Posts Tagged ‘quick-disconnect’
by B.B. Pelletier
Today, I’ll test the velocity of the Sam Yang Big Bore .50 caliber Dragon Claw single-shot air rifle. For this test, I used two Air Venturi bullets and a swaged round ball that are available from Pyramyd Air.
The rifle is supplied with a probe-type quick-disconnect fill device, and I can finally report that the Koreans have now conformed with the rest of the world in supplying these adapters with standard threads that attach to common 1/8″ BSP fittings. In the past it was a chore matching these adapters to hoses you might have on hand (if you’re already into PCP airguns).
The No. 1 recommendation I have if you’re buying the Dragon Claw as your first PCP is that you also purchase the Pyramyd Air Quick-Disconnect male fitting and switch out the fill port on your rifle. Then, you can fill from a variety of high-pressure air devices, including the Air Venturi 88 cu ft carbon fiber tank. You’re going to want something that large to keep this monster gun supplied with air.
Let me address the air issue right now. This rifle does use a lot of air. I found that I got four useable shots on high power or eight shots on low power, and each time I did that the gun dropped from 3,000 psi to 1,500 psi for high power and 1,200 psi for low power. This number of shots per fill is fairly good considering the caliber of the rifle, but you’re going to refill it often. Don’t even think of using a hand pump for this rifle!
Shot with open sights
I decided to shoot the velocity test shots with open sights to simplify things at the range, and in so doing I learned that this rifle shoots very low at 50 yards. So low, in fact, that it was impossible to move the point of impact up to the point of aim. That’s good to know, because I’ll want to use a scope mount with some droop correction for the accuracy test.
The rifle actually grouped pretty well with open sights, considering I was shooting three different projectiles at two different power levels for each. Of the approximately 25 shots I fired, about 21 grouped in a hand-sized group. Unfortunately, it was below the target paper, so I’ll leave all accuracy testing to Part 3. But this test did show me a couple things about the gun.
I know why there’s a low-power level
First, you may remember that I was skeptical about using the low-power level. Now I know why it’s useful. With the Air Venturi 200-grain round nose lead bullet, the rifle gave eight good shots on low power — and they all went into that group I mentioned. When I scope the rifle for the accuracy test, this is one power level I’ll definitely try.
On low power, the 200-grain bullet ranged from a low of 562 f.p.s. to a high of 613 f.p.s. The average was 598 f.p.s., which gives us a muzzle energy of 158.85 foot-pounds. That’s for eight shots on low power.
On high power, I got four good shots from all the bullets. The 200-grain bullets ranged from 687 f.p.s down to 610 f.p.s., with an average of 640 f.p.s. That’s an average muzzle energy of 181.95 foot-pounds. So, I got half the number of shots for a 23 foot-pound gain. It doesn’t seem worth it to me. They did group with the other 200-grain bullets, though.
The 225-grain Air Venturi round nose lead bullets also gave four good shots on high power. They ranged from 652 f.p.s. down to 581 f.p.s., with the average at 614 f.p.s. That’s an average muzzle energy of 188.4 foot-pounds. That’s not much better than the 200-grain bullets, so I think I’ll stick with the lighter bullets. These bullets also went into the main group with everything else.
On low power, the 225-grain bullets gave eight good shots, ranging from 614 f.p.s down to 521 f.p.s., with the average at 563 f.p.s. That’s an average muzzle energy of 158.4 foot-pounds. They also went into the main group at 50 yards.
It was the Hornady .495-inch round balls that didn’t do so well in this gun. They averaged just 465 f.p.s., so they must fit the bore very loosely. Since the balls weigh only 183 grains, the average energy was just 87.77 foot-pounds. They did not group with the other bullets. They were about six inches lower than the main group, though centered with it.
The Dragon Claw has a heavy trigger. I would estimate that it releases with about 8 lbs. of pull, and there’s considerable creep in the pull. The rifle recoils about like a lightweight .22 Magnum rifle or even a .38 Special fired from a rifle. A friend at the range noticed the recoil when I fired.
The gun cocks by pulling back on the spring-loaded hammer. It’s stiff in a new gun, and it takes a bit of finesse to stop on the low-power setting. The tendency is to haul back as hard as you can, which takes you right to high power.
Observations thus far
The Dragon Claw is a handy big bore that’s got plenty of power and is priced right for the category. It seems to be very good on low power, and I’m looking forward to shooting it with a scope.
Are there .17 caliber firearms?
J-F, one of our Canadian blog readers, asked this question and I thought I’d answer him here. Yes, there are plenty of .17 caliber firearms; though, just like the .22 calibers, they’re not the same size as airguns. In the case of .17 caliber, the firearm bullets are all smaller.
Two very popular .17 caliber firearms these days are the .17 HMR — that’s a .22 Winchester Magnum rimfire necked down to .17 caliber — and the .17 HM2, which is a .22 long rifle necked down. The HMR leads the HM2 in the popularity contest, even though the ammunition is three times more expensive.
I have a .17 HM2 rifle that a friend of mine built for me on a Hungarian single-shot .22 long rifle action. You’ve seen this rifle before, because it’s the same gun I used for testing the Blue Wonder cold bluing process. And, the blue is still beautiful on that barrel, despite my never wiping the gun down and purposely handling the barrel to see if I could get the finish to wear.
The .17 HM2 cartridges are based on the .22 long rifle round.
My .17 HM2 rifle is based on a Hungarian single-shot trainer. I blued the barrel with Blue Wonder cold blue in another report.
I cleaned the barrel just for this report, so naturally I had to shoot several rounds to foul the bore again. A clean barrel almost never shoots to the same point of aim as a slightly dirty one. Once I was satisfied that the rounds had stopped walking, I adjusted the sights and shot a five-shot group at 50 yards. It’s no great group, and several PCPs I’ve tested will beat it hands-down, but it’s in the right place.
Not great but also not terrible for open sights at 50 yards. The .17 HM2 is a nice, inexpensive varmint cartridge.
So, yes, there are .17 caliber firearms, as well as pellet guns. That’s my report for today. Next time, I’ll have a scope on the Dragon Claw, and we’ll see how well she can do.