I finally had a chance to set up my chrono, and run some of the 18 grain JSB Exact Jumbo Heavy's through my new HW 100 T FSB, .22 cal PCP.
The specs I saw for the gun stated that the max velocity was 886 fps, but with what pellet weight? Anybody's guess, so I didn't really know what to expect with the 18 grain JSB's. I was pleasantly surprised.
After a bit of experimentation, I found that the best fill pressure for this particular rifle is 2950 psi. Just as a side note, the barrel length on this rifle is 23.6 inches. One of the longer barrels in my PCP collection.
I was pleasantly surprised to see the shots over the chrono reading in the 880+ fps range.
This rifle is a dedicated hunting gun, so a huge shot count, for my application, is not something that I focus on. In my corner of the world, here in Northern Arizona, ground squirrel hunting is not a high volume shooting affair. A couple dozen shot opportunities is a really, really good day. Half that is more like the norm.
Since the gun came with two 14 round mags, I was curious to see what the performance would be over the 28 rounds the two mags hold. That is more than enough shots for a days hunting in my area.
The air cylinder is 175cc in size. That's a bit less than my FX 2000 at 202cc. The FX gives me 32 shots at an average of 854 fps, using the same 18 grain JSB. The extreme spread is 17 fps, and fpe is 29.
I was guessing that the regulated HW 100, with 175cc air cylinder, would be similar, but with better extreme spread.
Below are the results of the chrono test.
Pellet: JSB Exact, 18 grain Jumbo Heavy.
Fill Pressure: 2950 psi.
1 - 883 15- 886
2 - 887 16- 888
3 - 886 17- 885
4 - 885 18- 888
5 - 882 19- 884
6 - 880 20- 881
7 - 881 21- 881
8 - 884 22- 887
9 - 882 23- 886
10- 880 24- 887
11- 880 25- 887
12- 882 26- 889
13- 882 27- 886
14- 888 28- 883
Hi - 889 fps
Lo - 880 fps
Avg - 884.5 fps
ES - 9 fps
SD - 3
Avg fpe - 31.4
Just for the heck of it, I put a few more pellets in the mag and fired them over the chrono. Shot number 29, clocked 875 fps, shot number 30, clocked 869 fps, and shot number 31, clocked 863 fps. It looks like 28 shots, (2 mags) is about the ideal for this rifle.
I'm more than pleased with these numbers. The sequential shot to shot consistency is really good. There were two occasions where it was 6 fps, the rest of the time it was 4 fps or less. This is going to be one heck of a good shooting rifle. Especially with the 18 grain JSB's.
Last time, I showed how she was shooting them at 15 yards indoors. A few days ago, I had a chance to sight her in at 50 yards out of doors. Yep, she's a shooter alright.
I set up my shooting stand, and put my wind flags out at 15, 25, 35, and the last one at 45 yards, five yards in front of my target frame. I also have a wind flag made from a strip of video tape that I hang on the air cylinder of my rifle.
Whenever I'm doing serious accuracy testing, or sighting in a gun, I always use my wind flags. Otherwise it's just a crap shoot, as far as what you are actually seeing down range on paper. Ideally, I would like to have a tunnel to shoot in, but since that's not going to happen, the next best thing is to use wind flags, and shoot during the lulls.
Watching the flags, and shooting only during the lulls, the following targets show the results. My hold was at 6 o'clock on the half inch orange dot.
First four shots at 50 yards. I was being patient, but not as much as I could have, because I knew I would need to make a scope adjustment. The gun is definitely going to group. The orange dot is half inch.
I made a couple of scope adjustments, waited for the next lull, and taking my time, fired a shot at a fresh orange dot. It landed dead nuts at 12 o'clock on the dot. Since the lull was holding, I fired a second shot, It landed just left of the first one, slightly enlarging the hole. The wind picked up, so I had to wait about five minutes for the next lull to appear. I got off two more shots during that lull, and they landed in with the first two, only slightly enlarging the hole. The wind picked up again, so I had to wait. When the next lull showed up, I fired off the fifth and final shot, it went through the existing hole. I don't think it even touched the paper. I put in one click of right windage and called it done.
Final five 18 grain JSB's, fired while sighting in my new HW 100 T FSB .22, at 50 yards, shooting over wind flags.
YEEHAWWW! I love it when things turn out better than expected. You don't really hear much about these guns. HW doesn't have a huge family of PCP's, like they do springers, but if my experience is typical, the one they do offer is AWESOME!
Yeah, I'm happy, real, real happy.
A few days ago, the weather was pretty nice, so I decided to get her out on a short ground squirrel hunt. That is if I could find any. It's still a bit early for them to be coming out of hibernation, but the weather has been fairly warm, so I figured I'd head out and see what I could find. You never know. Plus it's just nice being out in the woods, squirrels or no squirrels.
Here's a strong hint as to how things went. First ground squirrel of 2013, taken with a head shot at 61 yards. Yep she's a shooter.
When I have some time, I'll get a story up about the hunt. I'm just thrilled that I decided to give this rifle a try. I look forward to many successful hunts with her.