up puts on the BB determines the rate of backspin. The size of the bumper is enlarged here to show detail.
Obviously the Hop Up adjustment controls the depth of the rubber bumper that determines the amount of pressure it puts on the BB. More pressure means more backspin — to a point. There is a point beyond which further adjustment doesn’t do anything beyond impeding the BB’s flight. That’s why there are limits to what can be done. But without Hop Up the BB wouldn’t fly nearly as straight or as far.
Can BBs be re-used?
This answers a question asked by a reader. Airsoft BBs should not be reused. They are damaged on impact, as the photo below shows. Even the ones that aren’t cracked are made oval on impact.
If you shoot a low-powered airsoft gun and the BBs impact something soft like a blanket, then some of them can be reused. Just don’t expect great accuracy as they become oval from impact. A high-powered gun like this Dan Wesson, however, damages almost every BB it fires.
So far, so good. I have actually shot this revolver out to 30 yards, and the Hop Up is right on as it came from the box. The BBs are accurate out to 20 yards and don’t start curving until around 30 yards. When they do the curve is more gradual. I was able to hold several shots in 4 inches at 20 yards firing one-hand, unsupported. That suggests the gun is accurate. We shall see!